# neb
### an attempt at a language

## ideas
 - **Lisp-y**: I hope you like parentheses!
 - **Strongly typed**: types are Good, and could enable future compilation
 - **We <3 Linux**: strong support for pipelines and shell-ing out
 - **Immutable variables**: mutability is scary and makes for strange bugs
 - **Pure functions**: side effects are also scary

## things that (hopefully) work

### housekeeping
 - TODO `(exit [[status :int]]) => :bool`

### io
 - `(print [out :string]) => :bool ; print to stdout`
 - TODO `(print-all [strings :list]) => :bool ; a list of strings`

### math
 - `(+ [arg :number] [many :number]) => :number`
 - `(- [arg :number] [many :number]) => :number`
 - `(* [arg :number] [many :number]) => :number`

### string
 - TODO `(concat [arg :string] [many :string]) => :string`

### flow control
 - `(if [cond :bool] [t-branch :any|:expr] [[f-branch :any|:expr]]) => :any`

### type checking TODO
 - `(string? [arg :any]) => :bool`
 - `(int? [arg :any]) => :bool`
 - `(float? [arg :any]) => :bool`
 - `(number? [arg :any]) => :bool ; returns #true for :int or :float`
 - `(bool? [arg :any]) => :bool`

### type conversion TODO
 - `(int->string [arg :int]) => :string`
 - `(float->string [arg :float]) => :string`
 - `(number->string [arg :number]) => :string`
 - `(bool->string [arg :bool]) => :string`
 - `(->string [arg :literal]) => :string ; works for all literals`

### global variables
 - `(def [name :string] [value :expr]) => ?`

### shell TODO
 - `($ [command :string]) => :list ; doesn't support pipes, first item is return code`
 - `($| [commands :list]) => :bool ; pipes together multiple shell commands`

### functions
 - `(lambda (args) (expr1) (expr2) ... (exprN)) => :any

### other
 - pretty much nothing else

## TODO (this section may be incomplete)

### types
- [ ] revisit type system when i understand *gestures broadly*

### parsing
- [x] build an AST like a real person (sorta?)

### math
- [ ] division (float)
- [ ] division (int)
- [ ] mod (int)
- [ ] exponent

### strings
- [x] concat
- [ ] substring
- [ ] lower/uppercase

### flow control
- [x] if
- [x] if with empty else
- [ ] branch
- [ ] pipe

### lists
- [x] lex
- [x] parse
- [x] evaluate

### other structure things
- [ ] generic struct?
- [ ] dict?

### symbols
- [x] define
- [x] access

### shell
- [x] call out
- [x] pipe