Is there a regex or other tool I can use to change a method call to a function call that encloses the previous expression?

Question

I'm working on making a change to a large C++ codebase where I need to change a method call to an equivalent function call, e.g. someExpression.foo() becomes bar(someExpression).

A few more examples of the sort of transformation I'm looking for:

(itemA + itemB).foo() becomes bar(itemA + itemB)
outerFunction(object->method(), arg2 + val, innerFunction(arg3)).foo() becomes bar(outerFunction(object->method(), arg2 + val, innerFunction(arg3)))

Basically, the expression proceeding the method call to foo() could be fairly complex. But foo() comes up a lot of times in my codebase, so I'm really hoping there's some way I can automate this change rather than having to laboriously edit everything manually.

Can this be done with a regex? Or is there another tool I can use to make this change?

https://en.wikipedia.org/wiki/VIATRA might provide it for you, but I'm not an expert on this. — lorro, Dec 01 '22 at 17:51
it probably can be done with a regex, finding all your edge cases will be fun though. — Alan Birtles, Dec 01 '22 at 18:03
It doesn't need to be perfect. Even if it only catches 80% of all of the instances of `foo()` it'd still be a big help. — Bri Bri, Dec 01 '22 at 18:13

score 0 · Answer 1 · answered Dec 01 '22 at 18:37

I've slapped together a regex that seems to work so far, based on the non-recursive parenthesis-balancing regex from this answer.

([^\s\(]*(?:\((?:[^)(]|\((?:[^)(]|\((?:[^)(]|\([^)(]*\))*\))*\))*\))?)\.foo\(\)

That won't match any valid expression proceeding .foo() but will match most of them. There may be bugs with this regex, but I haven't found any or hit any mismatches so far. And it contains a capture group that can be used for replacement, i.e.: bar(\1)

I'm going to leave this question open though because there are almost certainly better methods than this.

Is there a regex or other tool I can use to change a method call to a function call that encloses the previous expression?

1 Answers1