YAPC::ASIA: Perl Program Repair Shop and Red Flags

It's hard to write great code, but it doesn't have to be hard to write good code. 'Red flags' are easy-to-see signs that you have an easy opportunity to make your code better. I'll show many red flags in real programs I've gathered and show easy ways to make these programs smaller, faster, and simpler to understand. Topics include: Grammars; recursive-descent parsing; trivial and basic parsers; concatenation and alternation of parsers; parsers for optional and repeated items; parsers for lists and blocks; parsers for complete expressions.