diff --git a/fennel.lua b/fennel.lua
index ec5cef1..6663866 100644
--- a/fennel.lua
+++ b/fennel.lua
@@ -30,20 +30,42 @@ local unpack = unpack or table.unpack
 -- Main Types and support functions
 --
 
+-- Map function f over sequential table t, removing values where f returns nil.
+-- Optionally takes a target table to insert the mapped values into.
+local function map(t, f, out)
+    out = out or {}
+    if type(f) ~= "function" then local s = f f = function(x) return x[s] end end
+    for _,x in ipairs(t) do
+        local v = f(x)
+        if v then table.insert(out, v) end
+    end
+    return out
+end
+
+-- Map function f over key/value table t, similar to above, but it can return a
+-- sequential table if f returns a single value or a k/v table if f returns two.
+-- Optionally takes a target table to insert the mapped values into.
+local function kvmap(t, f, out)
+    out = out or {}
+    if type(f) ~= "function" then local s = f f = function(x) return x[s] end end
+    for k,x in pairs(t) do
+        local korv, v = f(k, x)
+        if korv and not v then table.insert(out, korv) end
+        if korv and v then out[korv] = v end
+    end
+    return out
+end
+
 local function deref(self) return self[1] end
 
-local SYMBOL_MT = { 'SYMBOL', __tostring = deref }
+local function listToString(self, tostring2)
+    return '(' .. table.concat(map(self, tostring2 or tostring), ' ', 1, #self) .. ')'
+end
+
+local SYMBOL_MT = { 'SYMBOL', __tostring = deref, __fennelview = deref }
 local EXPR_MT = { 'EXPR', __tostring = deref }
 local VARARG = setmetatable({ '...' }, { 'VARARG', __tostring = deref })
-local LIST_MT = { 'LIST',
-    __tostring = function (self)
-        local strs = {}
-        for _, s in ipairs(self) do
-            table.insert(strs, tostring(s))
-        end
-        return '(' .. table.concat(strs, ' ', 1, #self) .. ')'
-    end
-}
+local LIST_MT = { 'LIST', __tostring = listToString, __fennelview = listToString }
 local SEQUENCE_MT = { 'SEQUENCE' }
 
 -- Load code with an environment in all recent Lua versions
@@ -58,23 +80,28 @@ local function loadCode(code, environment, filename)
     end
 end
 
--- Create a new list
+-- Create a new list. Lists are a compile-time construct in Fennel; they are
+-- represented as tables with a special marker metatable. They only come from
+-- the parser, and they represent code which comes from reading a paren form;
+-- they are specifically not cons cells.
 local function list(...)
     return setmetatable({...}, LIST_MT)
 end
 
--- Create a new symbol
+-- Create a new symbol. Symbols are a compile-time construct in Fennel and are
+-- not exposed outside the compiler. Symbols have metadata describing what file,
+-- line, etc that they came from.
 local function sym(str, scope, meta)
     local s = {str, scope = scope}
-    if meta then
-        for k, v in pairs(meta) do
-            if type(k) == 'string' then s[k] = v end
-        end
+    for k, v in pairs(meta or {}) do
+        if type(k) == 'string' then s[k] = v end
     end
     return setmetatable(s, SYMBOL_MT)
 end
 
--- Create a new sequence
+-- Create a new sequence. Sequences are tables that come from the parser when
+-- it encounters a form with square brackets. They are treated as regular tables
+-- except when certain macros need to look for binding forms, etc specifically.
 local function sequence(...)
    return setmetatable({...}, SEQUENCE_MT)
 end
@@ -120,6 +147,13 @@ local function isSequence(x)
    return type(x) == 'table' and getmetatable(x) == SEQUENCE_MT and x
 end
 
+-- Returns a shallow copy of its table argument. Returns an empty table on nil.
+local function copy(from)
+   local to = {}
+   for k, v in pairs(from or {}) do to[k] = v end
+   return to
+end
+
 --
 -- Parser
 --
@@ -196,6 +230,11 @@ local prefixes = { -- prefix chars substituted while reading
     [35] = 'hashfn' -- #
 }
 
+-- The resetRoot function needs to be called at every exit point of the compiler
+-- including when there's a parse error or compiler error. Introduce it up here
+-- so error functions have access to it, and set it when we have values below.
+local resetRoot = nil
+
 -- Parse one value given a function that
 -- returns sequential bytes. Will throw an error as soon
 -- as possible without getting more bytes on bad input. Returns
@@ -228,6 +267,7 @@ local function parser(getbyte, filename)
         return r
     end
     local function parseError(msg)
+        if resetRoot then resetRoot() end
         return error(msg .. ' in ' .. (filename or 'unknown') .. ':' .. line, 0)
     end
 
@@ -254,10 +294,7 @@ local function parser(getbyte, filename)
         -- Throw nice error when we expect more characters
         -- but reach end of stream.
         local function badend()
-            local accum = {}
-            for _, item in ipairs(stack) do
-                accum[#accum + 1] = item.closer
-            end
+            local accum = map(stack, "closer")
             parseError(('expected closing delimiter%s %s'):format(
                 #stack == 1 and "" or "s",
                 string.char(unpack(accum))))
@@ -317,7 +354,8 @@ local function parser(getbyte, filename)
                     end
                     val = {}
                     for i = 1, #last, 2 do
-                        if tostring(last[i]) == ":" and isSym(last[i + 1]) then
+                        if(tostring(last[i]) == ":" and isSym(last[i + 1])
+                           and isSym(last[i])) then
                             last[i] = tostring(last[i + 1])
                         end
                         val[last[i]] = last[i + 1]
@@ -376,7 +414,7 @@ local function parser(getbyte, filename)
                 if rawstr == 'true' then dispatch(true)
                 elseif rawstr == 'false' then dispatch(false)
                 elseif rawstr == '...' then dispatch(VARARG)
-                elseif rawstr:match('^:.+$') then -- keyword style strings
+                elseif rawstr:match('^:.+$') then -- colon style strings
                     dispatch(rawstr:sub(2))
                 elseif rawstr:match("^~") and rawstr ~= "~=" then
                     -- for backwards-compatibility, special-case allowance of ~=
@@ -424,15 +462,25 @@ end
 --
 
 -- Top level compilation bindings.
-local rootChunk
-local rootScope
-local rootOptions
+local rootChunk, rootScope, rootOptions
 
--- Create a new Scope, optionally under a parent scope. Scopes are compile time constructs
--- that are responsible for keeping track of local variables, name mangling, and macros.
--- They are accessible to user code via the '*compiler' special form (may change). They
--- use metatables to implement nesting via inheritance.
+local function setResetRoot(oldChunk, oldScope, oldOptions)
+    local oldResetRoot = resetRoot -- this needs to nest!
+    resetRoot = function()
+        rootChunk, rootScope, rootOptions = oldChunk, oldScope, oldOptions
+        resetRoot = oldResetRoot
+    end
+end
+
+local GLOBAL_SCOPE
+
+-- Create a new Scope, optionally under a parent scope. Scopes are compile time
+-- constructs that are responsible for keeping track of local variables, name
+-- mangling, and macros.  They are accessible to user code via the
+-- 'eval-compiler' special form (may change). They use metatables to implement
+-- nesting via metatables.
 local function makeScope(parent)
+    if not parent then parent = GLOBAL_SCOPE end
     return {
         unmanglings = setmetatable({}, {
             __index = parent and parent.unmanglings
@@ -449,6 +497,9 @@ local function makeScope(parent)
         includes = setmetatable({}, {
             __index = parent and parent.includes
         }),
+        refedglobals = setmetatable({}, {
+            __index = parent and parent.refedglobals
+        }),
         autogensyms = {},
         parent = parent,
         vararg = parent and parent.vararg,
@@ -462,6 +513,7 @@ end
 local function assertCompile(condition, msg, ast)
     -- if we use regular `assert' we can't provide the `level' argument of zero
     if not condition then
+        if resetRoot then resetRoot() end
         error(string.format("Compile error in '%s' %s:%s: %s",
                             isSym(ast[1]) and ast[1][1] or ast[1] or '()',
                             ast.filename or "unknown", ast.line or '?', msg), 0)
@@ -469,7 +521,7 @@ local function assertCompile(condition, msg, ast)
     return condition
 end
 
-local GLOBAL_SCOPE = makeScope()
+GLOBAL_SCOPE = makeScope()
 GLOBAL_SCOPE.vararg = true
 local SPECIALS = GLOBAL_SCOPE.specials
 local COMPILER_SCOPE = makeScope(GLOBAL_SCOPE)
@@ -479,9 +531,8 @@ local luaKeywords = {
     'if', 'in', 'local', 'nil', 'not', 'or', 'repeat', 'return', 'then', 'true',
     'until', 'while'
 }
-for i, v in ipairs(luaKeywords) do
-    luaKeywords[v] = i
-end
+
+for i, v in ipairs(luaKeywords) do luaKeywords[v] = i end
 
 local function isValidLuaIdentifier(str)
     return (str:match('^[%a_][%w_]*$') and not luaKeywords[str])
@@ -553,21 +604,31 @@ end
 local function globalUnmangling(identifier)
     local rest = identifier:match('^__fnl_global__(.*)$')
     if rest then
-        return rest:gsub('_[%da-f][%da-f]', function (code)
+        local r = rest:gsub('_[%da-f][%da-f]', function (code)
             return string.char(tonumber(code:sub(2), 16))
         end)
+        return r -- don't return multiple values
     else
         return identifier
     end
 end
 
+-- If there's a provided list of allowed globals, don't let references thru that
+-- aren't on the list. This list is set at the compiler entry points of compile
+-- and compileStream.
+local allowedGlobals
+
+local function globalAllowed(name)
+    if not allowedGlobals then return true end
+    for _, g in ipairs(allowedGlobals) do
+        if g == name then return true end
+    end
+end
+
 -- Creates a symbol from a string by mangling it.
 -- ensures that the generated symbol is unique
 -- if the input string is unique in the scope.
-local function localMangling(str, scope, ast)
-    if scope.manglings[str] then
-        return scope.manglings[str]
-    end
+local function localMangling(str, scope, ast, tempManglings)
     local append = 0
     local mangling = str
     assertCompile(not isMultiSym(str), 'did not expect multi symbol ' .. str, ast)
@@ -581,16 +642,30 @@ local function localMangling(str, scope, ast)
         return ('_%02x'):format(c:byte())
     end)
 
+    -- Prevent name collisions with existing symbols
     local raw = mangling
     while scope.unmanglings[mangling] do
         mangling = raw .. append
         append = append + 1
     end
+
     scope.unmanglings[mangling] = str
-    scope.manglings[str] = mangling
+    local manglings = tempManglings or scope.manglings
+    manglings[str] = mangling
     return mangling
 end
 
+-- Calling this function will mean that further
+-- compilation in scope will use these new manglings
+-- instead of the current manglings.
+local function applyManglings(scope, newManglings, ast)
+    for raw, mangled in pairs(newManglings) do
+        assertCompile(not scope.refedglobals[mangled],
+        "use of global " .. raw .. " is aliased by a local", ast)
+        scope.manglings[raw] = mangled
+    end
+end
+
 -- Combine parts of a symbol
 local function combineParts(parts, scope)
     local ret = scope.manglings[parts[1]] or globalMangling(parts[1])
@@ -637,32 +712,20 @@ local function checkBindingValid(symbol, scope, ast)
     assertCompile(not scope.specials[name],
     ("symbol %s may be overshadowed by a special form or macro"):format(name), ast)
     assertCompile(not isQuoted(symbol), 'macro tried to bind ' .. name ..
-                      ' without gensym; try ' .. name .. '# instead', ast)
+                      " without gensym; try ' .. name .. '# instead", ast)
 
 end
 
 -- Declare a local symbol
-local function declareLocal(symbol, meta, scope, ast)
+local function declareLocal(symbol, meta, scope, ast, tempManglings)
     checkBindingValid(symbol, scope, ast)
     local name = symbol[1]
     assertCompile(not isMultiSym(name), "did not expect mutltisym", ast)
-    local mangling = localMangling(name, scope, ast)
+    local mangling = localMangling(name, scope, ast, tempManglings)
     scope.symmeta[name] = meta
     return mangling
 end
 
--- If there's a provided list of allowed globals, don't let references
--- thru that aren't on the list. This list is set at the compiler
--- entry points of compile and compileStream.
-local allowedGlobals
-
-local function globalAllowed(name)
-    if not allowedGlobals then return true end
-    for _, g in ipairs(allowedGlobals) do
-        if g == name then return true end
-    end
-end
-
 -- Convert symbol to Lua code. Will only work for local symbols
 -- if they have already been declared via declareLocal
 local function symbolToExpression(symbol, scope, isReference)
@@ -685,6 +748,9 @@ local function symbolToExpression(symbol, scope, isReference)
     -- then we need to check for allowed globals
     assertCompile(not isReference or isLocal or globalAllowed(parts[1]),
                   'unknown global in strict mode: ' .. parts[1], symbol)
+    if not isLocal then
+        rootScope.refedglobals[parts[1]] = true
+    end
     return expr(combineParts(parts, scope), etype)
 end
 
@@ -709,10 +775,7 @@ local function peephole(chunk)
         return peephole(chunk[2])
     end
     -- Recurse
-    for i, v in ipairs(chunk) do
-        chunk[i] = peephole(v)
-    end
-    return chunk
+    return map(chunk, peephole)
 end
 
 -- correlate line numbers in input with line numbers in output
@@ -753,15 +816,13 @@ local function flattenChunk(sm, chunk, tab, depth)
         if sm then sm[#sm + 1] = info and info.line or -1 end
         return code
     else
-        local parts = {}
-        for i = 1, #chunk do
-            -- Ignore empty chunks
-            if chunk[i].leaf or #(chunk[i]) > 0 then
-                local sub = flattenChunk(sm, chunk[i], tab, depth + 1)
+        local parts = map(chunk, function(c)
+            if c.leaf or #c > 0 then -- Ignore empty chunks
+                local sub = flattenChunk(sm, c, tab, depth + 1)
                 if depth > 0 then sub = tab .. sub:gsub('\n', '\n' .. tab) end
-                table.insert(parts, sub)
+                return sub
             end
-        end
+        end)
         return table.concat(parts, '\n')
     end
 end
@@ -851,16 +912,12 @@ end
 
 local function docSpecial(name, arglist, docstring)
     metadata[SPECIALS[name]] =
-        { ['fnl/docstring'] = docstring, ['fnl/arglist'] = arglist }
+        { ["fnl/docstring"] = docstring, ["fnl/arglist"] = arglist }
 end
 
 -- Convert expressions to Lua string
 local function exprs1(exprs)
-    local t = {}
-    for _, e in ipairs(exprs) do
-        t[#t + 1] = e[1]
-    end
-    return table.concat(t, ', ')
+    return table.concat(map(exprs, 1), ', ')
 end
 
 -- Compile side effects for a chunk
@@ -937,6 +994,17 @@ end
 --   'tail' - boolean indicating tail position if set. If set, form will generate a return
 --   instruction.
 --   'nval' - The number of values to compile to if it is known to be a fixed value.
+
+-- In Lua, an expression can evaluate to 0 or more values via multiple
+-- returns. In many cases, Lua will drop extra values and convert a 0 value
+-- expression to nil. In other cases, Lua will use all of the values in an
+-- expression, such as in the last argument of a function call. Nval is an
+-- option passed to compile1 to say that the resulting expression should have
+-- at least n values. It lets us generate better code, because if we know we
+-- are only going to use 1 or 2 values from an expression, we can create 1 or 2
+-- locals to store intermediate results rather than turn the expression into a
+-- closure that is called immediately, which we have to do if we don't know.
+
 local function compile1(ast, scope, parent, opts)
     opts = opts or {}
     local exprs = {}
@@ -1038,24 +1106,23 @@ local function compile1(ast, scope, parent, opts)
             local nval = i ~= #ast and 1
             buffer[#buffer + 1] = exprs1(compile1(ast[i], scope, parent, {nval = nval}))
         end
-        local keys = {}
-        for k, _ in pairs(ast) do -- Write other keys.
+        local function writeOtherValues(k)
             if type(k) ~= 'number' or math.floor(k) ~= k or k < 1 or k > #ast then
-                local kstr
                 if type(k) == 'string' and isValidLuaIdentifier(k) then
-                    kstr = k
+                    return {k, k}
                 else
-                    kstr = '[' .. tostring(compile1(k, scope, parent, {nval = 1})[1]) .. ']'
+                    local kstr = '[' .. tostring(compile1(k, scope, parent,
+                                                          {nval = 1})[1]) .. ']'
+                    return { kstr, k }
                 end
-                table.insert(keys, { kstr, k })
             end
         end
+        local keys = kvmap(ast, writeOtherValues)
         table.sort(keys, function (a, b) return a[1] < b[1] end)
-        for _, k in ipairs(keys) do
-            local v = ast[k[2]]
-            buffer[#buffer + 1] = ('%s = %s'):format(
-                k[1], tostring(compile1(v, scope, parent, {nval = 1})[1]))
-        end
+        map(keys, function(k)
+                local v = tostring(compile1(ast[k[2]], scope, parent, {nval = 1})[1])
+                return ('%s = %s'):format(k[1], v) end,
+            buffer)
         local tbl = '{' .. table.concat(buffer, ', ') ..'}'
         exprs = handleCompileOpts({expr(tbl, 'expression')}, parent, opts, ast)
     else
@@ -1096,13 +1163,15 @@ local function destructure(to, from, ast, scope, parent, opts)
     local forceset = opts.forceset
     local setter = declaration and "local %s = %s" or "%s = %s"
 
+    local newManglings = {}
+
     -- Get Lua source for symbol, and check for errors
     local function getname(symbol, up1)
         local raw = symbol[1]
         assertCompile(not (nomulti and isMultiSym(raw)),
             'did not expect multisym', up1)
         if declaration then
-            return declareLocal(symbol, {var = isvar}, scope, symbol)
+            return declareLocal(symbol, {var = isvar}, scope, symbol, newManglings)
         else
             local parts = isMultiSym(raw) or {raw}
             local meta = scope.symmeta[parts[1]]
@@ -1114,6 +1183,16 @@ local function destructure(to, from, ast, scope, parent, opts)
                 assertCompile(not (meta and not meta.var),
                     'expected local var', up1)
             end
+            if forceglobal then
+                assertCompile(not scope.symmeta[scope.unmanglings[raw]],
+                              "global " .. raw .. " conflicts with local", ast)
+                scope.manglings[raw] = globalMangling(raw)
+                scope.unmanglings[globalMangling(raw)] = raw
+                if allowedGlobals then
+                    table.insert(allowedGlobals, raw)
+                end
+            end
+
             return symbolToExpression(symbol, scope)[1]
         end
     end
@@ -1121,10 +1200,8 @@ local function destructure(to, from, ast, scope, parent, opts)
     -- Compile the outer most form. We can generate better Lua in this case.
     local function compileTopTarget(lvalues)
         -- Calculate initial rvalue
-        local inits = {}
-        for _, x in ipairs(lvalues) do
-            table.insert(inits, scope.manglings[x] and x or 'nil')
-        end
+        local inits = map(lvalues, function(x)
+                              return scope.manglings[x] and x or 'nil' end)
         local init = table.concat(inits, ', ')
         local lvalue = table.concat(lvalues, ', ')
 
@@ -1198,7 +1275,9 @@ local function destructure(to, from, ast, scope, parent, opts)
         if top then return {returned = true} end
     end
 
-    return destructure1(to, nil, ast, true)
+    local ret = destructure1(to, nil, ast, true)
+    applyManglings(scope, newManglings, ast)
+    return ret
 end
 
 -- Unlike most expressions and specials, 'values' resolves with multiple
@@ -1234,6 +1313,15 @@ local function compileDo(ast, scope, parent, start)
     end
 end
 
+-- Raises compile error if unused locals are found and we're checking for them.
+local function checkUnused(scope, ast)
+    if not rootOptions.checkUnusedLocals then return end
+    for symName in pairs(scope.symmeta) do
+        assertCompile(scope.symmeta[symName].used or symName:find("^_"),
+                      ("unused local %s"):format(symName), ast)
+    end
+end
+
 -- Implements a do statement, starting at the 'start' element. By default, start is 2.
 local function doImpl(ast, scope, parent, opts, start, chunk, subScope)
     start = start or 2
@@ -1293,20 +1381,21 @@ local function doImpl(ast, scope, parent, opts, start, chunk, subScope)
     end
     emit(parent, chunk, ast)
     emit(parent, 'end', ast)
+    checkUnused(subScope, ast)
     return retexprs
 end
 
-SPECIALS['do'] = doImpl
-docSpecial('do', {'...'}, 'Evaluate multiple forms; return last value.')
+SPECIALS["do"] = doImpl
+docSpecial("do", {"..."}, "Evaluate multiple forms; return last value.")
 
