Comby - A code rewrite tool for structural search and replace that supports every language

Comby provides a lightweight way of matching syntactic structures of a program’s parse tree, like expressions and function blocks. Comby is language-aware and understands basic syntax of code, strings, and comment syntax in many languages.

Comby works by defining general parsers for code constructs like balanced (...), {...}, and [...], as well as string literals and comments. It doesn’t implement a full parser for every language, but rather a more general grammar so that it works on a lot of languages (just like regular expressions work on the text of every language).