redparse

https://github.com/coatl/redparse

RedParse is a ruby parser (and parser-compiler) written in pure ruby. Instead of YACC or ANTLR, it's parse tool is a home-brewed language. (The tool is (at least) LALR(1)-equivalent and the 'parse language' is pretty nice, even in it's current form.) My intent is to have a completely correct parser for ruby, in 100% ruby. And I think I've more or less succeeded. Aside from some fairly minor quibbles (see below), RedParse can parse all known ruby 1.8 and 1.9 constructions correctly. Input text may be encoded in ascii, binary, utf-8, iso-8859-1, and the euc-* family of encodings. Sjis is not yet supported.