-SPECIALS['values'] = values
-docSpecial('values', {'...'},
-           'Return multiple values from a function.  Must be in tail position.')
+SPECIALS["values"] = values
+docSpecial("values", {"..."},
+           "Return multiple values from a function.  Must be in tail position.")
 
 -- The fn special declares a function. Syntax is similar to other lisps;
 -- (fn optional-name [arg ...] (body))
 -- Further decoration such as docstrings, meta info, and multibody functions a possibility.
-SPECIALS['fn'] = function(ast, scope, parent)
+SPECIALS["fn"] = function(ast, scope, parent)
     local fScope = makeScope(scope)
     local fChunk = {}
     local index = 2
@@ -1327,25 +1416,26 @@ SPECIALS['fn'] = function(ast, scope, parent)
         fnName = gensym(scope)
     end
     local argList = assertCompile(isTable(ast[index]),
-                                  'expected vector arg list [a b ...]', ast)
-    local argNameList = {}
-    for i = 1, #argList do
-        if isVarg(argList[i]) then
-            assertCompile(i == #argList, "expected vararg in last parameter position", ast)
-            argNameList[i] = '...'
+                                  "expected vector arg list [a b ...]", ast)
+    local function getArgName(i, name)
+        if isVarg(name) then
+            assertCompile(i == #argList, "expected vararg as last parameter", ast)
             fScope.vararg = true
-        elseif(isSym(argList[i]) and argList[i][1] ~= "nil"
-               and not isMultiSym(argList[i][1])) then
-            argNameList[i] = declareLocal(argList[i], {}, fScope, ast)
-        elseif isTable(argList[i]) then
+            return "..."
+        elseif(isSym(name) and deref(name) ~= "nil"
+               and not isMultiSym(deref(name))) then
+            return declareLocal(name, {}, fScope, ast)
+        elseif isTable(name) then
             local raw = sym(gensym(scope))
-            argNameList[i] = declareLocal(raw, {}, fScope, ast)
-            destructure(argList[i], raw, ast, fScope, fChunk,
+            local declared = declareLocal(raw, {}, fScope, ast)
+            destructure(name, raw, ast, fScope, fChunk,
                         { declaration = true, nomulti = true })
+            return declared
         else
-            assertCompile(false, 'expected symbol for function parameter', ast)
+            assertCompile(false, "expected symbol for function parameter", ast)
         end
     end
+    local argNameList = kvmap(argList, getArgName)
     if type(ast[index + 1]) == 'string' and index + 1 < #ast then
         index = index + 1
         docstring = ast[index]
@@ -1368,11 +1458,10 @@ SPECIALS['fn'] = function(ast, scope, parent)
     emit(parent, 'end', ast)
 
     if rootOptions.useMetadata then
-        local args = {}
-        for i, v in ipairs(argList) do
+        local args = map(argList, function(v)
             -- TODO: show destructured args properly instead of replacing
-            args[i] =  isTable(v) and '"#<table>"' or string.format('"%s"', tostring(v))
-        end
+            return isTable(v) and '"#<table>"' or string.format('"%s"', tostring(v))
+        end)
 
         local metaFields = {
             '"fnl/arglist"', '{' .. table.concat(args, ', ') .. '}',
@@ -1388,13 +1477,14 @@ SPECIALS['fn'] = function(ast, scope, parent)
                                    fnName, table.concat(metaFields, ', ')))
     end
 
+    checkUnused(fScope, ast)
     return expr(fnName, 'sym')
 end
-docSpecial('fn', {'name?', 'args', 'docstring?', '...'},
-           'Function syntax. May optionally include a name and docstring.'
-               ..'\nIf a name is provided, the function will be bound in the current scope.'
-               ..'\nWhen called with the wrong number of args, excess args will be discarded'
-               ..'\nand lacking args will be nil; use lambda for arity-checked functions.')
+docSpecial("fn", {"name?", "args", "docstring?", "..."},
+           "Function syntax. May optionally include a name and docstring."
+               .."\nIf a name is provided, the function will be bound in the current scope."
+               .."\nWhen called with the wrong number of args, excess args will be discarded"
+               .."\nand lacking args will be nil, use lambda for arity-checked functions.")
 
 -- (lua "print('hello!')") -> prints hello, evaluates to nil
 -- (lua "print 'hello!'" "10") -> prints hello, evaluates to the number 10
@@ -1427,11 +1517,11 @@ SPECIALS['doc'] = function(ast, scope, parent)
             :format(rootOptions.moduleName or "fennel", value, tostring(ast[2]))
     end
 end
-docSpecial('doc', {'x'},
-           'Print the docstring and arglist for a function, macro, or special form.')
+docSpecial("doc", {"x"},
+           "Print the docstring and arglist for a function, macro, or special form.")
 
 -- Table lookup
-SPECIALS['.'] = function(ast, scope, parent)
+SPECIALS["."] = function(ast, scope, parent)
     local len = #ast
     assertCompile(len > 1, "expected table argument", ast)
     local lhs = compile1(ast[2], scope, parent, {nval = 1})
@@ -1456,51 +1546,45 @@ SPECIALS['.'] = function(ast, scope, parent)
         end
     end
 end
-docSpecial('.', {'tbl', 'key1', '...'},
-           'Look up key1 in tbl table. If more args are provided, do a nested lookup.')
+docSpecial(".", {"tbl", "key1", "..."},
+           "Look up key1 in tbl table. If more args are provided, do a nested lookup.")
 
-SPECIALS['global'] = function(ast, scope, parent)
+SPECIALS["global"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
-    -- globals tracking doesn't currently work with multi-values/destructuring
-    if allowedGlobals and isSym(ast[2]) then
-        for _,global in ipairs(isList(ast[2]) and ast[2] or {ast[2]}) do
-            table.insert(allowedGlobals, deref(global))
-        end
-    end
     destructure(ast[2], ast[3], ast, scope, parent, {
         nomulti = true,
         forceglobal = true
     })
 end
-docSpecial('global', {'name', 'val'}, 'Set name as a global with val.')
+docSpecial("global", {"name", "val"}, "Set name as a global with val.")
 
-SPECIALS['set'] = function(ast, scope, parent)
+SPECIALS["set"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         noundef = true
     })
 end
-docSpecial('set', {'name', 'val'},
-           'Set a local variable to a new value. Only works on locals using var.')
+docSpecial("set", {"name", "val"},
+           "Set a local variable to a new value. Only works on locals using var.")
 
-SPECIALS['set-forcibly!'] = function(ast, scope, parent)
+SPECIALS["set-forcibly!"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         forceset = true
     })
 end
 
-SPECIALS['local'] = function(ast, scope, parent)
+SPECIALS["local"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         declaration = true,
         nomulti = true
     })
 end
-docSpecial('local', {'name', 'val'},
-           'Introduce new top-level immutable local.')
+docSpecial("local", {"name", "val"},
+           "Introduce new top-level immutable local.")
 
-SPECIALS['var'] = function(ast, scope, parent)
+SPECIALS["var"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         declaration = true,
@@ -1508,16 +1592,16 @@ SPECIALS['var'] = function(ast, scope, parent)
         isvar = true
     })
 end
-docSpecial('var', {'name', 'val'},
-           'Introduce new mutable local.')
+docSpecial("var", {"name", "val"},
+           "Introduce new mutable local.")
 
-SPECIALS['let'] = function(ast, scope, parent, opts)
+SPECIALS["let"] = function(ast, scope, parent, opts)
     local bindings = ast[2]
     assertCompile(isList(bindings) or isTable(bindings),
-                  'expected table for destructuring', ast)
+                  "expected table for destructuring", ast)
     assertCompile(#bindings % 2 == 0,
-                  'expected even number of name/value bindings', ast)
-    assertCompile(#ast >= 3, 'missing body expression', ast)
+                  "expected even number of name/value bindings", ast)
+    assertCompile(#ast >= 3, "missing body expression", ast)
     local subScope = makeScope(scope)
     local subChunk = {}
     for i = 1, #bindings, 2 do
@@ -1528,12 +1612,12 @@ SPECIALS['let'] = function(ast, scope, parent, opts)
     end
     return doImpl(ast, scope, parent, opts, 3, subChunk, subScope)
 end
-docSpecial('let', {'[name1 val1 ... nameN valN]', '...'},
-           'Introduces a new scope in which a given set of local bindings are used.')
+docSpecial("let", {"[name1 val1 ... nameN valN]", "..."},
+           "Introduces a new scope in which a given set of local bindings are used.")
 
 -- For setting items in a table
-SPECIALS['tset'] = function(ast, scope, parent)
-    assertCompile(#ast > 3, ('tset form needs table, key, and value'), ast)
+SPECIALS["tset"] = function(ast, scope, parent)
+    assertCompile(#ast > 3, ("tset form needs table, key, and value"), ast)
     local root = compile1(ast[2], scope, parent, {nval = 1})[1]
     local keys = {}
     for i = 3, #ast - 1 do
@@ -1543,17 +1627,18 @@ SPECIALS['tset'] = function(ast, scope, parent)
     local value = compile1(ast[#ast], scope, parent, {nval = 1})[1]
     local rootstr = tostring(root)
     -- Prefix 'do end ' so parens are not ambiguous (grouping or function call?)
-    local fmtstr = (rootstr:match('^{')) and 'do end (%s)[%s] = %s' or '%s[%s] = %s'
+    local fmtstr = (rootstr:match("^{")) and "do end (%s)[%s] = %s" or "%s[%s] = %s"
     emit(parent, fmtstr:format(tostring(root),
                                table.concat(keys, ']['),
                                tostring(value)), ast)
 end
-docSpecial('tset', {'tbl', 'key1', 'val1', '...', 'keyN', 'valN'},
-           'Set the fields of a table to new values. Takes 1 or more key/value pairs.')
+docSpecial("tset", {"tbl", "key1", "...", "keyN", "val"},
+           "Set the value of a table field. Can take additional keys to set"
+        .. "nested values,\nbut all parents must contain an existing table.")
 
 -- The if special form behaves like the cond form in
 -- many languages
-SPECIALS['if'] = function(ast, scope, parent, opts)
+SPECIALS["if"] = function(ast, scope, parent, opts)
     local doScope = makeScope(scope)
     local branches = {}
     local elseBranch = nil
@@ -1635,6 +1720,10 @@ SPECIALS['if'] = function(ast, scope, parent, opts)
             if hasElse then
                 emit(lastBuffer, 'else', ast)
                 emit(lastBuffer, elseBranch.chunk, ast)
+            -- TODO: Consolidate use of condLine ~= "else" with hasElse
+            elseif(innerTarget and condLine ~= 'else') then
+                emit(lastBuffer, 'else', ast)
+                emit(lastBuffer, ("%s = nil"):format(innerTarget), ast)
             end
             emit(lastBuffer, 'end', ast)
         elseif not branches[i + 1].nested then
@@ -1666,60 +1755,63 @@ SPECIALS['if'] = function(ast, scope, parent, opts)
         return targetExprs
     end
 end
-docSpecial('if', {'cond1', 'body1', '...', 'condN', 'bodyN'},
-           'Conditional form.\n' ..
-               'Takes any number of condition/body pairs and evaluates the first body where'
-               .. '\nthe condition evaluates to truthy. Similar to cond in other lisps.')
+docSpecial("if", {"cond1", "body1", "...", "condN", "bodyN"},
+           "Conditional form.\n" ..
+               "Takes any number of condition/body pairs and evaluates the first body where"
+               .. "\nthe condition evaluates to truthy. Similar to cond in other lisps.")
 
 -- (each [k v (pairs t)] body...) => []
-SPECIALS['each'] = function(ast, scope, parent)
-    local binding = assertCompile(isTable(ast[2]), 'expected binding table', ast)
+SPECIALS["each"] = function(ast, scope, parent)
+    local binding = assertCompile(isTable(ast[2]), "expected binding table", ast)
     local iter = table.remove(binding, #binding) -- last item is iterator call
-    local bindVars = {}
     local destructures = {}
-    for _, v in ipairs(binding) do
-        assertCompile(isSym(v) or isTable(v),
-                      'expected iterator symbol or table', ast)
-        if(isSym(v)) then
-            table.insert(bindVars, declareLocal(v, {}, scope, ast))
+    local newManglings = {}
+    local function destructureBinding(v)
+        assertCompile(isSym(v) or isTable(v), "expected iterator symbol or table", ast)
+        if isSym(v) then
+            return declareLocal(v, {}, scope, ast, newManglings)
         else
             local raw = sym(gensym(scope))
             destructures[raw] = v
-            table.insert(bindVars, declareLocal(raw, {}, scope, ast))
+            return declareLocal(raw, {}, scope, ast)
         end
     end
-    emit(parent, ('for %s in %s do'):format(
-             table.concat(bindVars, ', '),
-             tostring(compile1(iter, scope, parent, {nval = 1})[1])), ast)
+    local bindVars = map(binding, destructureBinding)
+    local vals = compile1(iter, scope, parent)
+    local valNames = map(vals, tostring)
+
+    emit(parent, ('for %s in %s do'):format(table.concat(bindVars, ', '),
+                                            table.concat(valNames, ", ")), ast)
     local chunk = {}
     for raw, args in pairs(destructures) do
         destructure(args, raw, ast, scope, chunk,
                     { declaration = true, nomulti = true })
     end
+    applyManglings(scope, newManglings, ast)
     compileDo(ast, scope, chunk, 3)
     emit(parent, chunk, ast)
     emit(parent, 'end', ast)
 end
-docSpecial('each', {'[key value (iterator)]', '...'},
-           'Runs the body once for each set of values provided by the given iterator.'
-           ..'\nMost commonly used with ipairs for sequential tables or pairs for'
-               ..' undefined\norder, but can be used with any iterator.')
+docSpecial("each", {"[key value (iterator)]", "..."},
+           "Runs the body once for each set of values provided by the given iterator."
+           .."\nMost commonly used with ipairs for sequential tables or pairs for"
+               .." undefined\norder, but can be used with any iterator.")
 
 -- (while condition body...) => []
-SPECIALS['while'] = function(ast, scope, parent)
+SPECIALS["while"] = function(ast, scope, parent)
     local len1 = #parent
     local condition = compile1(ast[2], scope, parent, {nval = 1})[1]
     local len2 = #parent
     local subChunk = {}
     if len1 ~= len2 then
         -- Compound condition
-        emit(parent, 'while true do', ast)
         -- Move new compilation to subchunk
         for i = len1 + 1, len2 do
             subChunk[#subChunk + 1] = parent[i]
             parent[i] = nil
         end
-        emit(parent, ('if %s then break end'):format(condition[1]), ast)
+        emit(parent, 'while true do', ast)
+        emit(subChunk, ('if not %s then break end'):format(condition[1]), ast)
     else
         -- Simple condition
         emit(parent, 'while ' .. tostring(condition) .. ' do', ast)
@@ -1728,13 +1820,13 @@ SPECIALS['while'] = function(ast, scope, parent)
     emit(parent, subChunk, ast)
     emit(parent, 'end', ast)
 end
-docSpecial('while', {'condition', '...'},
-           'The classic while loop. Evaluates body until a condition is non-truthy.')
+docSpecial("while", {"condition", "..."},
+           "The classic while loop. Evaluates body until a condition is non-truthy.")
 
-SPECIALS['for'] = function(ast, scope, parent)
-    local ranges = assertCompile(isTable(ast[2]), 'expected binding table', ast)
+SPECIALS["for"] = function(ast, scope, parent)
+    local ranges = assertCompile(isTable(ast[2]), "expected binding table", ast)
     local bindingSym = assertCompile(isSym(table.remove(ast[2], 1)),
-                                     'expected iterator symbol', ast)
+                                     "expected iterator symbol", ast)
     local rangeArgs = {}
     for i = 1, math.min(#ranges, 3) do
         rangeArgs[i] = tostring(compile1(ranges[i], scope, parent, {nval = 1})[1])
@@ -1747,11 +1839,11 @@ SPECIALS['for'] = function(ast, scope, parent)
     emit(parent, chunk, ast)
     emit(parent, 'end', ast)
 end
-docSpecial('for', {'[index start stop step?]', '...'}, 'Numeric loop construct.' ..
-               '\nEvaluates body once for each value between start and stop (inclusive).')
+docSpecial("for", {"[index start stop step?]", "..."}, "Numeric loop construct." ..
+               "\nEvaluates body once for each value between start and stop (inclusive).")
 
