%title Nix the Language
:nix:
%date 190921-1402

Trying to understand the Nix Language

Nix is a functional source grabber and builder. It's not really a package manager, only incidentally so.
(Nixpkgs notwithstanding?)

`nix repl` is your friend!

= AttrSets =
The building block datastructure in Nix. Basically just a DictionarySet 

```nix
{
	<attributes> = ...;
}
```

= Functions =
	Nix functions work kinda like Haskell, but no types
	
```nix
> double = x: x*2
> double 2
> 4
```

Since nix is fucking Haskell, arguments get passed through currying

```nix
> add = x: y: x + y
> add 2 3
> 5
```
	
It's good practice to pass arguments as AttrSets
You can also pass default arguments
But functions take exactly what they define. Nothing more, nothing less. 

```nix
> add = {x, y ? 2}: x+y
> add {x = 2;}
> 4
> add {x=2; y=3}
> 5
```

If you want other thigs you can do it this way

```nix
> add = s@{x, y, ...}: x + y + s.z
> add {x=2;y=2;z=1;a=1;}
> 5
```

= Builtins =	
	Nix comes with a lot of builtin functions, but doesn't want to pollute scope. So most the functions are scoped under `builtins.` 
	https://nixos.org/manual/nix/stable/#ssec-builtins

= Derivations =
	One of the functions that Nix includes in all scopes is the `derivation` function
	It takes a few arguments, does some Nix magic, and produces a `Derivation`. Kinda like a .o file in C or the .class file in Java. It's not quite a real package yet. Nix still needs to build it
	
	builder
	name
	output


= Nixpkgs =
	nix-store

= Building process =
	/tmp
	$PATH, $HOME
	outs

= Flakes =

= NixOS =
	Modules