lua_to_cpls/src/lexer.js

A tool capable of compiling a subset of Lua to Please lang compiled files

const {makeLexer, moo} = require('moo-ignore');

const lexer = makeLexer({
  whitespace: {match: /\s+|--.*/, lineBreaks: true},
  identifier: {match: /[_a-zA-Z]\w*/, type: moo.keywords(
    [
      'and', 'break', 'do', 'else', 'elseif', 'end',
      'false', 'for', 'function', 'goto', 'if', 'in',
      'local', 'nil', 'not', 'or', 'repeat', 'return',
      'then', 'true', 'until', 'while'
    ].reduce((keywords, s) => {
        keywords['keywords_' + s] = s;
        return keywords;
    }, {}),
  )},
  string: {match: /'(?:[^'\\]|\\.)*?'|"(?:[^"\\]|\\.)*?"/, value: string => JSON.parse(string)},
  number: {match: /[-+]?\d*\.?\d+(?:[eE][-+]?\d+)?/, value: num => Number(num)},
  plus: '+',
  minus: '-',
  star: '*',
  slash: '/',
  modulo: '%',
  power: '^',
  comparison: '==',
  equal: '=',
  greaterEqual: '>=',
  tildeEqual: '~=',
  lesserEqual: '<=',
  greater: '>',
  lesser: '<',
  leftParenthesis: '(',
  rightParenthesis: ')',
  leftBrace: '{',
  rightBrace: '}',
  leftBracket: '[',
  rightBracket: ']',
  semicolon: ';',
  dobleColon: '::',
  colon: ':',
  comma: ',',
  hash: '#',
  ampersand: '&',
  tilde: '~',
  or: '|',
  leftShift: '<<',
  rightShift: '>>',
  doubleSlash: '//',
  spread: '...',
  doubleDot: '..',
  dot: '.',
});

module.exports = {lexer};