-SPECIALS[':'] = function(ast, scope, parent)
-    assertCompile(#ast >= 3, 'expected at least 3 arguments', ast)
+SPECIALS[":"] = function(ast, scope, parent)
+    assertCompile(#ast >= 3, "expected at least 3 arguments", ast)
     -- Compile object
     local objectexpr = compile1(ast[2], scope, parent, {nval = 1})[1]
     -- Compile method selector
@@ -1770,9 +1862,7 @@ SPECIALS[':'] = function(ast, scope, parent)
         local subexprs = compile1(ast[i], scope, parent, {
             nval = i ~= #ast and 1 or nil
         })
-        for j = 1, #subexprs do
-            args[#args + 1] = tostring(subexprs[j])
-        end
+        map(subexprs, tostring, args)
     end
     local fstring
     if not methodident then
@@ -1791,21 +1881,21 @@ SPECIALS[':'] = function(ast, scope, parent)
         methodstring,
         table.concat(args, ', ')), 'statement')
 end
-docSpecial(':', {'tbl', 'method-name', '...'},
-           'Call the named method on tbl with the provided args.'..
-           '\nMethod name doesn\'t have to be known at compile-time; if it is, use'
-               ..'\n(tbl:method-name ...) instead.')
+docSpecial(":", {"tbl", "method-name", "..."},
+           "Call the named method on tbl with the provided args."..
+           "\nMethod name doesn\"t have to be known at compile-time; if it is, use"
+               .."\n(tbl:method-name ...) instead.")
 
-SPECIALS['comment'] = function(ast, _, parent)
+SPECIALS["comment"] = function(ast, _, parent)
     local els = {}
     for i = 2, #ast do
         els[#els + 1] = tostring(ast[i]):gsub('\n', ' ')
     end
     emit(parent, '              -- ' .. table.concat(els, ' '), ast)
 end
-docSpecial('comment', {'...'}, 'Comment which will be emitted in Lua output.')
+docSpecial("comment", {"..."}, "Comment which will be emitted in Lua output.")
 
-SPECIALS['hashfn'] = function(ast, scope, parent)
+SPECIALS["hashfn"] = function(ast, scope, parent)
     assertCompile(#ast == 2, "expected one argument", ast)
     local fScope = makeScope(scope)
     local fChunk = {}
@@ -1826,7 +1916,7 @@ SPECIALS['hashfn'] = function(ast, scope, parent)
     emit(parent, 'end', ast)
     return expr(name, 'sym')
 end
-docSpecial('hashfn', {'...'}, 'Function literal shorthand; args are $1, $2, etc.')
+docSpecial("hashfn", {"..."}, "Function literal shorthand; args are $1, $2, etc.")
 
 local function defineArithmeticSpecial(name, zeroArity, unaryPrefix)
     local paddedOp = ' ' .. name .. ' '
@@ -1841,9 +1931,7 @@ local function defineArithmeticSpecial(name, zeroArity, unaryPrefix)
                 local subexprs = compile1(ast[i], scope, parent, {
                     nval = (i == 1 and 1 or nil)
                 })
-                for j = 1, #subexprs do
-                    operands[#operands + 1] = tostring(subexprs[j])
-                end
+                map(subexprs, tostring, operands)
             end
             if #operands == 1 then
                 if unaryPrefix then
@@ -1856,8 +1944,8 @@ local function defineArithmeticSpecial(name, zeroArity, unaryPrefix)
             end
         end
     end
-    docSpecial(name, {'a', 'b', '...'},
-               'Arithmetic operator; works the same as Lua but accepts more arguments.')
+    docSpecial(name, {"a", "b", "..."},
+               "Arithmetic operator; works the same as Lua but accepts more arguments.")
 end
 
 defineArithmeticSpecial('+', '0')
@@ -1871,18 +1959,18 @@ defineArithmeticSpecial('//', nil, '1')
 defineArithmeticSpecial('or', 'false')
 defineArithmeticSpecial('and', 'true')
 
-docSpecial('and', {'a', 'b', '...'},
-           'Boolean operator; works the same as Lua but accepts more arguments.')
-docSpecial('or', {'a', 'b', '...'},
-           'Boolean operator; works the same as Lua but accepts more arguments.')
-docSpecial('..', {'a', 'b', '...'},
-           'String concatenation operator; works the same as Lua but accepts more arguments.')
+docSpecial("and", {"a", "b", "..."},
+           "Boolean operator; works the same as Lua but accepts more arguments.")
+docSpecial("or", {"a", "b", "..."},
+           "Boolean operator; works the same as Lua but accepts more arguments.")
+docSpecial("..", {"a", "b", "..."},
+           "String concatenation operator; works the same as Lua but accepts more arguments.")
 
 local function defineComparatorSpecial(name, realop, chainOp)
     local op = realop or name
     SPECIALS[name] = function(ast, scope, parent)
         local len = #ast
-        assertCompile(len > 2, 'expected at least two arguments', ast)
+        assertCompile(len > 2, "expected at least two arguments", ast)
         local lhs = compile1(ast[2], scope, parent, {nval = 1})[1]
         local lastval = compile1(ast[3], scope, parent, {nval = 1})[1]
         -- avoid double-eval by introducing locals for possible side-effects
@@ -1901,8 +1989,8 @@ local function defineComparatorSpecial(name, realop, chainOp)
         end
         return out
     end
-    docSpecial(name, {name, 'a', 'b', '...'},
-               'Comparison operator; works the same as Lua but accepts more arguments.')
+    docSpecial(name, {"a", "b", "..."},
+               "Comparison operator; works the same as Lua but accepts more arguments.")
 end
 
 defineComparatorSpecial('>')
@@ -1921,12 +2009,12 @@ local function defineUnarySpecial(op, realop)
     end
 end
 
-defineUnarySpecial('not', 'not ')
-docSpecial('not', {'x'}, 'Boolean operator; works the same as Lua.')
+defineUnarySpecial("not", "not ")
+docSpecial("not", {"x"}, "Logical operator; works the same as Lua.")
 
-defineUnarySpecial('length', '#')
-docSpecial('length', {'x'}, 'Returns the length of a table or string.')
-SPECIALS['#'] = SPECIALS['length']
+defineUnarySpecial("length", "#")
+docSpecial("length", {"x"}, "Returns the length of a table or string.")
+SPECIALS["#"] = SPECIALS["length"]
 
 -- Save current macro scope
 local macroCurrentScope = GLOBAL_SCOPE
@@ -1951,38 +2039,20 @@ end
 
 local requireSpecial
 local function compile(ast, options)
-    options = options or {}
+    local opts = copy(options)
     local oldGlobals = allowedGlobals
-    local oldChunk = rootChunk
-    local oldScope = rootScope
-    local oldOptions = rootOptions
-    allowedGlobals = options.allowedGlobals
-    if options.indent == nil then options.indent = '  ' end
+    setResetRoot(rootChunk, rootScope, rootOptions)
+    allowedGlobals = opts.allowedGlobals
+    if opts.indent == nil then opts.indent = '  ' end
     local chunk = {}
-    local scope = options.scope or makeScope(GLOBAL_SCOPE)
-    rootChunk = chunk
-    rootScope = scope
-    rootOptions = options
-    if options.requireAsInclude then scope.specials.require = requireSpecial end
+    local scope = opts.scope or makeScope(GLOBAL_SCOPE)
+    rootChunk, rootScope, rootOptions = chunk, scope, opts
+    if opts.requireAsInclude then scope.specials.require = requireSpecial end
     local exprs = compile1(ast, scope, chunk, {tail = true})
     keepSideEffects(exprs, chunk, nil, ast)
     allowedGlobals = oldGlobals
-    rootChunk = oldChunk
-    rootScope = oldScope
-    rootOptions = oldOptions
-    return flatten(chunk, options)
-end
-
--- map a function across all pairs in a table
-local function quoteTmap(f, t)
-    local res = {}
-    for k,v in pairs(t) do
-        local nk, nv = f(k, v)
-        if nk then
-            res[nk] = nv
-        end
-    end
-    return res
+    resetRoot()
+    return flatten(chunk, opts)
 end
 
 -- make a transformer for key / value table pairs, preserving all numeric keys
@@ -2040,11 +2110,11 @@ local function doQuote (form, scope, parent, runtime)
     -- list
     elseif isList(form) then
         assertCompile(not runtime, "lists may only be used at compile time", form)
-        local mapped = quoteTmap(entryTransform(no, q), form)
+        local mapped = kvmap(form, entryTransform(no, q))
         return 'list(' .. mixedConcat(mapped, ", ") .. ')'
     -- table
     elseif type(form) == 'table' then
-        local mapped = quoteTmap(entryTransform(q, q), form)
+        local mapped = kvmap(form, entryTransform(q, q))
         return '{' .. mixedConcat(mapped, ", ") .. '}'
     -- string
     elseif type(form) == 'string' then
@@ -2066,24 +2136,20 @@ end
 docSpecial('quote', {'x'}, 'Quasiquote the following form. Only works in macro/compiler scope.')
 
 local function compileStream(strm, options)
-    options = options or {}
+    local opts = copy(options)
     local oldGlobals = allowedGlobals
-    local oldChunk = rootChunk
-    local oldScope = rootScope
-    local oldOptions = rootOptions
-    allowedGlobals = options.allowedGlobals
-    if options.indent == nil then options.indent = '  ' end
-    local scope = options.scope or makeScope(GLOBAL_SCOPE)
-    if options.requireAsInclude then scope.specials.require = requireSpecial end
+    setResetRoot(rootChunk, rootScope, rootOptions)
+    allowedGlobals = opts.allowedGlobals
+    if opts.indent == nil then opts.indent = '  ' end
+    local scope = opts.scope or makeScope(GLOBAL_SCOPE)
+    if opts.requireAsInclude then scope.specials.require = requireSpecial end
     local vals = {}
-    for ok, val in parser(strm, options.filename) do
+    for ok, val in parser(strm, opts.filename) do
         if not ok then break end
         vals[#vals + 1] = val
     end
     local chunk = {}
-    rootChunk = chunk
-    rootScope = scope
-    rootOptions = options
+    rootChunk, rootScope, rootOptions = chunk, scope, opts
     for i = 1, #vals do
         local exprs = compile1(vals[i], scope, chunk, {
             tail = i == #vals,
@@ -2091,10 +2157,8 @@ local function compileStream(strm, options)
         keepSideEffects(exprs, chunk, nil, vals[i])
     end
     allowedGlobals = oldGlobals
-    rootChunk = oldChunk
-    rootScope = oldScope
-    rootOptions = oldOptions
-    return flatten(chunk, options)
+    resetRoot()
+    return flatten(chunk, opts)
 end
 
 local function compileString(str, options)
@@ -2127,14 +2191,10 @@ local function wrapEnv(env)
         -- checking the __pairs metamethod won't work automatically in Lua 5.1
         -- sadly, but it's important for 5.2+ and can be done manually in 5.1
         __pairs = function()
-            local pt = {}
-            for key, value in pairs(env) do
-                if type(key) == 'string' then
-                    pt[globalUnmangling(key)] = value
-                else
-                    pt[key] = value
-                end
+            local function putenv(k, v)
+                return type(k) == 'string' and globalUnmangling(k) or k, v
             end
+            local pt = kvmap(env, putenv)
             return next, pt, nil
         end,
     })
@@ -2147,8 +2207,12 @@ local function traceback(msg, start)
     local level = start or 2 -- Can be used to skip some frames
     local lines = {}
     if msg then
-        local stripped = msg:gsub('^[^:]*:%d+:%s+', 'runtime error: ')
-        table.insert(lines, stripped)
+        if msg:find("^Compile error") then
+            table.insert(lines, msg)
+        else
+            local newmsg = msg:gsub('^[^:]*:%d+:%s+', 'runtime error: ')
+            table.insert(lines, newmsg)
+        end
     end
     table.insert(lines, 'stack traceback:')
     while true do
@@ -2187,212 +2251,44 @@ local function traceback(msg, start)
 end
 
 local function currentGlobalNames(env)
-    local names = {}
-    for k in pairs(env or _G) do
-       k = globalUnmangling(k)
-       table.insert(names, k)
-    end
-    return names
+    return kvmap(env or _G, globalUnmangling)
 end
 
 local function eval(str, options, ...)
-    options = options or {}
+    local opts = copy(options)
     -- eval and dofile are considered "live" entry points, so we can assume
     -- that the globals available at compile time are a reasonable allowed list
     -- UNLESS there's a metatable on env, in which case we can't assume that
     -- pairs will return all the effective globals; for instance openresty
     -- sets up _G in such a way that all the globals are available thru
     -- the __index meta method, but as far as pairs is concerned it's empty.
-    if options.allowedGlobals == nil and not getmetatable(options.env) then
-        options.allowedGlobals = currentGlobalNames(options.env)
+    if opts.allowedGlobals == nil and not getmetatable(opts.env) then
+        opts.allowedGlobals = currentGlobalNames(opts.env)
     end
-    local env = options.env and wrapEnv(options.env)
-    local luaSource = compileString(str, options)
+    local env = opts.env and wrapEnv(opts.env)
+    local luaSource = compileString(str, opts)
     local loader = loadCode(luaSource, env,
-        options.filename and ('@' .. options.filename) or str)
+                            opts.filename and ('@' .. opts.filename) or str)
+    opts.filename = nil
     return loader(...)
 end
 
 local function dofileFennel(filename, options, ...)
-    options = options or {}
-    if options.allowedGlobals == nil then
-        options.allowedGlobals = currentGlobalNames(options.env)
+    local opts = copy(options)
+    if opts.allowedGlobals == nil then
+        opts.allowedGlobals = currentGlobalNames(opts.env)
     end
     local f = assert(io.open(filename, "rb"))
     local source = f:read("*all"):gsub("^#![^\n]*\n", "")
     f:close()
-    options.filename = options.filename or filename
-    return eval(source, options, ...)
-end
-
--- Implements a configurable repl
-local function repl(options)
-
-    local opts = options or {}
-    -- This would get set for us when calling eval, but we want to seed it
-    -- with a value that is persistent so it doesn't get reset on each eval.
-    if opts.allowedGlobals == nil then
-        opts.allowedGlobals = currentGlobalNames(opts.env)
-    end
-
-    opts.useMetadata = options.useMetadata ~= false
-    opts.moduleName = options.moduleName
-    rootOptions = opts
-
-    local env = opts.env and wrapEnv(opts.env) or setmetatable({}, {
-        __index = _ENV or _G
-    })
-
-    local function defaultReadChunk(parserState)
-        io.write(parserState.stackSize > 0 and '.. ' or '>> ')
-        io.flush()
-        local input = io.read()
-        return input and input .. '\n'
-    end
-
-    local function defaultOnValues(xs)
-        io.write(table.concat(xs, '\t'))
-        io.write('\n')
-    end
-
-    local function defaultOnError(errtype, err, luaSource)
-        if (errtype == 'Lua Compile') then
-            io.write('Bad code generated - likely a bug with the compiler:\n')
-            io.write('--- Generated Lua Start ---\n')
-            io.write(luaSource .. '\n')
-            io.write('--- Generated Lua End ---\n')
-        end
-        if (errtype == 'Runtime') then
-            io.write(traceback(err, 4))
-            io.write('\n')
-        else
-            io.write(('%s error: %s\n'):format(errtype, tostring(err)))
-        end
-    end
-
-    local envdbg = (opts.env or _G)["debug"]
-    -- if the environment doesn't support debug.getlocal you can't save locals
-    local saveLocals = opts.saveLocals ~= false and envdbg and envdbg.getlocal
-    local saveSource = table.
-       concat({"local ___i___ = 1",
-               "while true do",
-               " local name, value = debug.getlocal(1, ___i___)",
-               " if(name and name ~= \"___i___\") then",
-               " ___replLocals___[name] = value",
-               " ___i___ = ___i___ + 1",
-               " else break end end"}, "\n")
-
-    -- we do some source munging in order to save off locals from each chunk
-    -- and reintroduce them to the beginning of the next chunk, allowing
-    -- locals to work in the repl the way you'd expect them to.
-       local spliceSaveLocals = function(luaSource)
-        env.___replLocals___ = env.___replLocals___ or {}
-        local splicedSource = {}
-        for line in luaSource:gmatch("([^\n]+)\n?") do
-            table.insert(splicedSource, line)
-        end
-        -- reintroduce locals from the previous time around
-        local bind = "local %s = ___replLocals___['%s']"
-        for name in pairs(env.___replLocals___) do
-            table.insert(splicedSource, 1, bind:format(name, name))
-        end
-        -- save off new locals at the end - if safe to do so (i.e. last line is a return)
-        if (string.match(splicedSource[#splicedSource], "^ *return .*$")) then
-            if (#splicedSource > 1) then
-                table.insert(splicedSource, #splicedSource, saveSource)
-            end
-        end
-        return table.concat(splicedSource, "\n")
-    end
-
-    -- Read options
-    local readChunk = opts.readChunk or defaultReadChunk
-    local onValues = opts.onValues or defaultOnValues
-    local onError = opts.onError or defaultOnError
-    local pp = opts.pp or tostring
-
-    -- Make parser
-    local bytestream, clearstream = granulate(readChunk)
-    local chars = {}
-    local read, reset = parser(function (parserState)
-        local c = bytestream(parserState)
-        chars[#chars + 1] = c
-        return c
-    end)
-
-    local scope = makeScope(GLOBAL_SCOPE)
-
-    local replCompleter = function(text)
-        local matches = {}
-        local inputFragment = text:gsub("[%s)(]*(.+)", "%1")
-
-        -- adds any matching keys from the provided generator/iterator to matches
-        local function addMatchesFromGen(next, param, state)
-          for k in next, param, state do
-            if #matches >= 40 then break -- cap completions at 40 to avoid overwhelming
-            elseif inputFragment == k:sub(0, #inputFragment) then
-                table.insert(matches, k)
-            end
-          end
-        end
-        addMatchesFromGen(pairs(env._ENV or env._G or {}))
-        addMatchesFromGen(pairs(env.___replLocals___ or {}))
-        addMatchesFromGen(pairs(SPECIALS or {}))
-        addMatchesFromGen(pairs(scope.specials or {}))
-        return matches
-    end
-    if opts.registerCompleter then opts.registerCompleter(replCompleter) end
-
-    -- REPL loop
-    while true do
-        chars = {}
-        local ok, parseok, x = pcall(read)
-        local srcstring = string.char(unpack(chars))
-        if not ok then
-            onError('Parse', parseok)
-            clearstream()
-            reset()
-        else
-            if not parseok then break end -- eof
-            local compileOk, luaSource = pcall(compile, x, {
-                correlate = opts.correlate,
-                source = srcstring,
-                scope = scope,
-                useMetadata = opts.useMetadata,
-                moduleName = opts.moduleName,
-            })
-            if not compileOk then
-                clearstream()
-                onError('Compile', luaSource) -- luaSource is error message in this case
-            else
-                if saveLocals then
-                    luaSource = spliceSaveLocals(luaSource)
-                end
-                local luacompileok, loader = pcall(loadCode, luaSource, env)
-                if not luacompileok then
-                    clearstream()
-                    onError('Lua Compile', loader, luaSource)
-                else
-                    local loadok, ret = xpcall(function () return {loader()} end,
-                        function (runtimeErr)
-                            onError('Runtime', runtimeErr)
-                        end)
-                    if loadok then
-                        env._ = ret[1]
-                        env.__ = ret
-                        for i = 1, #ret do ret[i] = pp(ret[i]) end
-                        onValues(ret)
-                    end
-                end
-            end
-        end
-    end
+    opts.filename = filename
+    return eval(source, opts, ...)
 end
 
 local macroLoaded = {}
 
 local pathTable = {"./?.fnl", "./?/init.fnl"}
-local osPath = os.getenv("FENNEL_PATH")
+local osPath = os and os.getenv and os.getenv("FENNEL_PATH")
 if osPath then
     table.insert(pathTable, osPath)
 end
@@ -2405,6 +2301,7 @@ local module = {
     compileString = compileString,
     compileStream = compileStream,
     compile1 = compile1,
+    loadCode = loadCode,
     mangle = globalMangling,
     unmangle = globalUnmangling,
     list = list,
@@ -2413,14 +2310,166 @@ local module = {
     scope = makeScope,
     gensym = gensym,
     eval = eval,
-    repl = repl,
     dofile = dofileFennel,
     macroLoaded = macroLoaded,
     path = table.concat(pathTable, ";"),
     traceback = traceback,
-    version = "0.3.0",
+    version = "0.4.0-dev",
 }
 
