[for reference] all work done which is not in original repo

[GerHobbelt]

Co-exists with zaach/jison#338.

Features / Fixes / Changes

• [to be edited]
• engine adds stop-gap check at lexer runtime to prevent user-programmer mistakes from causing obscure/hard-to-diagnose internal lexer crashes (#19) - see SHA-1: 57dd80420ed3c654a86e60b693d3714755d22fa7 (Check whether a sane condition has been pushed before: this makes the lexer robust against user-programmer bugs such as #19)
• fixes:
  • #9 + #10 (undefined start conditions)
  • #11 (faster exec of simple return statements via lookup table)
  • #15 (CLI to lexer options: now its own CLI and jison CLI pass the options (filtered) to the lexer)
  • #16 (no input location info passed to error: now lexer parseError receives a hash info object with location info and other context at the time of error, just like we already did in the parser)
  • #16 + #17 (recursive lex() call === stack overflow crash)
  • #19
  • #23 (feed the API lexer rules' action code in the form of JavaScript arrow functions instead of classic JavaScript functions (function () { return 'TOKEN'; }) or action code string ('return "TOKEN";')