λii Developer Playground

Experiment with λ-calculus powered functions in real-time. Write, run, and visualize your functional programs instantly.

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λii Interpreter: Ready for your code →

Try These Examples

import { Lambda } from 'lambda-ii';

const factorial = Lambda.create(n => 
  n === 0 ? 1 : n * factorial(n - 1));

const map = Lambda.create((f, xs) => 
  xs.length === 0 ? []
   : [f(xs[0])].concat(map(f, xs.slice(1))));

const Y = f => (x => x(x))(
  y => f(z => y(y)(z)));