gulp-antlr4-newer

Gulp plugin working in combination with gulp-antlr4 to not recreate parser files when grammar is untouched

• Usage
• License

Usage

gulp-antlr4-newer gulp plugin filters .g4` grammar files according to timestamps. If they are newer than the corresponding parser or lexer files, they are passed through. Otherwise, they are removed from the stream.

import gulp from 'gulp'
import antlr4 from 'gulp-antlr4';
import newer from 'gulp-antlr4-newer';

const grammarGlob = 'grammars/**/*.g4';
const parserDir = 'build/parsers';

gulp.task('make:parser', () => {
  // newer compares by default parserDir/*Parser.js files to parent
  // grammar files. newer expects an option as an object precising the
  // same parserDIr passed to anltr4.
  // When the grammar has been touched, then newer let it through so that
  // antlr4 will regenerate the parser files.

  return gulp.src(grammarGlob, {
    base: process.cwd(),
  })
    .pipe(newer({parserDir}))
    .pipe(antlr4(parserDir));
});

gulp.task('make:lexer', () => {
  // In case of lexer grammars, newer will compare parserDir/*Lexer.js files
  // to parent grammar files. Option {lexer: true} must be specified, because
  // missing *Parser.js would always cause the Lexer files to be regenerated

  return gulp.src(grammarGlob, {
    base: process.cwd(),
  })
    .pipe(newer({parserDir, lexer: true}))
    .pipe(antlr4(parserDir));
});

gulp.task('default', () => {
  // If a string is passed as option, it is considered to be parserDir

  return gulp.src(grammarGlob, {
    base: process.cwd(),
  })
    .pipe(newer(parserDir))
    .pipe(antlr4(parserDir));
});

License

gulp-antlr4-newer is MIT licensed.

© 2017 Jason Lenoble