# File ext/tools/preproc.rb, line 63 def grammar(f, out) while line = f.gets case line when %r</\*%%%\*/> out << '#if 0' << $/ when %r</\*%c%\*/> out << '/*' << $/ when %r</\*%c> out << '*/' << $/ when %r</\*%> out << '#endif' << $/ when %r<%\*/> out << $/ when /\A%%/ out << '%%' << $/ return else out << line end end end