+-- In order to make this more readable, you can switch your editor to treating
+-- this file as if it were Fennel for the purposes of this section
+local replsource = [===[(local (fennel internals) ...)
+
+(fn default-read-chunk [parser-state]
+  (io.write (if (< 0 parser-state.stackSize) ".." ">> "))
+  (io.flush)
+  (let [input (io.read)]
+    (and input (.. input "\n"))))
+
+(fn default-on-values [xs]
+  (io.write (table.concat xs "\t"))
+  (io.write "\n"))
+
+(fn default-on-error [errtype err lua-source]
+  (io.write
+   (match errtype
+     "Lua Compile" (.. "Bad code generated - likely a bug with the compiler:\n"
+                       "--- Generated Lua Start ---\n"
+                       lua-source
+                       "--- Generated Lua End ---\n")
+     "Runtime" (.. (fennel.traceback err 4) "\n")
+     _ (: "%s error: %s\n" :format errtype (tostring err)))))
+
+(local save-source
+       (table.concat ["local ___i___ = 1"
+                      "while true do"
+                      " local name, value = debug.getlocal(1, ___i___)"
+                      " if(name and name ~= \"___i___\") then"
+                      " ___replLocals___[name] = value"
+                      " ___i___ = ___i___ + 1"
+                      " else break end end"] "\n"))
+
+(fn splice-save-locals [env lua-source]
+  (set env.___replLocals___ (or env.___replLocals___ {}))
+  (let [spliced-source []
+        bind "local %s = ___replLocals___['%s']"]
+    (each [line (lua-source:gmatch "([^\n]+)\n?")]
+      (table.insert spliced-source line))
+    (each [name (pairs env.___replLocals___)]
+      (table.insert spliced-source 1 (bind:format name name)))
+    (when (and (: (. spliced-source (# spliced-source)) :match "^ *return .*$")
+               (< 1 (# spliced-source)))
+      (table.insert spliced-source (# spliced-source) save-source))
+    (table.concat spliced-source "\n")))
+
+(fn completer [env scope text]
+  (let [matches []
+        input-fragment (text:gsub ".*[%s)(]+" "")]
+    (fn add-partials [input tbl prefix] ; add partial key matches in tbl
+      (each [k (pairs tbl)]
+        (let [k (if (or (= tbl env) (= tbl env.___replLocals___))
+                    (. scope.unmanglings k)
+                    k)]
+          (when (and (< (# matches) 40)
+                     (= (type k) "string")
+                     (= input (k:sub 0 (# input))))
+            (table.insert matches (.. prefix k))))))
+    (fn add-matches [input tbl prefix] ; add matches, descending into tbl fields
+      (let [prefix (if prefix (.. prefix ".") "")]
+        (if (not (input:find "%.")) ; no more dots, so add matches
+            (add-partials input tbl prefix)
+            (let [(head tail) (input:match "^([^.]+)%.(.*)")
+                  raw-head (if (or (= tbl env) (= tbl env.___replLocals___))
+                               (. scope.manglings head)
+                               head)]
+              (when (= (type (. tbl raw-head)) "table")
+                (add-matches tail (. tbl raw-head) (.. prefix head)))))))
+
+    (add-matches input-fragment (or scope.specials []))
+    (add-matches input-fragment (or internals.SPECIALS []))
+    (add-matches input-fragment (or env.___replLocals___ []))
+    (add-matches input-fragment env)
+    (add-matches input-fragment (or env._ENV env._G []))
+    matches))
+
+(fn repl [options]
+  (let [old-root-options internals.rootOptions
+        env (if options.env
+                (internals.wrapEnv options.env)
+                (setmetatable {} {:__index (or _G._ENV _G)}))
+        save-locals? (and (not= options.saveLocals false)
+                          env.debug env.debug.getlocal)
+        opts {}
+        _ (each [k v (pairs options)] (tset opts k v))
+        read-chunk (or opts.readChunk default-read-chunk)
+        on-values (or opts.onValues default-on-values)
+        on-error (or opts.onError default-on-error)
+        pp (or opts.pp tostring)
+        ;; make parser
+        (byte-stream clear-stream) (fennel.granulate read-chunk)
+        chars []
+        (read reset) (fennel.parser (fn [parser-state]
+                                      (let [c (byte-stream parser-state)]
+                                        (tset chars (+ (# chars) 1) c)
+                                        c)))
+        scope (fennel.scope)]
+
+    ;; use metadata unless we've specifically disabled it
+    (set opts.useMetadata (not= options.useMetadata false))
+    (when (= opts.allowedGlobals nil)
+      (set opts.allowedGlobals (internals.currentGlobalNames opts.env)))
+
+    (when opts.registerCompleter
+      (opts.registerCompleter (partial completer env scope)))
+
+    (fn loop []
+      (each [k (pairs chars)] (tset chars k nil))
+      (let [(ok parse-ok? x) (pcall read)
+            src-string (string.char ((or _G.unpack table.unpack) chars))]
+        (internals.setRootOptions opts)
+        (if (not ok)
+            (do (on-error "Parse" parse-ok?)
+                (clear-stream)
+                (reset)
+                (loop))
+            (when parse-ok? ; if this is false, we got eof
+              (match (pcall fennel.compile x {:correlate opts.correlate
+                                              :source src-string
+                                              :scope scope
+                                              :useMetadata opts.useMetadata
+                                              :moduleName opts.moduleName})
+                (false msg) (do (clear-stream)
+                                (on-error "Compile" msg))
+                (true source) (let [source (if save-locals?
+                                               (splice-save-locals env source)
+                                               source)
+                                    (lua-ok? loader) (pcall fennel.loadCode
+                                                            source env)]
+                                (if (not lua-ok?)
+                                    (do (clear-stream)
+                                        (on-error "Lua Compile" loader source))
+                                    (match (xpcall #[(loader)]
+                                                   (partial on-error "Runtime"))
+                                      (true ret)
+                                      (do (set env._ (. ret 1))
+                                          (set env.__ ret)
+                                          (on-values (internals.map ret pp)))))))
+              (internals.setRootOptions old-root-options)
+              (loop)))))
+    (loop)))]===]
+
+module.repl = function(options)
+    -- functionality the repl needs that isn't part of the public API yet
+    local internals = { rootOptions = rootOptions,
+                        setRootOptions = function(r) rootOptions = r end,
+                        currentGlobalNames = currentGlobalNames,
+                        wrapEnv = wrapEnv,
+                        SPECIALS = SPECIALS,
+                        map = map }
+    return eval(replsource, { correlate = true }, module, internals)(options)
+end
+
 local function searchModule(modulename, pathstring)
     modulename = modulename:gsub("%.", "/")
     for path in string.gmatch((pathstring or module.path)..";", "([^;]*);") do
@@ -2438,8 +2487,7 @@ module.makeSearcher = function(options)
       -- this will propagate options from the repl but not from eval, because
       -- eval unsets rootOptions after compiling but before running the actual
       -- calls to require.
-      local opts = {}
-      for k,v in pairs(rootOptions or {}) do opts[k] = v end
+      local opts = copy(rootOptions)
       for k,v in pairs(options or {}) do opts[k] = v end
       local filename = searchModule(modulename)
       if filename then
@@ -2490,24 +2538,14 @@ local function makeCompilerEnv(ast, scope, parent)
 end
 
 local function macroGlobals(env, globals)
-    local allowed = {}
-    for k in pairs(env) do
-        local g = globalUnmangling(k)
-        table.insert(allowed, g)
-    end
-    if globals then
-        for _, k in pairs(globals) do
-            table.insert(allowed, k)
-        end
-    end
+    local allowed = currentGlobalNames(env)
+    for _, k in pairs(globals or {}) do table.insert(allowed, k) end
     return allowed
 end
 
 local function addMacros(macros, ast, scope)
     assertCompile(isTable(macros), 'expected macros to be table', ast)
-    for k, v in pairs(macros) do
-        scope.specials[k] = macroToSpecial(v)
-    end
+    kvmap(macros, function(k, v) return k, macroToSpecial(v) end, scope.specials)
 end
 
 local function loadMacros(modname, ast, scope, parent)
@@ -2548,10 +2586,7 @@ SPECIALS['include'] = function(ast, scope, parent, opts)
     local mod = loadCode(code)()
 
     -- Check cache
-    local includeExpr = scope.includes[mod]
-    if includeExpr then
-        return includeExpr
-    end
+    if scope.includes[mod] then return scope.includes[mod] end
 
     -- Find path to source
     local path = searchModule(mod)
@@ -2573,32 +2608,45 @@ SPECIALS['include'] = function(ast, scope, parent, opts)
     local s = f:read('*all')
     f:close()
 
-    -- splice in source and memoize it
-    -- so we can include it again without duplication
-    local target = gensym(scope)
-    local ret = expr(target, 'sym')
+    -- splice in source and memoize it in compiler AND package.preload
+    -- so we can include it again without duplication, even in runtime
+    local target = 'package.preload["' .. mod .. '"]'
+    local ret = expr('require("' .. mod .. '")', 'statement')
+
+    local subChunk, tempChunk = {}, {}
+    emit(tempChunk, subChunk, ast)
+    -- if lua, simply emit the setting of package.preload
+    if not isFennel then
+        emit(tempChunk, target .. ' = ' .. target .. ' or function()\n' .. s .. 'end', ast)
+    end
+    -- Splice tempChunk to begining of rootChunk
+    for i, v in ipairs(tempChunk) do
+        table.insert(rootChunk, i, v)
+    end
+
+    -- For fnl source, compile subChunk AFTER splicing into start of rootChunk.
     if isFennel then
-        local p = parser(stringStream(s), path)
-        local forms = list(sym('do'))
-        for _, val in p do table.insert(forms, val) end
+        local subopts = { nval = 1, target = target }
         local subscope = makeScope(rootScope.parent)
         if rootOptions.requireAsInclude then
             subscope.specials.require = requireSpecial
         end
-        local subopts = {
-            nval = 1,
-            target = target
-        }
-        emit(rootChunk, 'local ' .. target, ast)
-        compile1(forms, subscope, rootChunk, subopts)
-    else
-        emit(rootChunk, 'local ' .. target .. ' = (function() ' .. s .. ' end)()', ast)
+        local targetForm = list(sym('.'), sym('package.preload'), mod)
+        -- splice "or" statement in so it uses existing package.preload[modname]
+        -- if it's been set by something else, allowing for overrides
+        local forms = list(sym('or'), targetForm, list(sym('fn'), sequence()))
+        local p = parser(stringStream(s), path)
+        for _, val in p do table.insert(forms[3], val) end
+        compile1(forms, subscope, subChunk, subopts)
     end
 
     -- Put in cache and return
     rootScope.includes[mod] = ret
     return ret
 end
+docSpecial('include', {'module-name-literal'},
+           'Like require, but load the target module during compilation and embed it in the\n'
+        .. 'Lua output. The module must be a string literal and resolvable at compile time.')
 
 local function requireFallback(e)
     local code = ('require(%s)'):format(tostring(e))
@@ -2795,7 +2843,7 @@ that argument name begins with ?."
                   (do (assert (not (. pattern (+ k 2)))
                               "expected rest argument in final position")
                       (table.insert bindings (. pattern (+ k 1)))
-                      (table.insert bindings [`(select ,k ((or unpack table.unpack)
+                      (table.insert bindings [`(select ,k ((or _G.unpack table.unpack)
                                                            ,val))]))
                   (and (= :number (type k))
                        (= "&" (tostring (. pattern (- k 1)))))
@@ -2846,19 +2894,21 @@ do
     local moduleName = "__fennel-bootstrap__"
     package.preload[moduleName] = function() return module end
     local env = makeCompilerEnv(nil, COMPILER_SCOPE, {})
-    for name, fn in pairs(eval(stdmacros, {
-        env = env,
-        scope = makeScope(COMPILER_SCOPE),
-        -- assume the code to load globals doesn't have any mistaken globals,
-        -- otherwise this can be problematic when loading fennel in contexts
-        -- where _G is an empty table with an __index metamethod. (openresty)
-        allowedGlobals = false,
-        useMetadata = true,
-        filename = "built-ins",
-        moduleName = moduleName,
-    })) do
-        SPECIALS[name] = macroToSpecial(fn, name)
-    end
+    local macros = eval(stdmacros, {
+                            env = env,
+                            scope = makeScope(COMPILER_SCOPE),
+                            -- assume the code to load globals doesn't have any
+                            -- mistaken globals, otherwise this can be
+                            -- problematic when loading fennel in contexts
+                            -- where _G is an empty table with an __index
+                            -- metamethod. (openresty)
+                            allowedGlobals = false,
+                            useMetadata = true,
+                            filename = "built-ins",
+                            moduleName = moduleName })
+    kvmap(macros,
+          function(name, fn) return name, macroToSpecial(fn, name) end,
+          SPECIALS)
     package.preload[moduleName] = nil
 end
 SPECIALS['λ'] = SPECIALS['lambda']
diff --git a/lib/fennel b/lib/fennel
index d1e7f34..e694461 100755
--- a/lib/fennel
+++ b/lib/fennel
@@ -10,8 +10,9 @@ Usage: fennel [FLAG] [FILE]
 
 Run fennel, a lisp programming language for the Lua runtime.
 
-  --repl                  : Launch an interactive repl session
-  --compile FILES         : Compile files and write their Lua to stdout
+  --repl                  : Command to launch an interactive repl session
+  --compile FILES         : Command to compile files and write Lua to stdout
+  --eval SOURCE (-e)      : Command to evaluate source code and print the result
 
   --no-searcher           : Skip installing package.searchers entry
   --indent VAL            : Indent compiler output with VAL
@@ -19,12 +20,13 @@ Run fennel, a lisp programming language for the Lua runtime.
   --add-fennel-path  PATH : Add PATH to fennel.path for finding Fennel modules
   --globals G1[,G2...]    : Allow these globals in addition to standard ones
   --globals-only G1[,G2]  : Same as above, but exclude standard ones
+  --check-unused-locals   : Raise error when compiling code with unused locals
   --require-as-include    : Inline required modules in the output
   --metadata              : Enable function metadata, even in compiled output
   --no-metadata           : Disable function metadata, even in REPL
   --correlate             : Make Lua output line numbers match Fennel input
-
-  --eval SOURCE (-e)      : Evaluate source code and print the result
+  --load FILE (-l)        : Load the specified FILE before executing the command
+  --no-fennelrc           : Skip loading ~/.fennelrc when launching repl
 
   --help (-h)             : Display this text
   --version (-v)          : Show version
@@ -32,8 +34,8 @@ Run fennel, a lisp programming language for the Lua runtime.
   Metadata is typically considered a development feature and is not recommended
   for production. It is used for docstrings and enabled by default in the REPL.
 
-  When not given a flag, runs the file given as the first argument.
-  When given neither flag nor file, launches a repl.
+  When not given a command, runs the file given as the first argument.
+  When given neither command nor file, launches a repl.
 
   If ~/.fennelrc exists, loads it before launching a repl.]]
 
