flbulgarelli/language-ruby

language-ruby

Haskell parser for the Ruby 2.6 Language. Project structure is loosely based https://github.com/erikd/language-javascript, lexer is based on https://github.com/bjpop/language-python and parser is based on https://github.com/whitequark/parser.

Building

$ stack build

Running tests

$ stack test --file-watch --fast

Debugging Grammar

$ happy src/Parser.y -dai

Nodes naming

AST Nodes naming is the same as whitequark/parser's, with the following notable exceptions and changes:

• CamelCase is used instead of snake_case. E.g.:
  • (Str "foo") instead of s(:str, "foo")
  • (BackRef "$&") instead of s(:back_ref, :$&)
• Special __ variables have being completly renamed and are not being processed:
  • File instead of __FILE__
  • Encoding instead of __ENCODING__
  • Line instead of __LINE__
• Varargs are replaced by lists:
  • (Begin [RInt 4, RInt 5]) instead of s(:begin, s(:int, 4), s(:int, 5))
• Ruby datatypes are prefixed with an in order to avoid collisions. E.g.:
  • RInt instead of int
  • RFloat instead of float

Caveats

1. Parser acts as if run with Parser::Builders::Default.emit_procarg0 = false and thus makes no distinction between f {|a|} and f{|a,|} since making such a distinction for only blocks with a single parameter seems odd.

Pending tasks

This project is just an on-going progress:

• ✔️ Grammar is mostly finished
• ❎ Lexer is incompletle
• ❎ Tree builder and AST is mostly unimplemented
• ❎ Happy build times are slow which is cumbersome for development, I should check bjpop/language-python#41. On the meanwhile, just comment grammar rules that are not being developed.