Take the 2-minute tour ×  I have to perform a large change to a
codebase that consists of a handful of different types of
changes that need to be applied in hundreds of different
locations, spread out over hundreds of thousands of lines.  I
have an idea for a tool that can help me with this, but as I'm
sure I'm not the only one with this idea, I wonder if it's
already been written.  Let me outline how it would work:    •
First, a bit like grep with context, it would collect a set of
"interesting" chunks of code based on a regular expression;
there may be thousands of these locations.   • Then, let me
iterate through chunks, marking each in turn as Interesting or
Uninteresting. This is basically automating as much as possible
of the manual job of whittling down potential change locations
to actual change locations.   • Finally, let me apply a
transformation (e.g. sed-style substitution) to all selected
Interesting locations.  Does this tool already exist?  I'm
thinking of writing this tool myself if I can't fi