@@ -73,9 +75,19 @@ for i=#arg, 1, -1 do
         local entry = table.remove(arg, i+1)
         fennel.path = entry .. ";" .. fennel.path
         table.remove(arg, i)
+    elseif arg[i] == "--load" or arg[i] == "-l" then
+        local file = table.remove(arg, i+1)
+        dosafe(file, options, {})
+        table.remove(arg, i)
+    elseif arg[i] == "--no-fennelrc" then
+        options.fennelrc = false
+        table.remove(arg, i)
     elseif arg[i] == "--correlate" then
         options.correlate = true
         table.remove(arg, i)
+    elseif arg[i] == "--check-unused-locals" then
+        options.checkUnusedLocals = true
+        table.remove(arg, i)
     elseif arg[i] == "--globals" then
         allowGlobals(table.remove(arg, i+1))
         for globalName in pairs(_G) do
@@ -146,16 +158,26 @@ if arg[1] == "--repl" or #arg == 0 then
             options.pp = pp
         end
     end
-    local initFilename = (os.getenv("HOME") or "") .. "/.fennelrc"
-    local init = io.open(initFilename, "rb")
 
     tryReadline(options)
 
-    if init then
-        init:close()
-        -- pass in options so fennerlrc can make changes to it
-        dosafe(initFilename, options, options)
+    if options.fennelrc ~= false then
+        local home = os.getenv("HOME")
+        local xdg_config_home = os.getenv("XDG_CONFIG_HOME") or home .. "/.config"
+        local xdg_initfile = xdg_config_home .. "/fennel/fennelrc"
+        local home_initfile = home .. "/.fennelrc"
+        local init, initFilename = io.open(xdg_initfile, "rb"), xdg_initfile
+        if not init then
+            init, initFilename = io.open(home_initfile, "rb"), home_initfile
+        end
+
+        if init then
+            init:close()
+            -- pass in options so fennerlrc can make changes to it
+            dosafe(initFilename, options, {options})
+        end
     end
+
     print("Welcome to Fennel " .. fennel.version .. "!")
     if options.useMetadata ~= false then
         print("Use (doc something) to view documentation.")
diff --git a/lib/fennel.lua b/lib/fennel.lua
index ec5cef1..6663866 100644
--- a/lib/fennel.lua
+++ b/lib/fennel.lua
@@ -30,20 +30,42 @@ local unpack = unpack or table.unpack
 -- Main Types and support functions
 --
 
+-- Map function f over sequential table t, removing values where f returns nil.
+-- Optionally takes a target table to insert the mapped values into.
+local function map(t, f, out)
+    out = out or {}
+    if type(f) ~= "function" then local s = f f = function(x) return x[s] end end
+    for _,x in ipairs(t) do
+        local v = f(x)
+        if v then table.insert(out, v) end
+    end
+    return out
+end
+
+-- Map function f over key/value table t, similar to above, but it can return a
+-- sequential table if f returns a single value or a k/v table if f returns two.
+-- Optionally takes a target table to insert the mapped values into.
+local function kvmap(t, f, out)
+    out = out or {}
+    if type(f) ~= "function" then local s = f f = function(x) return x[s] end end
+    for k,x in pairs(t) do
+        local korv, v = f(k, x)
+        if korv and not v then table.insert(out, korv) end
+        if korv and v then out[korv] = v end
+    end
+    return out
+end
+
 local function deref(self) return self[1] end
 
-local SYMBOL_MT = { 'SYMBOL', __tostring = deref }
+local function listToString(self, tostring2)
+    return '(' .. table.concat(map(self, tostring2 or tostring), ' ', 1, #self) .. ')'
+end
+
+local SYMBOL_MT = { 'SYMBOL', __tostring = deref, __fennelview = deref }
 local EXPR_MT = { 'EXPR', __tostring = deref }
 local VARARG = setmetatable({ '...' }, { 'VARARG', __tostring = deref })
-local LIST_MT = { 'LIST',
-    __tostring = function (self)
-        local strs = {}
-        for _, s in ipairs(self) do
-            table.insert(strs, tostring(s))
-        end
-        return '(' .. table.concat(strs, ' ', 1, #self) .. ')'
-    end
-}
+local LIST_MT = { 'LIST', __tostring = listToString, __fennelview = listToString }
 local SEQUENCE_MT = { 'SEQUENCE' }
 
 -- Load code with an environment in all recent Lua versions
@@ -58,23 +80,28 @@ local function loadCode(code, environment, filename)
     end
 end
 
--- Create a new list
+-- Create a new list. Lists are a compile-time construct in Fennel; they are
+-- represented as tables with a special marker metatable. They only come from
+-- the parser, and they represent code which comes from reading a paren form;
+-- they are specifically not cons cells.
 local function list(...)
     return setmetatable({...}, LIST_MT)
 end
 
--- Create a new symbol
+-- Create a new symbol. Symbols are a compile-time construct in Fennel and are
+-- not exposed outside the compiler. Symbols have metadata describing what file,
+-- line, etc that they came from.
 local function sym(str, scope, meta)
     local s = {str, scope = scope}
-    if meta then
-        for k, v in pairs(meta) do
-            if type(k) == 'string' then s[k] = v end
-        end
+    for k, v in pairs(meta or {}) do
+        if type(k) == 'string' then s[k] = v end
     end
     return setmetatable(s, SYMBOL_MT)
 end
 
--- Create a new sequence
+-- Create a new sequence. Sequences are tables that come from the parser when
+-- it encounters a form with square brackets. They are treated as regular tables
+-- except when certain macros need to look for binding forms, etc specifically.
 local function sequence(...)
    return setmetatable({...}, SEQUENCE_MT)
 end
@@ -120,6 +147,13 @@ local function isSequence(x)
    return type(x) == 'table' and getmetatable(x) == SEQUENCE_MT and x
 end
 
+-- Returns a shallow copy of its table argument. Returns an empty table on nil.
+local function copy(from)
+   local to = {}
+   for k, v in pairs(from or {}) do to[k] = v end
+   return to
+end
+
 --
 -- Parser
 --
@@ -196,6 +230,11 @@ local prefixes = { -- prefix chars substituted while reading
     [35] = 'hashfn' -- #
 }
 
+-- The resetRoot function needs to be called at every exit point of the compiler
+-- including when there's a parse error or compiler error. Introduce it up here
+-- so error functions have access to it, and set it when we have values below.
+local resetRoot = nil
+
 -- Parse one value given a function that
 -- returns sequential bytes. Will throw an error as soon
 -- as possible without getting more bytes on bad input. Returns
@@ -228,6 +267,7 @@ local function parser(getbyte, filename)
         return r
     end
     local function parseError(msg)
+        if resetRoot then resetRoot() end
         return error(msg .. ' in ' .. (filename or 'unknown') .. ':' .. line, 0)
     end
 
@@ -254,10 +294,7 @@ local function parser(getbyte, filename)
         -- Throw nice error when we expect more characters
         -- but reach end of stream.
         local function badend()
-            local accum = {}
-            for _, item in ipairs(stack) do
-                accum[#accum + 1] = item.closer
-            end
+            local accum = map(stack, "closer")
             parseError(('expected closing delimiter%s %s'):format(
                 #stack == 1 and "" or "s",
                 string.char(unpack(accum))))
@@ -317,7 +354,8 @@ local function parser(getbyte, filename)
                     end
                     val = {}
                     for i = 1, #last, 2 do
-                        if tostring(last[i]) == ":" and isSym(last[i + 1]) then
+                        if(tostring(last[i]) == ":" and isSym(last[i + 1])
+                           and isSym(last[i])) then
                             last[i] = tostring(last[i + 1])
                         end
                         val[last[i]] = last[i + 1]
@@ -376,7 +414,7 @@ local function parser(getbyte, filename)
                 if rawstr == 'true' then dispatch(true)
                 elseif rawstr == 'false' then dispatch(false)
                 elseif rawstr == '...' then dispatch(VARARG)
-                elseif rawstr:match('^:.+$') then -- keyword style strings
+                elseif rawstr:match('^:.+$') then -- colon style strings
                     dispatch(rawstr:sub(2))
                 elseif rawstr:match("^~") and rawstr ~= "~=" then
                     -- for backwards-compatibility, special-case allowance of ~=
@@ -424,15 +462,25 @@ end
 --
 
 -- Top level compilation bindings.
-local rootChunk
-local rootScope
-local rootOptions
+local rootChunk, rootScope, rootOptions
 
--- Create a new Scope, optionally under a parent scope. Scopes are compile time constructs
--- that are responsible for keeping track of local variables, name mangling, and macros.
--- They are accessible to user code via the '*compiler' special form (may change). They
--- use metatables to implement nesting via inheritance.
+local function setResetRoot(oldChunk, oldScope, oldOptions)
+    local oldResetRoot = resetRoot -- this needs to nest!
+    resetRoot = function()
+        rootChunk, rootScope, rootOptions = oldChunk, oldScope, oldOptions
+        resetRoot = oldResetRoot
+    end
+end
+
+local GLOBAL_SCOPE
+
+-- Create a new Scope, optionally under a parent scope. Scopes are compile time
+-- constructs that are responsible for keeping track of local variables, name
+-- mangling, and macros.  They are accessible to user code via the
+-- 'eval-compiler' special form (may change). They use metatables to implement
+-- nesting via metatables.
 local function makeScope(parent)
+    if not parent then parent = GLOBAL_SCOPE end
     return {
         unmanglings = setmetatable({}, {
             __index = parent and parent.unmanglings
@@ -449,6 +497,9 @@ local function makeScope(parent)
         includes = setmetatable({}, {
             __index = parent and parent.includes
         }),
+        refedglobals = setmetatable({}, {
+            __index = parent and parent.refedglobals
+        }),
         autogensyms = {},
         parent = parent,
         vararg = parent and parent.vararg,
@@ -462,6 +513,7 @@ end
 local function assertCompile(condition, msg, ast)
     -- if we use regular `assert' we can't provide the `level' argument of zero
     if not condition then
+        if resetRoot then resetRoot() end
         error(string.format("Compile error in '%s' %s:%s: %s",
                             isSym(ast[1]) and ast[1][1] or ast[1] or '()',
                             ast.filename or "unknown", ast.line or '?', msg), 0)
@@ -469,7 +521,7 @@ local function assertCompile(condition, msg, ast)
     return condition
 end
 
-local GLOBAL_SCOPE = makeScope()
+GLOBAL_SCOPE = makeScope()
 GLOBAL_SCOPE.vararg = true
 local SPECIALS = GLOBAL_SCOPE.specials
 local COMPILER_SCOPE = makeScope(GLOBAL_SCOPE)
@@ -479,9 +531,8 @@ local luaKeywords = {
     'if', 'in', 'local', 'nil', 'not', 'or', 'repeat', 'return', 'then', 'true',
     'until', 'while'
 }
-for i, v in ipairs(luaKeywords) do
-    luaKeywords[v] = i
-end
+
+for i, v in ipairs(luaKeywords) do luaKeywords[v] = i end
 
 local function isValidLuaIdentifier(str)
     return (str:match('^[%a_][%w_]*$') and not luaKeywords[str])
@@ -553,21 +604,31 @@ end
 local function globalUnmangling(identifier)
     local rest = identifier:match('^__fnl_global__(.*)$')
     if rest then
-        return rest:gsub('_[%da-f][%da-f]', function (code)
+        local r = rest:gsub('_[%da-f][%da-f]', function (code)
             return string.char(tonumber(code:sub(2), 16))
         end)
+        return r -- don't return multiple values
     else
         return identifier
     end
 end
 
+-- If there's a provided list of allowed globals, don't let references thru that
+-- aren't on the list. This list is set at the compiler entry points of compile
+-- and compileStream.
+local allowedGlobals
+
+local function globalAllowed(name)
+    if not allowedGlobals then return true end
+    for _, g in ipairs(allowedGlobals) do
+        if g == name then return true end
+    end
+end
+
 -- Creates a symbol from a string by mangling it.
 -- ensures that the generated symbol is unique
 -- if the input string is unique in the scope.
-local function localMangling(str, scope, ast)
-    if scope.manglings[str] then
-        return scope.manglings[str]
-    end
+local function localMangling(str, scope, ast, tempManglings)
     local append = 0
     local mangling = str
     assertCompile(not isMultiSym(str), 'did not expect multi symbol ' .. str, ast)
@@ -581,16 +642,30 @@ local function localMangling(str, scope, ast)
         return ('_%02x'):format(c:byte())
     end)
 
+    -- Prevent name collisions with existing symbols
     local raw = mangling
     while scope.unmanglings[mangling] do
         mangling = raw .. append
         append = append + 1
     end
+
     scope.unmanglings[mangling] = str
-    scope.manglings[str] = mangling
+    local manglings = tempManglings or scope.manglings
+    manglings[str] = mangling
     return mangling
 end
 
+-- Calling this function will mean that further
+-- compilation in scope will use these new manglings
+-- instead of the current manglings.
+local function applyManglings(scope, newManglings, ast)
+    for raw, mangled in pairs(newManglings) do
+        assertCompile(not scope.refedglobals[mangled],
+        "use of global " .. raw .. " is aliased by a local", ast)
+        scope.manglings[raw] = mangled
+    end
+end
+
 -- Combine parts of a symbol
 local function combineParts(parts, scope)
     local ret = scope.manglings[parts[1]] or globalMangling(parts[1])
@@ -637,32 +712,20 @@ local function checkBindingValid(symbol, scope, ast)
     assertCompile(not scope.specials[name],
     ("symbol %s may be overshadowed by a special form or macro"):format(name), ast)
     assertCompile(not isQuoted(symbol), 'macro tried to bind ' .. name ..
-                      ' without gensym; try ' .. name .. '# instead', ast)
+                      " without gensym; try ' .. name .. '# instead", ast)
 
 end
 
 -- Declare a local symbol
-local function declareLocal(symbol, meta, scope, ast)
+local function declareLocal(symbol, meta, scope, ast, tempManglings)
     checkBindingValid(symbol, scope, ast)
     local name = symbol[1]
     assertCompile(not isMultiSym(name), "did not expect mutltisym", ast)
-    local mangling = localMangling(name, scope, ast)
+    local mangling = localMangling(name, scope, ast, tempManglings)
     scope.symmeta[name] = meta
     return mangling
 end
 
--- If there's a provided list of allowed globals, don't let references
--- thru that aren't on the list. This list is set at the compiler
--- entry points of compile and compileStream.
-local allowedGlobals
-
-local function globalAllowed(name)
-    if not allowedGlobals then return true end
-    for _, g in ipairs(allowedGlobals) do
-        if g == name then return true end
-    end
-end
-
 -- Convert symbol to Lua code. Will only work for local symbols
 -- if they have already been declared via declareLocal
 local function symbolToExpression(symbol, scope, isReference)
@@ -685,6 +748,9 @@ local function symbolToExpression(symbol, scope, isReference)
     -- then we need to check for allowed globals
     assertCompile(not isReference or isLocal or globalAllowed(parts[1]),
                   'unknown global in strict mode: ' .. parts[1], symbol)
+    if not isLocal then
+        rootScope.refedglobals[parts[1]] = true
+    end
     return expr(combineParts(parts, scope), etype)
 end
 
@@ -709,10 +775,7 @@ local function peephole(chunk)
         return peephole(chunk[2])
     end
     -- Recurse
-    for i, v in ipairs(chunk) do
-        chunk[i] = peephole(v)
-    end
-    return chunk
+    return map(chunk, peephole)
 end
 
 -- correlate line numbers in input with line numbers in output
@@ -753,15 +816,13 @@ local function flattenChunk(sm, chunk, tab, depth)
         if sm then sm[#sm + 1] = info and info.line or -1 end
         return code
     else
-        local parts = {}
-        for i = 1, #chunk do
-            -- Ignore empty chunks
-            if chunk[i].leaf or #(chunk[i]) > 0 then
-                local sub = flattenChunk(sm, chunk[i], tab, depth + 1)
+        local parts = map(chunk, function(c)
+            if c.leaf or #c > 0 then -- Ignore empty chunks
+                local sub = flattenChunk(sm, c, tab, depth + 1)
                 if depth > 0 then sub = tab .. sub:gsub('\n', '\n' .. tab) end
-                table.insert(parts, sub)
+                return sub
             end
-        end
+        end)
         return table.concat(parts, '\n')
     end
 end
@@ -851,16 +912,12 @@ end
 
 local function docSpecial(name, arglist, docstring)
     metadata[SPECIALS[name]] =
-        { ['fnl/docstring'] = docstring, ['fnl/arglist'] = arglist }
+        { ["fnl/docstring"] = docstring, ["fnl/arglist"] = arglist }
 end
 
 -- Convert expressions to Lua string
 local function exprs1(exprs)
-    local t = {}
-    for _, e in ipairs(exprs) do
-        t[#t + 1] = e[1]
-    end
-    return table.concat(t, ', ')
+    return table.concat(map(exprs, 1), ', ')
 end
 
 -- Compile side effects for a chunk
@@ -937,6 +994,17 @@ end
 --   'tail' - boolean indicating tail position if set. If set, form will generate a return
 --   instruction.
 --   'nval' - The number of values to compile to if it is known to be a fixed value.
+
+-- In Lua, an expression can evaluate to 0 or more values via multiple
+-- returns. In many cases, Lua will drop extra values and convert a 0 value
+-- expression to nil. In other cases, Lua will use all of the values in an
+-- expression, such as in the last argument of a function call. Nval is an
+-- option passed to compile1 to say that the resulting expression should have
+-- at least n values. It lets us generate better code, because if we know we
+-- are only going to use 1 or 2 values from an expression, we can create 1 or 2
+-- locals to store intermediate results rather than turn the expression into a
+-- closure that is called immediately, which we have to do if we don't know.
+
 local function compile1(ast, scope, parent, opts)
     opts = opts or {}
     local exprs = {}
@@ -1038,24 +1106,23 @@ local function compile1(ast, scope, parent, opts)
             local nval = i ~= #ast and 1
             buffer[#buffer + 1] = exprs1(compile1(ast[i], scope, parent, {nval = nval}))
         end
-        local keys = {}
-        for k, _ in pairs(ast) do -- Write other keys.
+        local function writeOtherValues(k)
             if type(k) ~= 'number' or math.floor(k) ~= k or k < 1 or k > #ast then
-                local kstr
                 if type(k) == 'string' and isValidLuaIdentifier(k) then
-                    kstr = k
+                    return {k, k}
                 else
-                    kstr = '[' .. tostring(compile1(k, scope, parent, {nval = 1})[1]) .. ']'
+                    local kstr = '[' .. tostring(compile1(k, scope, parent,
+                                                          {nval = 1})[1]) .. ']'
+                    return { kstr, k }
                 end
-                table.insert(keys, { kstr, k })
             end
         end
+        local keys = kvmap(ast, writeOtherValues)
         table.sort(keys, function (a, b) return a[1] < b[1] end)
-        for _, k in ipairs(keys) do
-            local v = ast[k[2]]
-            buffer[#buffer + 1] = ('%s = %s'):format(
-                k[1], tostring(compile1(v, scope, parent, {nval = 1})[1]))
-        end
+        map(keys, function(k)
+                local v = tostring(compile1(ast[k[2]], scope, parent, {nval = 1})[1])
+                return ('%s = %s'):format(k[1], v) end,
+            buffer)
         local tbl = '{' .. table.concat(buffer, ', ') ..'}'
         exprs = handleCompileOpts({expr(tbl, 'expression')}, parent, opts, ast)
     else
@@ -1096,13 +1163,15 @@ local function destructure(to, from, ast, scope, parent, opts)
     local forceset = opts.forceset
     local setter = declaration and "local %s = %s" or "%s = %s"
 
+    local newManglings = {}
+
     -- Get Lua source for symbol, and check for errors
     local function getname(symbol, up1)
         local raw = symbol[1]
         assertCompile(not (nomulti and isMultiSym(raw)),
             'did not expect multisym', up1)
         if declaration then
-            return declareLocal(symbol, {var = isvar}, scope, symbol)
+            return declareLocal(symbol, {var = isvar}, scope, symbol, newManglings)
         else
             local parts = isMultiSym(raw) or {raw}
             local meta = scope.symmeta[parts[1]]
@@ -1114,6 +1183,16 @@ local function destructure(to, from, ast, scope, parent, opts)
                 assertCompile(not (meta and not meta.var),
                     'expected local var', up1)
             end
+            if forceglobal then
+                assertCompile(not scope.symmeta[scope.unmanglings[raw]],
+                              "global " .. raw .. " conflicts with local", ast)
+                scope.manglings[raw] = globalMangling(raw)
+                scope.unmanglings[globalMangling(raw)] = raw
+                if allowedGlobals then
+                    table.insert(allowedGlobals, raw)
+                end
+            end
+
             return symbolToExpression(symbol, scope)[1]
         end
     end
@@ -1121,10 +1200,8 @@ local function destructure(to, from, ast, scope, parent, opts)
     -- Compile the outer most form. We can generate better Lua in this case.
     local function compileTopTarget(lvalues)
         -- Calculate initial rvalue
-        local inits = {}
-        for _, x in ipairs(lvalues) do
-            table.insert(inits, scope.manglings[x] and x or 'nil')
-        end
+        local inits = map(lvalues, function(x)
+                              return scope.manglings[x] and x or 'nil' end)
         local init = table.concat(inits, ', ')
         local lvalue = table.concat(lvalues, ', ')
 
@@ -1198,7 +1275,9 @@ local function destructure(to, from, ast, scope, parent, opts)
         if top then return {returned = true} end
     end
 
-    return destructure1(to, nil, ast, true)
+    local ret = destructure1(to, nil, ast, true)
+    applyManglings(scope, newManglings, ast)
+    return ret
 end
 
 -- Unlike most expressions and specials, 'values' resolves with multiple
@@ -1234,6 +1313,15 @@ local function compileDo(ast, scope, parent, start)
     end
 end
 
+-- Raises compile error if unused locals are found and we're checking for them.
+local function checkUnused(scope, ast)
+    if not rootOptions.checkUnusedLocals then return end
+    for symName in pairs(scope.symmeta) do
+        assertCompile(scope.symmeta[symName].used or symName:find("^_"),
+                      ("unused local %s"):format(symName), ast)
+    end
+end
+
 -- Implements a do statement, starting at the 'start' element. By default, start is 2.
 local function doImpl(ast, scope, parent, opts, start, chunk, subScope)
     start = start or 2
@@ -1293,20 +1381,21 @@ local function doImpl(ast, scope, parent, opts, start, chunk, subScope)
     end
     emit(parent, chunk, ast)
     emit(parent, 'end', ast)
+    checkUnused(subScope, ast)
     return retexprs
 end
 
-SPECIALS['do'] = doImpl
-docSpecial('do', {'...'}, 'Evaluate multiple forms; return last value.')
+SPECIALS["do"] = doImpl
+docSpecial("do", {"..."}, "Evaluate multiple forms; return last value.")
 
