https://github.com/nixpulvis/lalrpop-lambda

A λ-calculus grammar/interpretor written using LALRPOP and `λ!`.
https://github.com/nixpulvis/lalrpop-lambda

Last synced: 9 days ago
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A λ-calculus grammar/interpretor written using LALRPOP and `λ!`.

• Host: GitHub
• URL: https://github.com/nixpulvis/lalrpop-lambda
• Owner: nixpulvis
• License: mit
• Created: 2019-06-01T17:39:07.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2024-05-06T20:00:03.000Z (6 months ago)
• Last Synced: 2024-05-22T20:34:12.157Z (6 months ago)
• Language: Rust
• Homepage: https://crates.io/crates/lalrpop-lambda
• Size: 843 KB
• Stars: 83
• Watchers: 5
• Forks: 6
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-rust-formalized-reasoning - lalrpop-lambda - lambda):star: - λ-calculus grammar/interpretor written using LALRPOP and `λ!`. (Lambda Calculus / Libraries)

README

        
# λ-calculus Parser (using LALRPOP)

[![Build Status](https://travis-ci.org/nixpulvis/lalrpop-lambda.svg?branch=master)](https://travis-ci.org/nixpulvis/lalrpop-lambda)

[![Crates.io Version](https://img.shields.io/crates/v/lalrpop-lambda.svg?color=%238035b9)](https://crates.io/crates/lalrpop-lambda)

[![docs.rs](https://img.shields.io/badge/docs.rs-0.x.x-lightgrey.svg)](https://docs.rs/lalrpop-lambda)

Write lambda calculus with ease, and evaluate it. There are a number of ways to

use this library (each interchangeable with another):

- `Expression` AST variants `Abs`, `App`, and `Var`

- Macros `abs!`/`λ!`, `app!`/`γ!`, and `var!`

  ```rust

  let id = λ!{x.x};

  let one = λ!{f.λ!{x.γ!(f,x)}};

  assert_eq!(1u64, u64::from(app!({id},{one})));

  ```

- Parsed λ-calculus strings

  ```rust

  let parser = ExpressionParser::new();

  parser.parse(r"\a b.a");

  parser.parse(r"\f x.(f (f x))");

  parser.parse(r"\\\x y z");

  ```

- Native types: `u64`, `bool`, `fn` (WIP)

  ```rust

  assert_eq!(λ!{f.λ!{x.γ!(f,γ!(f,x))}}, Expression::from(2u64));

  assert_eq!(true, bool::from(λ!{a.λ!{b.a}}));

  assert_eq!(1, λ!{x.x}(1));

  ```

![](extra/site-demo.gif)

The above is generated with `wasm-pack`, see [example/site][example/site].

### Usage (Rust)

```toml

[dependencies]

lalrpop_lambda = "*"

```

Read the [Rust documentation](https://docs.rs/lalrpop-lambda) for more

information.

### Usage (WASM/JS)

An `Exp` structure is provided through WASM for use in JS. This allows cross

platform, client-side, web based interfaces to be built for the λ-calculus.

Read the [WASM documentation][lalrpop_lambda-wasm] for more information.

### Development

This assumes you have an updated and working copy of [`rustup`][rustup].

```sh

cargo +nightly [build | test | bench | doc | run --example <>]

```

##### WASM

First make sure you have `wasm-pack` installed. Then:

```

wasm-pack build

cd examples/site

npm run serve

```

[example/site]: https://github.com/nixpulvis/lalrpop-lambda/blob/master/examples/site/index.js

[lalrpop_lambda-wasm]: https://docs.rs/lalrpop-lambda/latest/lalrpop_lambda/wasm/index.html