class SyntaxTree::Parser

def on_backref(value)

on_backref: (String value) -> Backref
:call-seq: 
def on_backref(value)
  Backref.new(
    value: value,
    location:
      Location.token(
        line: lineno,
        char: char_pos,
        column: current_column,
        size: value.size
      )
  )
end