class_docstr: A Scheme lexer.
  
  This parser is checked with pastes from the LISP pastebin
  at http://paste.lisp.org/ to cover as much syntax as possible.
  
  It supports the full Scheme syntax as defined in R5RS.
  
  .. versionadded:: 0.6
code: def decimal_cb(self, match):
      if "." in match.group():
          token_type = Number.Float  # includes [+-](inf|nan).0
      else:
          token_type = Number.Integer
      yield match.start(), token_type, match.group()
  
imports: import re
  from pygments.lexer import RegexLexer, include, bygroups, words, default
  from pygments.token import Text, Comment, Operator, Keyword, Name, String, Number, Punctuation, Literal, Error, Whitespace
  from pygments.lexers.python import PythonLexer
  from pygments.lexers._scheme_builtins import scheme_keywords, scheme_builtins
label_desc: Use image node_id 2 for calling the SchemeLexer obj's underlying member method code with example usage: obj.decimal_cb(match) without return types