This IDE refactoring tool clearly doesn't understand the language either, or it wouldn't screw up your code (as they clearly warn you it might). Personally, I'

This IDE refactoring tool clearly doesn't understand the language either, or it wouldn't screw up your code (as they clearly warn you it might). Personally, I'd much rather use a simple tool (like sed), with reliable, deterministic results, than something that's right "99% of the time". Sure, it tries to spot edge cases and flag them up to you, but if it's wrong some of the time, who's to say that it won't fail to spot an edge case 1% of the time too? So if it fails 1% of the time, and it fails to realise the problem in 1% of those cases, then it's introducing subtle bugs one time in every 10,000?? The very idea gives me cold shivers. Note: if they "improve" the tool so that it's right 99.9% of the time, then they've only made the situation worse. Now the bugs only crop up one time in 1,000,000 - and now they are even more subtle. tl;dr - a refactoring tool is 100% reliable, or useless. There's no in-between case.