https://github.com/dwayne/elm-monkey-interpreter

A Monkey interpreter written in Elm.
https://github.com/dwayne/elm-monkey-interpreter

elm interpreter monkey

Last synced: about 2 months ago
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A Monkey interpreter written in Elm.

• Host: GitHub
• URL: https://github.com/dwayne/elm-monkey-interpreter
• Owner: dwayne
• Created: 2022-06-02T12:29:16.000Z (over 2 years ago)
• Default Branch: master
• Last Pushed: 2022-06-06T11:20:01.000Z (over 2 years ago)
• Last Synced: 2024-04-16T03:17:52.194Z (8 months ago)
• Topics: elm, interpreter, monkey
• Language: Elm
• Homepage: https://elm-monkey-interpreter.netlify.app/
• Size: 117 KB
• Stars: 8
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• awesome-elm-pltd - elm-monkey-interpreter - A [Monkey](https://monkeylang.org) interpreter written in Elm. (Languages / Interpreters)

README

        
# Elm Monkey Interpreter ([Playground](https://elm-monkey-interpreter.netlify.app/))

A [Monkey](https://monkeylang.org/) interpreter written in

[Elm](https://elm-lang.org/).

Monkey is a programming language designed by

[Thorsten Ball](https://thorstenball.com/) that is fully described in his

[interpreter](https://interpreterbook.com/) book.

## Syntax

The syntax of Monkey is scattered throughout the pages of the book. However, I

extracted a [context-free grammar](grammar.ebnf) that you can use to learn the

syntax.

```

let filter = fn (pred, arr) {

  let iter = fn (arr, accumulated) {

    if (len(arr) == 0) {

      accumulated

    } else {

      if (pred(first(arr))) {

        iter(rest(arr), push(accumulated, first(arr)))

      } else {

        iter(rest(arr), accumulated)

      }

    }

  };

  iter(arr, [])

};

let mod = fn (a, b) {

  a - a / b * b

};

let isEven = fn (n) {

  mod(n, 2) == 0

};

filter(isEven, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

```

You can also use the [parser tests](tests/Test/Monkey/Parser.elm) as a guide.

## Semantics

The semantics is defined by the [interpreter](src/Monkey/Interpreter.elm). You

can get a sense for it by reading through the extensive suite of

[interpreter tests](tests/Test/Monkey/Interpreter.elm).