:sparkles: fix a local function
:fire: remove a comment
:sparkles: fix constructor of Lexer
:sparkles: fix to give location data to all tokens
:muscle: implement Lexer#unlex

  - remove token.revert
:sparkles: move code
:sparkles: fix how to use Marker
:sparkles: rename SCParser -> Parser

  - SC prefix shoule not be used outside SCClassLibrary