Comby - Structural code search and replace for every language
1–10 of 26 posts
Re: Comby - Structural code search and replace for every language
#2I mocked up a prototype for something similar to this using TreeSitter and its query language the other day for some heavy refactoring I had to do. This looks like a really cool project, will have to try it out!
Re: Comby - Structural code search and replace for every language
#3Superb tool. I used Comby to create a massive (3000+ changes) PR in which I ported JS type annotations into TS typings.
Re: Comby - Structural code search and replace for every language
#4I believe Sourcegraph uses Comby under the hood to an extent for structural matching as well!
Re: Comby - Structural code search and replace for every language
#5Okay wow. I didn't tools like this existed! There's been more than once where I've found myself in a situation like "find all code like this, change if this, delete if this". Regex can only get you so far.
Does someone know if this or something similar is available as a VSCode extension? It'd be fun to make one if not!
Re: Comby - Structural code search and replace for every language
#6License?
Also, how does it compare to Coccinelle?
Re: Comby - Structural code search and replace for every language
#7License? Also, how does it compare to Coccinelle?
License seems to be apache V2, see https://github.com/comby-tools/comby/blob/master/LICENSE.
They have a comparison section in their faq (https://comby.dev/docs/faq):
"Coccinelle uses a declarative syntax for matching constructs like function calls, if-statements, expression blocks, and so on for the C language. Some notable differences are that Coccinelle provides a patch-like format to express transformations (handy when you want to inline smaller changes in a broader context) and metavariable declarations (handy for developing and organizing more sophisticated patterns). For an example, see the file null_ref.cocci. Coccinelle works only for the C language, and may struggle to parse files that contain non-standard C constructs, like GCC inline assembly. Recent Coccinelle work has started expanding support for Java. In contrast, Comby’s syntax targets a wide range of languages and is more robust to matching patterns in the presence of unrecognized constructs. Comby is more suited to writing quick find-replace patterns for languages beyond C, and works well on C languages too."
Re: Comby - Structural code search and replace for every language
#8This looks a lot like https://semgrep.dev/
Interesting that they are both largely OCaml.
Re: Comby - Structural code search and replace for every language
#9This looks a lot like https://semgrep.dev/ Interesting that they are both largely OCaml.
ML style languages handle tree structures and traversal so well, I'm wondering if that's a large reason for using it.
Re: Comby - Structural code search and replace for every language
#10A more interesting comparison than with Coccinelle is with semgrep (https://semgrep.dev/) since it also supports semantic/structural pattern matching over a number of languages, but also adds in a bunch of Boolean logic into the mix, as well as some more advanced semantic features like constant propagation.
Curious whether the teams behind these tools are aware of each other? I suppose it's unlikely that they're not.