Use Parser instead of Ripper
Implement recursive search
Minor fix
Support method call [wip]

Block arguments are not supported.
Support method call with block
Minor fix
Support statements generally
Show here document
Minor fix
Extract some code to method
Add tests
Support heredocs enclosed in parentheses
Support heredocs represented as :str
Minor fix
`search` calls a passed block only for Parser::AST::Node instance
Minor fix
Add test for nested heredocs
Support heredoc in string literal

Add `return_when_finding` option to `search`
Reimplement highlight in Ruby (not semantic)
Fix bug in `search`

`return_when_finding` param wasn't passed in reccuring.