-SPECIALS['values'] = values
-docSpecial('values', {'...'},
-           'Return multiple values from a function.  Must be in tail position.')
+SPECIALS["values"] = values
+docSpecial("values", {"..."},
+           "Return multiple values from a function.  Must be in tail position.")
 
 -- The fn special declares a function. Syntax is similar to other lisps;
 -- (fn optional-name [arg ...] (body))
 -- Further decoration such as docstrings, meta info, and multibody functions a possibility.
-SPECIALS['fn'] = function(ast, scope, parent)
+SPECIALS["fn"] = function(ast, scope, parent)
     local fScope = makeScope(scope)
     local fChunk = {}
     local index = 2
@@ -1327,25 +1416,26 @@ SPECIALS['fn'] = function(ast, scope, parent)
         fnName = gensym(scope)
     end
     local argList = assertCompile(isTable(ast[index]),
-                                  'expected vector arg list [a b ...]', ast)
-    local argNameList = {}
-    for i = 1, #argList do
-        if isVarg(argList[i]) then
-            assertCompile(i == #argList, "expected vararg in last parameter position", ast)
-            argNameList[i] = '...'
+                                  "expected vector arg list [a b ...]", ast)
+    local function getArgName(i, name)
+        if isVarg(name) then
+            assertCompile(i == #argList, "expected vararg as last parameter", ast)
             fScope.vararg = true
-        elseif(isSym(argList[i]) and argList[i][1] ~= "nil"
-               and not isMultiSym(argList[i][1])) then
-            argNameList[i] = declareLocal(argList[i], {}, fScope, ast)
-        elseif isTable(argList[i]) then
+            return "..."
+        elseif(isSym(name) and deref(name) ~= "nil"
+               and not isMultiSym(deref(name))) then
+            return declareLocal(name, {}, fScope, ast)
+        elseif isTable(name) then
             local raw = sym(gensym(scope))
-            argNameList[i] = declareLocal(raw, {}, fScope, ast)
-            destructure(argList[i], raw, ast, fScope, fChunk,
+            local declared = declareLocal(raw, {}, fScope, ast)
+            destructure(name, raw, ast, fScope, fChunk,
                         { declaration = true, nomulti = true })
+            return declared
         else
-            assertCompile(false, 'expected symbol for function parameter', ast)
+            assertCompile(false, "expected symbol for function parameter", ast)
         end
     end
+    local argNameList = kvmap(argList, getArgName)
     if type(ast[index + 1]) == 'string' and index + 1 < #ast then
         index = index + 1
         docstring = ast[index]
@@ -1368,11 +1458,10 @@ SPECIALS['fn'] = function(ast, scope, parent)
     emit(parent, 'end', ast)
 
     if rootOptions.useMetadata then
-        local args = {}
-        for i, v in ipairs(argList) do
+        local args = map(argList, function(v)
             -- TODO: show destructured args properly instead of replacing
-            args[i] =  isTable(v) and '"#<table>"' or string.format('"%s"', tostring(v))
-        end
+            return isTable(v) and '"#<table>"' or string.format('"%s"', tostring(v))
+        end)
 
         local metaFields = {
             '"fnl/arglist"', '{' .. table.concat(args, ', ') .. '}',
@@ -1388,13 +1477,14 @@ SPECIALS['fn'] = function(ast, scope, parent)
                                    fnName, table.concat(metaFields, ', ')))
     end
 
+    checkUnused(fScope, ast)
     return expr(fnName, 'sym')
 end
-docSpecial('fn', {'name?', 'args', 'docstring?', '...'},
-           'Function syntax. May optionally include a name and docstring.'
-               ..'\nIf a name is provided, the function will be bound in the current scope.'
-               ..'\nWhen called with the wrong number of args, excess args will be discarded'
-               ..'\nand lacking args will be nil; use lambda for arity-checked functions.')
+docSpecial("fn", {"name?", "args", "docstring?", "..."},
+           "Function syntax. May optionally include a name and docstring."
+               .."\nIf a name is provided, the function will be bound in the current scope."
+               .."\nWhen called with the wrong number of args, excess args will be discarded"
+               .."\nand lacking args will be nil, use lambda for arity-checked functions.")
 
 -- (lua "print('hello!')") -> prints hello, evaluates to nil
 -- (lua "print 'hello!'" "10") -> prints hello, evaluates to the number 10
@@ -1427,11 +1517,11 @@ SPECIALS['doc'] = function(ast, scope, parent)
             :format(rootOptions.moduleName or "fennel", value, tostring(ast[2]))
     end
 end
-docSpecial('doc', {'x'},
-           'Print the docstring and arglist for a function, macro, or special form.')
+docSpecial("doc", {"x"},
+           "Print the docstring and arglist for a function, macro, or special form.")
 
 -- Table lookup
-SPECIALS['.'] = function(ast, scope, parent)
+SPECIALS["."] = function(ast, scope, parent)
     local len = #ast
     assertCompile(len > 1, "expected table argument", ast)
     local lhs = compile1(ast[2], scope, parent, {nval = 1})
@@ -1456,51 +1546,45 @@ SPECIALS['.'] = function(ast, scope, parent)
         end
     end
 end
-docSpecial('.', {'tbl', 'key1', '...'},
-           'Look up key1 in tbl table. If more args are provided, do a nested lookup.')
+docSpecial(".", {"tbl", "key1", "..."},
+           "Look up key1 in tbl table. If more args are provided, do a nested lookup.")
 
-SPECIALS['global'] = function(ast, scope, parent)
+SPECIALS["global"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
-    -- globals tracking doesn't currently work with multi-values/destructuring
-    if allowedGlobals and isSym(ast[2]) then
-        for _,global in ipairs(isList(ast[2]) and ast[2] or {ast[2]}) do
-            table.insert(allowedGlobals, deref(global))
-        end
-    end
     destructure(ast[2], ast[3], ast, scope, parent, {
         nomulti = true,
         forceglobal = true
     })
 end
-docSpecial('global', {'name', 'val'}, 'Set name as a global with val.')
+docSpecial("global", {"name", "val"}, "Set name as a global with val.")
 
-SPECIALS['set'] = function(ast, scope, parent)
+SPECIALS["set"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         noundef = true
     })
 end
-docSpecial('set', {'name', 'val'},
-           'Set a local variable to a new value. Only works on locals using var.')
+docSpecial("set", {"name", "val"},
+           "Set a local variable to a new value. Only works on locals using var.")
 
-SPECIALS['set-forcibly!'] = function(ast, scope, parent)
+SPECIALS["set-forcibly!"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         forceset = true
     })
 end
 
-SPECIALS['local'] = function(ast, scope, parent)
+SPECIALS["local"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         declaration = true,
         nomulti = true
     })
 end
-docSpecial('local', {'name', 'val'},
-           'Introduce new top-level immutable local.')
+docSpecial("local", {"name", "val"},
+           "Introduce new top-level immutable local.")
 
-SPECIALS['var'] = function(ast, scope, parent)
+SPECIALS["var"] = function(ast, scope, parent)
     assertCompile(#ast == 3, "expected name and value", ast)
     destructure(ast[2], ast[3], ast, scope, parent, {
         declaration = true,
@@ -1508,16 +1592,16 @@ SPECIALS['var'] = function(ast, scope, parent)
         isvar = true
     })
 end
-docSpecial('var', {'name', 'val'},
-           'Introduce new mutable local.')
+docSpecial("var", {"name", "val"},
+           "Introduce new mutable local.")
 
-SPECIALS['let'] = function(ast, scope, parent, opts)
+SPECIALS["let"] = function(ast, scope, parent, opts)
     local bindings = ast[2]
     assertCompile(isList(bindings) or isTable(bindings),
-                  'expected table for destructuring', ast)
+                  "expected table for destructuring", ast)
     assertCompile(#bindings % 2 == 0,
-                  'expected even number of name/value bindings', ast)
-    assertCompile(#ast >= 3, 'missing body expression', ast)
+                  "expected even number of name/value bindings", ast)
+    assertCompile(#ast >= 3, "missing body expression", ast)
     local subScope = makeScope(scope)
     local subChunk = {}
     for i = 1, #bindings, 2 do
@@ -1528,12 +1612,12 @@ SPECIALS['let'] = function(ast, scope, parent, opts)
     end
     return doImpl(ast, scope, parent, opts, 3, subChunk, subScope)
 end
-docSpecial('let', {'[name1 val1 ... nameN valN]', '...'},
-           'Introduces a new scope in which a given set of local bindings are used.')
+docSpecial("let", {"[name1 val1 ... nameN valN]", "..."},
+           "Introduces a new scope in which a given set of local bindings are used.")
 
 -- For setting items in a table
-SPECIALS['tset'] = function(ast, scope, parent)
-    assertCompile(#ast > 3, ('tset form needs table, key, and value'), ast)
+SPECIALS["tset"] = function(ast, scope, parent)
+    assertCompile(#ast > 3, ("tset form needs table, key, and value"), ast)
     local root = compile1(ast[2], scope, parent, {nval = 1})[1]
     local keys = {}
     for i = 3, #ast - 1 do
@@ -1543,17 +1627,18 @@ SPECIALS['tset'] = function(ast, scope, parent)
     local value = compile1(ast[#ast], scope, parent, {nval = 1})[1]
     local rootstr = tostring(root)
     -- Prefix 'do end ' so parens are not ambiguous (grouping or function call?)
-    local fmtstr = (rootstr:match('^{')) and 'do end (%s)[%s] = %s' or '%s[%s] = %s'
+    local fmtstr = (rootstr:match("^{")) and "do end (%s)[%s] = %s" or "%s[%s] = %s"
     emit(parent, fmtstr:format(tostring(root),
                                table.concat(keys, ']['),
                                tostring(value)), ast)
 end
-docSpecial('tset', {'tbl', 'key1', 'val1', '...', 'keyN', 'valN'},
-           'Set the fields of a table to new values. Takes 1 or more key/value pairs.')
+docSpecial("tset", {"tbl", "key1", "...", "keyN", "val"},
+           "Set the value of a table field. Can take additional keys to set"
+        .. "nested values,\nbut all parents must contain an existing table.")
 
 -- The if special form behaves like the cond form in
 -- many languages
-SPECIALS['if'] = function(ast, scope, parent, opts)
+SPECIALS["if"] = function(ast, scope, parent, opts)
     local doScope = makeScope(scope)
     local branches = {}
     local elseBranch = nil
@@ -1635,6 +1720,10 @@ SPECIALS['if'] = function(ast, scope, parent, opts)
             if hasElse then
                 emit(lastBuffer, 'else', ast)
                 emit(lastBuffer, elseBranch.chunk, ast)
+            -- TODO: Consolidate use of condLine ~= "else" with hasElse
+            elseif(innerTarget and condLine ~= 'else') then
+                emit(lastBuffer, 'else', ast)
+                emit(lastBuffer, ("%s = nil"):format(innerTarget), ast)
             end
             emit(lastBuffer, 'end', ast)
         elseif not branches[i + 1].nested then
@@ -1666,60 +1755,63 @@ SPECIALS['if'] = function(ast, scope, parent, opts)
         return targetExprs
     end
 end
-docSpecial('if', {'cond1', 'body1', '...', 'condN', 'bodyN'},
-           'Conditional form.\n' ..
-               'Takes any number of condition/body pairs and evaluates the first body where'
-               .. '\nthe condition evaluates to truthy. Similar to cond in other lisps.')
+docSpecial("if", {"cond1", "body1", "...", "condN", "bodyN"},
+           "Conditional form.\n" ..
+               "Takes any number of condition/body pairs and evaluates the first body where"
+               .. "\nthe condition evaluates to truthy. Similar to cond in other lisps.")
 
 -- (each [k v (pairs t)] body...) => []
-SPECIALS['each'] = function(ast, scope, parent)
-    local binding = assertCompile(isTable(ast[2]), 'expected binding table', ast)
+SPECIALS["each"] = function(ast, scope, parent)
+    local binding = assertCompile(isTable(ast[2]), "expected binding table", ast)
     local iter = table.remove(binding, #binding) -- last item is iterator call
-    local bindVars = {}
     local destructures = {}
-    for _, v in ipairs(binding) do
-        assertCompile(isSym(v) or isTable(v),
-                      'expected iterator symbol or table', ast)
-        if(isSym(v)) then
-            table.insert(bindVars, declareLocal(v, {}, scope, ast))
+    local newManglings = {}
+    local function destructureBinding(v)
+        assertCompile(isSym(v) or isTable(v), "expected iterator symbol or table", ast)
+        if isSym(v) then
+            return declareLocal(v, {}, scope, ast, newManglings)
         else
             local raw = sym(gensym(scope))
             destructures[raw] = v
-            table.insert(bindVars, declareLocal(raw, {}, scope, ast))
+            return declareLocal(raw, {}, scope, ast)
         end
     end
-    emit(parent, ('for %s in %s do'):format(
-             table.concat(bindVars, ', '),
-             tostring(compile1(iter, scope, parent, {nval = 1})[1])), ast)
+    local bindVars = map(binding, destructureBinding)
+    local vals = compile1(iter, scope, parent)
+    local valNames = map(vals, tostring)
+
+    emit(parent, ('for %s in %s do'):format(table.concat(bindVars, ', '),
+                                            table.concat(valNames, ", ")), ast)
     local chunk = {}
     for raw, args in pairs(destructures) do
         destructure(args, raw, ast, scope, chunk,
                     { declaration = true, nomulti = true })
     end
+    applyManglings(scope, newManglings, ast)
     compileDo(ast, scope, chunk, 3)
     emit(parent, chunk, ast)
     emit(parent, 'end', ast)
 end
-docSpecial('each', {'[key value (iterator)]', '...'},
-           'Runs the body once for each set of values provided by the given iterator.'
-           ..'\nMost commonly used with ipairs for sequential tables or pairs for'
-               ..' undefined\norder, but can be used with any iterator.')
+docSpecial("each", {"[key value (iterator)]", "..."},
+           "Runs the body once for each set of values provided by the given iterator."
+           .."\nMost commonly used with ipairs for sequential tables or pairs for"
+               .." undefined\norder, but can be used with any iterator.")
 
 -- (while condition body...) => []
-SPECIALS['while'] = function(ast, scope, parent)
+SPECIALS["while"] = function(ast, scope, parent)
     local len1 = #parent
     local condition = compile1(ast[2], scope, parent, {nval = 1})[1]
     local len2 = #parent
     local subChunk = {}
     if len1 ~= len2 then
         -- Compound condition
-        emit(parent, 'while true do', ast)
         -- Move new compilation to subchunk
         for i = len1 + 1, len2 do
             subChunk[#subChunk + 1] = parent[i]
             parent[i] = nil
         end
-        emit(parent, ('if %s then break end'):format(condition[1]), ast)
+        emit(parent, 'while true do', ast)
+        emit(subChunk, ('if not %s then break end'):format(condition[1]), ast)
     else
         -- Simple condition
         emit(parent, 'while ' .. tostring(condition) .. ' do', ast)
@@ -1728,13 +1820,13 @@ SPECIALS['while'] = function(ast, scope, parent)
     emit(parent, subChunk, ast)
     emit(parent, 'end', ast)
 end
-docSpecial('while', {'condition', '...'},
-           'The classic while loop. Evaluates body until a condition is non-truthy.')
+docSpecial("while", {"condition", "..."},
+           "The classic while loop. Evaluates body until a condition is non-truthy.")
 
-SPECIALS['for'] = function(ast, scope, parent)
-    local ranges = assertCompile(isTable(ast[2]), 'expected binding table', ast)
+SPECIALS["for"] = function(ast, scope, parent)
+    local ranges = assertCompile(isTable(ast[2]), "expected binding table", ast)
     local bindingSym = assertCompile(isSym(table.remove(ast[2], 1)),
-                                     'expected iterator symbol', ast)
+                                     "expected iterator symbol", ast)
     local rangeArgs = {}
     for i = 1, math.min(#ranges, 3) do
         rangeArgs[i] = tostring(compile1(ranges[i], scope, parent, {nval = 1})[1])
@@ -1747,11 +1839,11 @@ SPECIALS['for'] = function(ast, scope, parent)
     emit(parent, chunk, ast)
     emit(parent, 'end', ast)
 end
-docSpecial('for', {'[index start stop step?]', '...'}, 'Numeric loop construct.' ..
-               '\nEvaluates body once for each value between start and stop (inclusive).')
+docSpecial("for", {"[index start stop step?]", "..."}, "Numeric loop construct." ..
+               "\nEvaluates body once for each value between start and stop (inclusive).")
 
