# File ext/tools/preproc.rb, line 41 def prelude(f, out) while line = f.gets case line when %r</\*%%%\*/> out << '/*' << $/ when %r</\*%> out << '*/' << $/ when %r<%\*/> out << $/ when /\A%%/ out << '%%' << $/ return when /\A%token/ out << line.sub(/<\w+>/, '<val>') when /\A%type/ out << line.sub(/<\w+>/, '<val>') else out << line end end end