fastexpr.js

A blazingly fast, single-file, zero dependency JavaScript expression parser.

Features

• Fast. Hand-coded lexer and top-down operator precedence parser. Twice as fast as esprima.
• Small. Less than 10KB minified and gzipped.
• Compatible. Parses all valid JavaScript expressions. Produces an esprima style AST.

Usage:

import{parse}from'@anpete/fastexpr';constexpr=(s)=>`hello from ${s}!`;constast=parse(expr.toString());console.log(ast);

which produces:

{type: "ArrowFunctionExpression",params: [{type: "IdentifierExpression",name: "s"}],body: {type: "TemplateLiteralExpression",quasis: [{type: "TemplateExpression",value: {cooked: "hello from "},tail: false},{type: "TemplateExpression",value: {cooked: "!"},tail: true}],expressions: [{type: "IdentifierExpression",name: "s"}]}}