-SPECIALS[':'] = function(ast, scope, parent)
-    assertCompile(#ast >= 3, 'expected at least 3 arguments', ast)
+SPECIALS[":"] = function(ast, scope, parent)
+    assertCompile(#ast >= 3, "expected at least 3 arguments", ast)
     -- Compile object
     local objectexpr = compile1(ast[2], scope, parent, {nval = 1})[1]
     -- Compile method selector
@@ -1770,9 +1862,7 @@ SPECIALS[':'] = function(ast, scope, parent)
         local subexprs = compile1(ast[i], scope, parent, {
             nval = i ~= #ast and 1 or nil
         })
-        for j = 1, #subexprs do
-            args[#args + 1] = tostring(subexprs[j])
-        end
+        map(subexprs, tostring, args)
     end
     local fstring
     if not methodident then
@@ -1791,21 +1881,21 @@ SPECIALS[':'] = function(ast, scope, parent)
         methodstring,
         table.concat(args, ', ')), 'statement')
 end
-docSpecial(':', {'tbl', 'method-name', '...'},
-           'Call the named method on tbl with the provided args.'..
-           '\nMethod name doesn\'t have to be known at compile-time; if it is, use'
-               ..'\n(tbl:method-name ...) instead.')
+docSpecial(":", {"tbl", "method-name", "..."},
+           "Call the named method on tbl with the provided args."..
+           "\nMethod name doesn\"t have to be known at compile-time; if it is, use"
+               .."\n(tbl:method-name ...) instead.")
 
-SPECIALS['comment'] = function(ast, _, parent)
+SPECIALS["comment"] = function(ast, _, parent)
     local els = {}
     for i = 2, #ast do
         els[#els + 1] = tostring(ast[i]):gsub('\n', ' ')
     end
     emit(parent, '              -- ' .. table.concat(els, ' '), ast)
 end
-docSpecial('comment', {'...'}, 'Comment which will be emitted in Lua output.')
+docSpecial("comment", {"..."}, "Comment which will be emitted in Lua output.")
 
-SPECIALS['hashfn'] = function(ast, scope, parent)
+SPECIALS["hashfn"] = function(ast, scope, parent)
     assertCompile(#ast == 2, "expected one argument", ast)
     local fScope = makeScope(scope)
     local fChunk = {}
@@ -1826,7 +1916,7 @@ SPECIALS['hashfn'] = function(ast, scope, parent)
     emit(parent, 'end', ast)
     return expr(name, 'sym')
 end
-docSpecial('hashfn', {'...'}, 'Function literal shorthand; args are $1, $2, etc.')
+docSpecial("hashfn", {"..."}, "Function literal shorthand; args are $1, $2, etc.")
 
 local function defineArithmeticSpecial(name, zeroArity, unaryPrefix)
     local paddedOp = ' ' .. name .. ' '
@@ -1841,9 +1931,7 @@ local function defineArithmeticSpecial(name, zeroArity, unaryPrefix)
                 local subexprs = compile1(ast[i], scope, parent, {
                     nval = (i == 1 and 1 or nil)
                 })
-                for j = 1, #subexprs do
-                    operands[#operands + 1] = tostring(subexprs[j])
-                end
+                map(subexprs, tostring, operands)
             end
             if #operands == 1 then
                 if unaryPrefix then
@@ -1856,8 +1944,8 @@ local function defineArithmeticSpecial(name, zeroArity, unaryPrefix)
             end
         end
     end
-    docSpecial(name, {'a', 'b', '...'},
-               'Arithmetic operator; works the same as Lua but accepts more arguments.')
+    docSpecial(name, {"a", "b", "..."},
+               "Arithmetic operator; works the same as Lua but accepts more arguments.")
 end
 
 defineArithmeticSpecial('+', '0')
@@ -1871,18 +1959,18 @@ defineArithmeticSpecial('//', nil, '1')
 defineArithmeticSpecial('or', 'false')
 defineArithmeticSpecial('and', 'true')
 
-docSpecial('and', {'a', 'b', '...'},
-           'Boolean operator; works the same as Lua but accepts more arguments.')
-docSpecial('or', {'a', 'b', '...'},
-           'Boolean operator; works the same as Lua but accepts more arguments.')
-docSpecial('..', {'a', 'b', '...'},
-           'String concatenation operator; works the same as Lua but accepts more arguments.')
+docSpecial("and", {"a", "b", "..."},
+           "Boolean operator; works the same as Lua but accepts more arguments.")
+docSpecial("or", {"a", "b", "..."},
+           "Boolean operator; works the same as Lua but accepts more arguments.")
+docSpecial("..", {"a", "b", "..."},
+           "String concatenation operator; works the same as Lua but accepts more arguments.")
 
 local function defineComparatorSpecial(name, realop, chainOp)
     local op = realop or name
     SPECIALS[name] = function(ast, scope, parent)
         local len = #ast
-        assertCompile(len > 2, 'expected at least two arguments', ast)
+        assertCompile(len > 2, "expected at least two arguments", ast)
         local lhs = compile1(ast[2], scope, parent, {nval = 1})[1]
         local lastval = compile1(ast[3], scope, parent, {nval = 1})[1]
         -- avoid double-eval by introducing locals for possible side-effects
@@ -1901,8 +1989,8 @@ local function defineComparatorSpecial(name, realop, chainOp)
         end
         return out
     end
-    docSpecial(name, {name, 'a', 'b', '...'},
-               'Comparison operator; works the same as Lua but accepts more arguments.')
+    docSpecial(name, {"a", "b", "..."},
+               "Comparison operator; works the same as Lua but accepts more arguments.")
 end
 
 defineComparatorSpecial('>')
@@ -1921,12 +2009,12 @@ local function defineUnarySpecial(op, realop)
     end
 end
 
-defineUnarySpecial('not', 'not ')
-docSpecial('not', {'x'}, 'Boolean operator; works the same as Lua.')
+defineUnarySpecial("not", "not ")
+docSpecial("not", {"x"}, "Logical operator; works the same as Lua.")
 
-defineUnarySpecial('length', '#')
-docSpecial('length', {'x'}, 'Returns the length of a table or string.')
-SPECIALS['#'] = SPECIALS['length']
+defineUnarySpecial("length", "#")
+docSpecial("length", {"x"}, "Returns the length of a table or string.")
+SPECIALS["#"] = SPECIALS["length"]
 
 -- Save current macro scope
 local macroCurrentScope = GLOBAL_SCOPE
@@ -1951,38 +2039,20 @@ end
 
 local requireSpecial
 local function compile(ast, options)
-    options = options or {}
+    local opts = copy(options)
     local oldGlobals = allowedGlobals
-    local oldChunk = rootChunk
-    local oldScope = rootScope
-    local oldOptions = rootOptions
-    allowedGlobals = options.allowedGlobals
-    if options.indent == nil then options.indent = '  ' end
+    setResetRoot(rootChunk, rootScope, rootOptions)
+    allowedGlobals = opts.allowedGlobals
+    if opts.indent == nil then opts.indent = '  ' end
     local chunk = {}
-    local scope = options.scope or makeScope(GLOBAL_SCOPE)
-    rootChunk = chunk
-    rootScope = scope
-    rootOptions = options
-    if options.requireAsInclude then scope.specials.require = requireSpecial end
+    local scope = opts.scope or makeScope(GLOBAL_SCOPE)
+    rootChunk, rootScope, rootOptions = chunk, scope, opts
+    if opts.requireAsInclude then scope.specials.require = requireSpecial end
     local exprs = compile1(ast, scope, chunk, {tail = true})
     keepSideEffects(exprs, chunk, nil, ast)
     allowedGlobals = oldGlobals
-    rootChunk = oldChunk
-    rootScope = oldScope
-    rootOptions = oldOptions
-    return flatten(chunk, options)
-end
-
--- map a function across all pairs in a table
-local function quoteTmap(f, t)
-    local res = {}
-    for k,v in pairs(t) do
-        local nk, nv = f(k, v)
-        if nk then
-            res[nk] = nv
-        end
-    end
-    return res
+    resetRoot()
+    return flatten(chunk, opts)
 end
 
 -- make a transformer for key / value table pairs, preserving all numeric keys
@@ -2040,11 +2110,11 @@ local function doQuote (form, scope, parent, runtime)
     -- list
     elseif isList(form) then
         assertCompile(not runtime, "lists may only be used at compile time", form)
-        local mapped = quoteTmap(entryTransform(no, q), form)
+        local mapped = kvmap(form, entryTransform(no, q))
         return 'list(' .. mixedConcat(mapped, ", ") .. ')'
     -- table
     elseif type(form) == 'table' then
-        local mapped = quoteTmap(entryTransform(q, q), form)
+        local mapped = kvmap(form, entryTransform(q, q))
         return '{' .. mixedConcat(mapped, ", ") .. '}'
     -- string
     elseif type(form) == 'string' then
@@ -2066,24 +2136,20 @@ end
 docSpecial('quote', {'x'}, 'Quasiquote the following form. Only works in macro/compiler scope.')
 
 local function compileStream(strm, options)
-    options = options or {}
+    local opts = copy(options)
     local oldGlobals = allowedGlobals
-    local oldChunk = rootChunk
-    local oldScope = rootScope
-    local oldOptions = rootOptions
-    allowedGlobals = options.allowedGlobals
-    if options.indent == nil then options.indent = '  ' end
-    local scope = options.scope or makeScope(GLOBAL_SCOPE)
-    if options.requireAsInclude then scope.specials.require = requireSpecial end
+    setResetRoot(rootChunk, rootScope, rootOptions)
+    allowedGlobals = opts.allowedGlobals
+    if opts.indent == nil then opts.indent = '  ' end
+    local scope = opts.scope or makeScope(GLOBAL_SCOPE)
+    if opts.requireAsInclude then scope.specials.require = requireSpecial end
     local vals = {}
-    for ok, val in parser(strm, options.filename) do
+    for ok, val in parser(strm, opts.filename) do
         if not ok then break end
         vals[#vals + 1] = val
     end
     local chunk = {}
-    rootChunk = chunk
-    rootScope = scope
-    rootOptions = options
+    rootChunk, rootScope, rootOptions = chunk, scope, opts
     for i = 1, #vals do
         local exprs = compile1(vals[i], scope, chunk, {
             tail = i == #vals,
@@ -2091,10 +2157,8 @@ local function compileStream(strm, options)
         keepSideEffects(exprs, chunk, nil, vals[i])
     end
     allowedGlobals = oldGlobals
-    rootChunk = oldChunk
-    rootScope = oldScope
-    rootOptions = oldOptions
-    return flatten(chunk, options)
+    resetRoot()
+    return flatten(chunk, opts)
 end
 
 local function compileString(str, options)
@@ -2127,14 +2191,10 @@ local function wrapEnv(env)
         -- checking the __pairs metamethod won't work automatically in Lua 5.1
         -- sadly, but it's important for 5.2+ and can be done manually in 5.1
         __pairs = function()
-            local pt = {}
-            for key, value in pairs(env) do
-                if type(key) == 'string' then
-                    pt[globalUnmangling(key)] = value
-                else
-                    pt[key] = value
-                end
+            local function putenv(k, v)
+                return type(k) == 'string' and globalUnmangling(k) or k, v
             end
+            local pt = kvmap(env, putenv)
             return next, pt, nil
         end,
     })
@@ -2147,8 +2207,12 @@ local function traceback(msg, start)
     local level = start or 2 -- Can be used to skip some frames
     local lines = {}
     if msg then
-        local stripped = msg:gsub('^[^:]*:%d+:%s+', 'runtime error: ')
-        table.insert(lines, stripped)
+        if msg:find("^Compile error") then
+            table.insert(lines, msg)
+        else
+            local newmsg = msg:gsub('^[^:]*:%d+:%s+', 'runtime error: ')
+            table.insert(lines, newmsg)
+        end
     end
     table.insert(lines, 'stack traceback:')
     while true do
@@ -2187,212 +2251,44 @@ local function traceback(msg, start)
 end
 
 local function currentGlobalNames(env)
-    local names = {}
-    for k in pairs(env or _G) do
-       k = globalUnmangling(k)
-       table.insert(names, k)
-    end
-    return names
+    return kvmap(env or _G, globalUnmangling)
 end
 
 local function eval(str, options, ...)
-    options = options or {}
+    local opts = copy(options)
     -- eval and dofile are considered "live" entry points, so we can assume
     -- that the globals available at compile time are a reasonable allowed list
     -- UNLESS there's a metatable on env, in which case we can't assume that
     -- pairs will return all the effective globals; for instance openresty
     -- sets up _G in such a way that all the globals are available thru
     -- the __index meta method, but as far as pairs is concerned it's empty.
-    if options.allowedGlobals == nil and not getmetatable(options.env) then
-        options.allowedGlobals = currentGlobalNames(options.env)
+    if opts.allowedGlobals == nil and not getmetatable(opts.env) then
+        opts.allowedGlobals = currentGlobalNames(opts.env)
     end
-    local env = options.env and wrapEnv(options.env)
-    local luaSource = compileString(str, options)
+    local env = opts.env and wrapEnv(opts.env)
+    local luaSource = compileString(str, opts)
     local loader = loadCode(luaSource, env,
-        options.filename and ('@' .. options.filename) or str)
+                            opts.filename and ('@' .. opts.filename) or str)
+    opts.filename = nil
     return loader(...)
 end
 
 local function dofileFennel(filename, options, ...)
-    options = options or {}
-    if options.allowedGlobals == nil then
-        options.allowedGlobals = currentGlobalNames(options.env)
+    local opts = copy(options)
+    if opts.allowedGlobals == nil then
+        opts.allowedGlobals = currentGlobalNames(opts.env)
     end
     local f = assert(io.open(filename, "rb"))
     local source = f:read("*all"):gsub("^#![^\n]*\n", "")
     f:close()
-    options.filename = options.filename or filename
-    return eval(source, options, ...)
-end
-
--- Implements a configurable repl
-local function repl(options)
-
-    local opts = options or {}
-    -- This would get set for us when calling eval, but we want to seed it
-    -- with a value that is persistent so it doesn't get reset on each eval.
-    if opts.allowedGlobals == nil then
-        opts.allowedGlobals = currentGlobalNames(opts.env)
-    end
-
-    opts.useMetadata = options.useMetadata ~= false
-    opts.moduleName = options.moduleName
-    rootOptions = opts
-
-    local env = opts.env and wrapEnv(opts.env) or setmetatable({}, {
-        __index = _ENV or _G
-    })
-
-    local function defaultReadChunk(parserState)
-        io.write(parserState.stackSize > 0 and '.. ' or '>> ')
-        io.flush()
-        local input = io.read()
-        return input and input .. '\n'
-    end
-
-    local function defaultOnValues(xs)
-        io.write(table.concat(xs, '\t'))
-        io.write('\n')
-    end
-
-    local function defaultOnError(errtype, err, luaSource)
-        if (errtype == 'Lua Compile') then
-            io.write('Bad code generated - likely a bug with the compiler:\n')
-            io.write('--- Generated Lua Start ---\n')
-            io.write(luaSource .. '\n')
-            io.write('--- Generated Lua End ---\n')
-        end
-        if (errtype == 'Runtime') then
-            io.write(traceback(err, 4))
-            io.write('\n')
-        else
-            io.write(('%s error: %s\n'):format(errtype, tostring(err)))
-        end
-    end
-
-    local envdbg = (opts.env or _G)["debug"]
-    -- if the environment doesn't support debug.getlocal you can't save locals
-    local saveLocals = opts.saveLocals ~= false and envdbg and envdbg.getlocal
-    local saveSource = table.
-       concat({"local ___i___ = 1",
-               "while true do",
-               " local name, value = debug.getlocal(1, ___i___)",
-               " if(name and name ~= \"___i___\") then",
-               " ___replLocals___[name] = value",
-               " ___i___ = ___i___ + 1",
-               " else break end end"}, "\n")
-
-    -- we do some source munging in order to save off locals from each chunk
-    -- and reintroduce them to the beginning of the next chunk, allowing
-    -- locals to work in the repl the way you'd expect them to.
-       local spliceSaveLocals = function(luaSource)
-        env.___replLocals___ = env.___replLocals___ or {}
-        local splicedSource = {}
-        for line in luaSource:gmatch("([^\n]+)\n?") do
-            table.insert(splicedSource, line)
-        end
-        -- reintroduce locals from the previous time around
-        local bind = "local %s = ___replLocals___['%s']"
-        for name in pairs(env.___replLocals___) do
-            table.insert(splicedSource, 1, bind:format(name, name))
-        end
-        -- save off new locals at the end - if safe to do so (i.e. last line is a return)
-        if (string.match(splicedSource[#splicedSource], "^ *return .*$")) then
-            if (#splicedSource > 1) then
-                table.insert(splicedSource, #splicedSource, saveSource)
-            end
-        end
-        return table.concat(splicedSource, "\n")
-    end
-
-    -- Read options
-    local readChunk = opts.readChunk or defaultReadChunk
-    local onValues = opts.onValues or defaultOnValues
-    local onError = opts.onError or defaultOnError
-    local pp = opts.pp or tostring
-
-    -- Make parser
-    local bytestream, clearstream = granulate(readChunk)
-    local chars = {}
-    local read, reset = parser(function (parserState)
-        local c = bytestream(parserState)
-        chars[#chars + 1] = c
-        return c
-    end)
-
-    local scope = makeScope(GLOBAL_SCOPE)
-
-    local replCompleter = function(text)
-        local matches = {}
-        local inputFragment = text:gsub("[%s)(]*(.+)", "%1")
-
-        -- adds any matching keys from the provided generator/iterator to matches
-        local function addMatchesFromGen(next, param, state)
-          for k in next, param, state do
-            if #matches >= 40 then break -- cap completions at 40 to avoid overwhelming
-            elseif inputFragment == k:sub(0, #inputFragment) then
-                table.insert(matches, k)
-            end
-          end
-        end
-        addMatchesFromGen(pairs(env._ENV or env._G or {}))
-        addMatchesFromGen(pairs(env.___replLocals___ or {}))
-        addMatchesFromGen(pairs(SPECIALS or {}))
-        addMatchesFromGen(pairs(scope.specials or {}))
-        return matches
-    end
-    if opts.registerCompleter then opts.registerCompleter(replCompleter) end
-
-    -- REPL loop
-    while true do
-        chars = {}
-        local ok, parseok, x = pcall(read)
-        local srcstring = string.char(unpack(chars))
-        if not ok then
-            onError('Parse', parseok)
-            clearstream()
-            reset()
-        else
-            if not parseok then break end -- eof
-            local compileOk, luaSource = pcall(compile, x, {
-                correlate = opts.correlate,
-                source = srcstring,
-                scope = scope,
-                useMetadata = opts.useMetadata,
-                moduleName = opts.moduleName,
-            })
-            if not compileOk then
-                clearstream()
-                onError('Compile', luaSource) -- luaSource is error message in this case
-            else
-                if saveLocals then
-                    luaSource = spliceSaveLocals(luaSource)
-                end
-                local luacompileok, loader = pcall(loadCode, luaSource, env)
-                if not luacompileok then
-                    clearstream()
-                    onError('Lua Compile', loader, luaSource)
-                else
-                    local loadok, ret = xpcall(function () return {loader()} end,
-                        function (runtimeErr)
-                            onError('Runtime', runtimeErr)
-                        end)
-                    if loadok then
-                        env._ = ret[1]
-                        env.__ = ret
-                        for i = 1, #ret do ret[i] = pp(ret[i]) end
-                        onValues(ret)
-                    end
-                end
-            end
-        end
-    end
+    opts.filename = filename
+    return eval(source, opts, ...)
 end
 
 local macroLoaded = {}
 
 local pathTable = {"./?.fnl", "./?/init.fnl"}
-local osPath = os.getenv("FENNEL_PATH")
+local osPath = os and os.getenv and os.getenv("FENNEL_PATH")
 if osPath then
     table.insert(pathTable, osPath)
 end
@@ -2405,6 +2301,7 @@ local module = {
     compileString = compileString,
     compileStream = compileStream,
     compile1 = compile1,
+    loadCode = loadCode,
     mangle = globalMangling,
     unmangle = globalUnmangling,
     list = list,
@@ -2413,14 +2310,166 @@ local module = {
     scope = makeScope,
     gensym = gensym,
     eval = eval,
-    repl = repl,
     dofile = dofileFennel,
     macroLoaded = macroLoaded,
     path = table.concat(pathTable, ";"),
     traceback = traceback,
-    version = "0.3.0",
+    version = "0.4.0-dev",
 }
 
