Editor

Abstract Syntax Tree

Examples of Valid LET Programs

let x = 5 in x
Result: 5
let x = 3 in let y = 2 in -(x,y)
Result: 1
let x = 3 in let y = 3 in if zero?(-(x,y)) then 1 else 0
Result: 1

LETjs

LET is a programming language originally described in Scheme by Daniel P. Friedman and Mitchell Wand in Exploration of Programming Languages.

This is an implementation of LET created in JavaScript using jison to generate the parser.

The LET language is a toy language with a very basic grammar. A program consists of a single expression which may be made up of multiple expressions itself.