bench.js

#!/usr/bin/env node

const {BufferedRegExpScanner, Dialect, TokenDefinition} = require('./dist')
// import {BufferedRegExpScanner, Dialect, TokenDefinition} from './src'

const length = 100000
const subject = Array(length).fill(`if (this) then {that}`, 0, length).join('\n')

const myLang = new Dialect([
  new TokenDefinition('IF', String.raw`if`),
  new TokenDefinition('THIS', String.raw`this`),
  new TokenDefinition('THEN', String.raw`then`),
  new TokenDefinition('SPACE', String.raw`\s+`),
  new TokenDefinition('LPAREN', String.raw`\(`),
  new TokenDefinition('RPAREN', String.raw`\)`),
  new TokenDefinition('LBRACE', String.raw`\{`),
  new TokenDefinition('RBRACE', String.raw`\}`),
  new TokenDefinition('VAR', String.raw`\w+`),
])

let scanner = new BufferedRegExpScanner(subject)

console.log(`scanning ${Math.floor(subject.length / 1024)}KB equivalent file`)

const t0 = Date.now()
for (const _tok of scanner.generateTokensUsingDialect(myLang)) {
  /* nada */
}
console.log(`raw scan: ${Date.now() - t0}ms`)

const tokens = []
scanner = new BufferedRegExpScanner(subject)
const t1 = Date.now()
for (const tok of scanner.generateTokensUsingDialect(myLang)) {
  tokens.push(tok)
}
console.log(`scan: ${Date.now() - t1}ms`)

const t2 = Date.now()
tokens[Math.floor(length / 2)].line
console.log(`first lineno: ${Date.now() - t2}ms`)

const t3 = Date.now()
tokens[Math.floor(length / 2)].line
console.log(`second lineno: ${Date.now() - t3}ms`)


/* eslint no-console: off */