LC Compiler for Codewars

Written by Kacarott and JohanWiltink

Install

$ npm i --save @codewars/lambda-calculus

Usage

NOTE: When writing tests on Codewars, you can use the predefined wrapper module "./files.js" to get the solution file instead of using fs like below.

import { readFileSync } from "fs";
// Import module
import * as LC from "@codewars/lambda-calculus";

// Set config options
LC.config.purity = "Let";
LC.config.numEncoding = "Church";

const code = readFileSync("solution.lc", {encoding: "utf8"});
// Compile
const solution = compile(code).TRUE;
// or
const {TRUE,FALSE} = compile(code);

// Use
console.log(solution(true)(false)); // true
// or
console.log(TRUE(true)(false)) // true

Documentation

---

compile :: String -> {String: (Term -> Term)}

compile is the main entry point of the module. Compiles the specified text according the current config options, and returns an object binding all defined terms to their corresponding functions.

---

config :: {String: String}

config is an object which provides the interface for controlling how compilation behaves. Currently there are three configurable properties: purity, numEncoding and verbosity.

Property	Option	Description
purity	Let	Allows definition of named terms which can be used in subsequent definitions. Does not support recursion.
	LetRec	The same as Let, but additionally supporting direct recursion.
	PureLC (default)	Pure lambda calculus only. Terms are still named so that they can be accessed by tests, but named terms may not be used elsewhere.
numEncoding	None	No number encoding. Use of number literals will cause an error.
	Church Scott BinaryScott	Number literals will be automatically converted to corresponding LC terms, according to the encoding chosen.
verbosity	Calm Concise Loquacious Verbose	Controls the amount of information that will be reported during compilation.

Container Image

The container image used by the Code Runner is available on GHCR.

docker pull ghcr.io/codewars/lambda-calculus:latest

Building

The image can be built from this repository:

docker build -t ghcr.io/codewars/lambda-calculus:latest .

Usage

See example/ to learn how to use the image to test locally.