https://github.com/novara754/yu

A toy programming language implemented in Haskell.
https://github.com/novara754/yu

Last synced: 24 days ago
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A toy programming language implemented in Haskell.

• Host: GitHub
• URL: https://github.com/novara754/yu
• Owner: novara754
• License: mit
• Created: 2020-09-07T17:01:13.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2020-10-03T16:43:13.000Z (about 4 years ago)
• Last Synced: 2024-01-14T23:13:17.745Z (10 months ago)
• Language: Haskell
• Size: 82 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
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# yu

An imperative toy programming language.

## Usage

**Requirements:** [GHC and Cabal](https://www.haskell.org/ghcup/#).

The project can be compiled using `cabal build`. It can also be ran using `cabal run`.

Currently the program will lex & parse the source code, report potential errors and if no errors

were found it will print the AST.

```

$ cabal run yu -- ./examples/simple.yu

```

## Examples

**Note:** Not fully functional, subject to change.

[`examples/simple.yu`](./examples/simple.yu)

```

module main;

/*

 * Add two integers, double result and return it.

 */

fun addTwice(x: int, y: int): int {

    return (x + y) * 2;

}

/*

 * Entry point of the program.

 */

fun main() {

    let x: int = 5;

    let y = 10;

    let z = addTwice(x, y);

    print(z); // -> 30

}

```

## Grammar

```

module        ::= (decl)* 

decl          ::= module_decl

                | function_decl

module_decl   ::= "module" IDENT ";"

function_decl ::= "fun" IDENT "(" param ("," param)* ")" "{" (statement ";")* "}"

param         ::= IDENT ":" IDENT

statement     ::= var_decl

                | return

var_decl      ::= "let" IDENT (":" IDENT) "=" expr

return        ::= "return" expr

expr          ::= expr_pre (call_tail)* (op_tail)*

expr_pre      ::= literal

                | IDENT

                | "(" expr ")"

call_tail     ::= "(" expr ("," expr)* ")"

literal       ::= INT_LITERAL

op_tail       ::= operator expr

OP_IDENT      ::= _one or more punctuation characters_

INT_LITERAL   ::= _one or more decimal digits_

IDENT         ::= _one or more alphanumeric characters or underscore_

```

## License

Licensed under the [MIT License](./LICENSE).