TODO

Complete javascript and golang grammars
Add token helper that allows user to specify structure of tokens using rules other than strings and patterns
Allow language keywords to be specified inline, not as separate named rules.
Make separator character set configurable, not hard-coded to whitespace
Add special lexical behavior for indentation-aware languages
Return a useful error when grammar contains invalid regex patterns
Create working parser when grammar contains no error productions
Create working parser when grammar contains unused symbols
Implement Pager's Practical general method for reducing the size of the LR(1) parse table
Speed up grammar compilation
Implement the remainder of the incremental parsing algorithm: reuse parse tree after the edit
Create easy way to publish grammars as npm packages
Add simple selector engine for syntax trees
Make ordering of parse and lex tables deterministic, so that generated code doesn't keep changing on every commit