LambdaJSON-js

1.1.8 verified Fri May 01 auth: no javascript

A compiler that translates LambdaJSON — a pure functional programming language represented in JSON — into executable JavaScript functions. Current stable version is 1.1.8. The library is designed for embedding functional logic defined entirely in JSON, with no external dependencies and a small footprint. Key differentiators: no runtime, compiles to plain JS; pure functional semantics; good for dynamic expression evaluation in JSON-based systems. Release cadence is irregular.

Common errors

error SyntaxError: import { compile } from 'lambdajson-js'; ↓

cause Running in a CommonJS module (require not supported).

fix

Change to 'type': 'module' in package.json or use dynamic import().

error TypeError: compile is not a function ↓

cause Importing default instead of named export compile.

fix

Use import { compile } from 'lambdajson-js' (named import).

error Error: ReferenceError: x is not defined ↓

cause Referencing undefined variable in LambdaJSON program.

fix

Ensure all variables used in the program are defined in the scope or passed as arguments.

Warnings

breaking LambdaJSON-js is ESM-only; requires Node >= 12.22 or modern browser. ↓

fix Ensure project is ESM (type: 'module' in package.json) or use dynamic import.

breaking The compile function throws if the LambdaJSON program contains undefined variables. ↓

fix Wrap compile in try/catch or validate program structure beforehand.

gotcha Functions compiled with compile are closures capturing the original program; avoid sharing compiled functions across different program versions. ↓

fix Create a new compiled function for each program.

deprecated The old 'run' function (directly executes LambdaJSON) was removed in v1.1.0. ↓

fix Use compile() to get a function, then call it.

Install

npm install lambdajson-js

yarn add lambdajson-js

pnpm add lambdajson-js

Imports

compile

wrong

const compile = require('lambdajson-js')

correct

import { compile } from 'lambdajson-js'

ESM only; no CommonJS support.

evalProgram

wrong

import evalProgram from 'lambdajson-js'

correct

import { evalProgram } from 'lambdajson-js'

evalProgram is a named export, not default.

VERSION

wrong

const VERSION = require('lambdajson-js').VERSION

correct

import { VERSION } from 'lambdajson-js'

ESM-only; use named import.

Quickstart

Demonstrates compiling a LambdaJSON program that sums the input with 2 and executing it.

import { compile } from 'lambdajson-js';

const program = {
    $sum: ['#', 2]
};
const f = compile(program);

console.log(f(1)); // => 3