Gabelang

Overview

This is a language I am writing in rust for fun and to learn more about lexers, parsers, interpreters, and to dymistify programming languages in general.
The Writing an Interpreter in Go book by Thorsten Ball was used as a reference and insperation for this project as well as mkdb by Antonio Sarosi.

BNF / Language Grammer

``bnf
= |
= | | | |
= let = ;
= = ;
= if
= while
= for( ; )
= fn
= {}
= (<_param_idents>)
<_param_idents> = | <_param_idents>, <_param_idents>
= |
= | _
= | | | | | |
= ()
=
= + | - | * | /
= | |
= []
= .
= ()
= {}
= : | ,
= []
= | ,
= |
= 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0
`

Commenting

Comment your code using the //comment syntax
Any text to the right of a double slash does not make it to the parser or interpretter and will not be evaluated as code

`
// This function doubles a number
fn double_num(num) {
// Multiplies num by 2 to get the answer
return num * 2;
}
`

Variable Behavior

- When a variable is used as an expression/rvalue it is deep cloned

Built in Functions

len(obj) -> number

- returns the length of an array or string
- returns the amount of keys in an object
- throws an error if provided with something other than an array or string

___

reverse(obj) -> number

- returns a new reversed array or string without changing the parameter object
- throws an error if provided with something other than an array or string

___

abs(number) -> number

- returns the absolute value of a passed in number
- throws an error if provided with something other than a number

Build

Build with
`sh
cargo build --release
`

Build for wasm target

Requires wasm-pack to be installed
`sh
cargo install wasm-pack
`

Build with
`sh
wasm-pack build --features wasm
`

Install

Requires cargo to be installed

Install gabelang with
`sh
cargo install gabelang
`

Run

Run as repl with
`sh
gabelang
`
or run a script with
`sh
gabelang --file [script name]
`

Test

Run tests with
`sh
cargo test
``

Todo

- Better Documentation
- Built in Functions(print, file, fetch, input)
- Add tests to ast and eval modules
- Add fun language syntax

$3

- Add tooling/language server
- Add bytecode compiler
- Create VM that can run bytecode