+-- In order to make this more readable, you can switch your editor to treating
+-- this file as if it were Fennel for the purposes of this section
+local replsource = [===[(local (fennel internals) ...)
+
+(fn default-read-chunk [parser-state]
+  (io.write (if (< 0 parser-state.stackSize) ".." ">> "))
+  (io.flush)
+  (let [input (io.read)]
+    (and input (.. input "\n"))))
+
+(fn default-on-values [xs]
+  (io.write (table.concat xs "\t"))
+  (io.write "\n"))
+
+(fn default-on-error [errtype err lua-source]
+  (io.write
+   (match errtype
+     "Lua Compile" (.. "Bad code generated - likely a bug with the compiler:\n"
+                       "--- Generated Lua Start ---\n"
+                       lua-source
+                       "--- Generated Lua End ---\n")
+     "Runtime" (.. (fennel.traceback err 4) "\n")
+     _ (: "%s error: %s\n" :format errtype (tostring err)))))
+
+(local save-source
+       (table.concat ["local ___i___ = 1"
+                      "while true do"
+                      " local name, value = debug.getlocal(1, ___i___)"
+                      " if(name and name ~= \"___i___\") then"
+                      " ___replLocals___[name] = value"
+                      " ___i___ = ___i___ + 1"
+                      " else break end end"] "\n"))
+
+(fn splice-save-locals [env lua-source]
+  (set env.___replLocals___ (or env.___replLocals___ {}))
+  (let [spliced-source []
+        bind "local %s = ___replLocals___['%s']"]
+    (each [line (lua-source:gmatch "([^\n]+)\n?")]
+      (table.insert spliced-source line))
+    (each [name (pairs env.___replLocals___)]
+      (table.insert spliced-source 1 (bind:format name name)))
+    (when (and (: (. spliced-source (# spliced-source)) :match "^ *return .*$")
+               (< 1 (# spliced-source)))
+      (table.insert spliced-source (# spliced-source) save-source))
+    (table.concat spliced-source "\n")))
+
+(fn completer [env scope text]
+  (let [matches []
+        input-fragment (text:gsub ".*[%s)(]+" "")]
+    (fn add-partials [input tbl prefix] ; add partial key matches in tbl
+      (each [k (pairs tbl)]
+        (let [k (if (or (= tbl env) (= tbl env.___replLocals___))
+                    (. scope.unmanglings k)
+                    k)]
+          (when (and (< (# matches) 40)
+                     (= (type k) "string")
+                     (= input (k:sub 0 (# input))))
+            (table.insert matches (.. prefix k))))))
+    (fn add-matches [input tbl prefix] ; add matches, descending into tbl fields
+      (let [prefix (if prefix (.. prefix ".") "")]
+        (if (not (input:find "%.")) ; no more dots, so add matches
+            (add-partials input tbl prefix)
+            (let [(head tail) (input:match "^([^.]+)%.(.*)")
+                  raw-head (if (or (= tbl env) (= tbl env.___replLocals___))
+                               (. scope.manglings head)
+                               head)]
+              (when (= (type (. tbl raw-head)) "table")
+                (add-matches tail (. tbl raw-head) (.. prefix head)))))))
+
+    (add-matches input-fragment (or scope.specials []))
+    (add-matches input-fragment (or internals.SPECIALS []))
+    (add-matches input-fragment (or env.___replLocals___ []))
+    (add-matches input-fragment env)
+    (add-matches input-fragment (or env._ENV env._G []))
+    matches))
+
+(fn repl [options]
+  (let [old-root-options internals.rootOptions
+        env (if options.env
+                (internals.wrapEnv options.env)
+                (setmetatable {} {:__index (or _G._ENV _G)}))
+        save-locals? (and (not= options.saveLocals false)
+                          env.debug env.debug.getlocal)
+        opts {}
+        _ (each [k v (pairs options)] (tset opts k v))
+        read-chunk (or opts.readChunk default-read-chunk)
+        on-values (or opts.onValues default-on-values)
+        on-error (or opts.onError default-on-error)
+        pp (or opts.pp tostring)
+        ;; make parser
+        (byte-stream clear-stream) (fennel.granulate read-chunk)
+        chars []
+        (read reset) (fennel.parser (fn [parser-state]
+                                      (let [c (byte-stream parser-state)]
+                                        (tset chars (+ (# chars) 1) c)
+                                        c)))
+        scope (fennel.scope)]
+
+    ;; use metadata unless we've specifically disabled it
+    (set opts.useMetadata (not= options.useMetadata false))
+    (when (= opts.allowedGlobals nil)
+      (set opts.allowedGlobals (internals.currentGlobalNames opts.env)))
+
+    (when opts.registerCompleter
+      (opts.registerCompleter (partial completer env scope)))
+
+    (fn loop []
+      (each [k (pairs chars)] (tset chars k nil))
+      (let [(ok parse-ok? x) (pcall read)
+            src-string (string.char ((or _G.unpack table.unpack) chars))]
+        (internals.setRootOptions opts)
+        (if (not ok)
+            (do (on-error "Parse" parse-ok?)
+                (clear-stream)
+                (reset)
+                (loop))
+            (when parse-ok? ; if this is false, we got eof
+              (match (pcall fennel.compile x {:correlate opts.correlate
+                                              :source src-string
+                                              :scope scope
+                                              :useMetadata opts.useMetadata
+                                              :moduleName opts.moduleName})
+                (false msg) (do (clear-stream)
+                                (on-error "Compile" msg))
+                (true source) (let [source (if save-locals?
+                                               (splice-save-locals env source)
+                                               source)
+                                    (lua-ok? loader) (pcall fennel.loadCode
+                                                            source env)]
+                                (if (not lua-ok?)
+                                    (do (clear-stream)
+                                        (on-error "Lua Compile" loader source))
+                                    (match (xpcall #[(loader)]
+                                                   (partial on-error "Runtime"))
+                                      (true ret)
+                                      (do (set env._ (. ret 1))
+                                          (set env.__ ret)
+                                          (on-values (internals.map ret pp)))))))
+              (internals.setRootOptions old-root-options)
+              (loop)))))
+    (loop)))]===]
+
+module.repl = function(options)
+    -- functionality the repl needs that isn't part of the public API yet
+    local internals = { rootOptions = rootOptions,
+                        setRootOptions = function(r) rootOptions = r end,
+                        currentGlobalNames = currentGlobalNames,
+                        wrapEnv = wrapEnv,
+                        SPECIALS = SPECIALS,
+                        map = map }
+    return eval(replsource, { correlate = true }, module, internals)(options)
+end
+
 local function searchModule(modulename, pathstring)
     modulename = modulename:gsub("%.", "/")
     for path in string.gmatch((pathstring or module.path)..";", "([^;]*);") do
@@ -2438,8 +2487,7 @@ module.makeSearcher = function(options)
       -- this will propagate options from the repl but not from eval, because
       -- eval unsets rootOptions after compiling but before running the actual
       -- calls to require.
-      local opts = {}
-      for k,v in pairs(rootOptions or {}) do opts[k] = v end
+      local opts = copy(rootOptions)
       for k,v in pairs(options or {}) do opts[k] = v end
       local filename = searchModule(modulename)
       if filename then
@@ -2490,24 +2538,14 @@ local function makeCompilerEnv(ast, scope, parent)
 end
 
 local function macroGlobals(env, globals)
-    local allowed = {}
-    for k in pairs(env) do
-        local g = globalUnmangling(k)
-        table.insert(allowed, g)
-    end
-    if globals then
-        for _, k in pairs(globals) do
-            table.insert(allowed, k)
-        end
-    end
+    local allowed = currentGlobalNames(env)
+    for _, k in pairs(globals or {}) do table.insert(allowed, k) end
     return allowed
 end
 
 local function addMacros(macros, ast, scope)
     assertCompile(isTable(macros), 'expected macros to be table', ast)
-    for k, v in pairs(macros) do
-        scope.specials[k] = macroToSpecial(v)
-    end
+    kvmap(macros, function(k, v) return k, macroToSpecial(v) end, scope.specials)
 end
 
 local function loadMacros(modname, ast, scope, parent)
@@ -2548,10 +2586,7 @@ SPECIALS['include'] = function(ast, scope, parent, opts)
     local mod = loadCode(code)()
 
     -- Check cache
-    local includeExpr = scope.includes[mod]
-    if includeExpr then
-        return includeExpr
-    end
+    if scope.includes[mod] then return scope.includes[mod] end
 
     -- Find path to source
     local path = searchModule(mod)
@@ -2573,32 +2608,45 @@ SPECIALS['include'] = function(ast, scope, parent, opts)
     local s = f:read('*all')
     f:close()
 
-    -- splice in source and memoize it
-    -- so we can include it again without duplication
-    local target = gensym(scope)
-    local ret = expr(target, 'sym')
+    -- splice in source and memoize it in compiler AND package.preload
+    -- so we can include it again without duplication, even in runtime
+    local target = 'package.preload["' .. mod .. '"]'
+    local ret = expr('require("' .. mod .. '")', 'statement')
+
+    local subChunk, tempChunk = {}, {}
+    emit(tempChunk, subChunk, ast)
+    -- if lua, simply emit the setting of package.preload
+    if not isFennel then
+        emit(tempChunk, target .. ' = ' .. target .. ' or function()\n' .. s .. 'end', ast)
+    end
+    -- Splice tempChunk to begining of rootChunk
+    for i, v in ipairs(tempChunk) do
+        table.insert(rootChunk, i, v)
+    end
+
+    -- For fnl source, compile subChunk AFTER splicing into start of rootChunk.
     if isFennel then
-        local p = parser(stringStream(s), path)
-        local forms = list(sym('do'))
-        for _, val in p do table.insert(forms, val) end
+        local subopts = { nval = 1, target = target }
         local subscope = makeScope(rootScope.parent)
         if rootOptions.requireAsInclude then
             subscope.specials.require = requireSpecial
         end
-        local subopts = {
-            nval = 1,
-            target = target
-        }
-        emit(rootChunk, 'local ' .. target, ast)
-        compile1(forms, subscope, rootChunk, subopts)
-    else
-        emit(rootChunk, 'local ' .. target .. ' = (function() ' .. s .. ' end)()', ast)
+        local targetForm = list(sym('.'), sym('package.preload'), mod)
+        -- splice "or" statement in so it uses existing package.preload[modname]
+        -- if it's been set by something else, allowing for overrides
+        local forms = list(sym('or'), targetForm, list(sym('fn'), sequence()))
+        local p = parser(stringStream(s), path)
+        for _, val in p do table.insert(forms[3], val) end
+        compile1(forms, subscope, subChunk, subopts)
     end
 
     -- Put in cache and return
     rootScope.includes[mod] = ret
     return ret
 end
+docSpecial('include', {'module-name-literal'},
+           'Like require, but load the target module during compilation and embed it in the\n'
+        .. 'Lua output. The module must be a string literal and resolvable at compile time.')
 
 local function requireFallback(e)
     local code = ('require(%s)'):format(tostring(e))
@@ -2795,7 +2843,7 @@ that argument name begins with ?."
                   (do (assert (not (. pattern (+ k 2)))
                               "expected rest argument in final position")
                       (table.insert bindings (. pattern (+ k 1)))
-                      (table.insert bindings [`(select ,k ((or unpack table.unpack)
+                      (table.insert bindings [`(select ,k ((or _G.unpack table.unpack)
                                                            ,val))]))
                   (and (= :number (type k))
                        (= "&" (tostring (. pattern (- k 1)))))
@@ -2846,19 +2894,21 @@ do
     local moduleName = "__fennel-bootstrap__"
     package.preload[moduleName] = function() return module end
     local env = makeCompilerEnv(nil, COMPILER_SCOPE, {})
-    for name, fn in pairs(eval(stdmacros, {
-        env = env,
-        scope = makeScope(COMPILER_SCOPE),
-        -- assume the code to load globals doesn't have any mistaken globals,
-        -- otherwise this can be problematic when loading fennel in contexts
-        -- where _G is an empty table with an __index metamethod. (openresty)
-        allowedGlobals = false,
-        useMetadata = true,
-        filename = "built-ins",
-        moduleName = moduleName,
-    })) do
-        SPECIALS[name] = macroToSpecial(fn, name)
-    end
+    local macros = eval(stdmacros, {
+                            env = env,
+                            scope = makeScope(COMPILER_SCOPE),
+                            -- assume the code to load globals doesn't have any
+                            -- mistaken globals, otherwise this can be
+                            -- problematic when loading fennel in contexts
+                            -- where _G is an empty table with an __index
+                            -- metamethod. (openresty)
+                            allowedGlobals = false,
+                            useMetadata = true,
+                            filename = "built-ins",
+                            moduleName = moduleName })
+    kvmap(macros,
+          function(name, fn) return name, macroToSpecial(fn, name) end,
+          SPECIALS)
     package.preload[moduleName] = nil
 end
 SPECIALS['λ'] = SPECIALS['lambda']
diff --git a/lib/fennelview.lua b/lib/fennelview.lua
index 0ecb721..5497cb1 100644
--- a/lib/fennelview.lua
+++ b/lib/fennelview.lua
@@ -15,9 +15,9 @@ do
   long_control_char_escapes = long
 end
 local function escape(str)
-  local str = str:gsub("\\", "\\\\")
-  local str = str:gsub("(%c)%f[0-9]", long_control_char_escapes)
-  return str:gsub("%c", short_control_char_escapes)
+  local str0 = str:gsub("\\", "\\\\")
+  local str1 = str0:gsub("(%c)%f[0-9]", long_control_char_escapes)
+  return str1:gsub("%c", short_control_char_escapes)
 end
 local function sequence_key_3f(k, len)
   return ((type(k) == "number") and (1 <= k) and (k <= len) and (math.floor(k) == k))
@@ -103,11 +103,14 @@ local function put_sequential_table(self, t, len)
   puts(self, "[")
   self.level = (self.level + 1)
   for i = 1, len do
-    puts(self, " ")
+    local _0_ = (1 + len)
+    if ((1 < i) and (i < _0_)) then
+      puts(self, " ")
+    end
     put_value(self, t[i])
   end
   self.level = (self.level - 1)
-  return puts(self, " ]")
+  return puts(self, "]")
 end
 local function put_key(self, k)
   if ((type(k) == "string") and k:find("^[-%w?\\^_!$%&*+./@:|<=>]+$")) then
@@ -136,10 +139,26 @@ local function put_kv_table(self, t, ordered_keys)
   return puts(self, "}")
 end
 local function put_table(self, t)
+  local metamethod = nil
+  do
+    local _0_0 = t
+    if _0_0 then
+      local _1_0 = getmetatable(_0_0)
+      if _1_0 then
+        metamethod = _1_0.__fennelview
+      else
+        metamethod = _1_0
+      end
+    else
+      metamethod = _0_0
+    end
+  end
   if (already_visited_3f(self, t) and self["detect-cycles?"]) then
     return puts(self, "#<table ", get_id(self, t), ">")
   elseif (self.level >= self.depth) then
     return puts(self, "{...}")
+  elseif metamethod then
+    return puts(self, metamethod(t, self.fennelview))
   elseif "else" then
     local non_seq_keys, len = get_nonsequential_keys(t)
     local id = get_id(self, t)
@@ -172,20 +191,23 @@ local function one_line(str)
   return ret
 end
 local function fennelview(x, options)
-  local options = (options or {})
-  local inspector = inspector
-  local function _1_()
-    if options["one-line"] then
+  local options0 = (options or {})
+  local inspector = nil
+  local function _1_(_241)
+    return fennelview(_241, options0)
+  end
+  local function _2_()
+    if options0["one-line"] then
       return ""
     else
       return "  "
     end
   end
-  inspector = {["detect-cycles?"] = not (false == options["detect-cycles?"]), ["max-ids"] = {}, appearances = count_table_appearances(x, {}), buffer = {}, depth = (options.depth or 128), ids = {}, indent = (options.indent or _1_()), level = 0}
+  inspector = {["detect-cycles?"] = not (false == options0["detect-cycles?"]), ["max-ids"] = {}, appearances = count_table_appearances(x, {}), buffer = {}, depth = (options0.depth or 128), fennelview = _1_, ids = {}, indent = (options0.indent or _2_()), level = 0}
   put_value(inspector, x)
   do
     local str = table.concat(inspector.buffer)
-    if options["one-line"] then
+    if options0["one-line"] then
       return one_line(str)
     else
       return str