Selective auto-all for local bindings

[ezyang]

One style of writing code insists that the majority of functions be found in local bindings of where and let. While this keeps global namespace clean, it also means that -auto-all doesn't add cost centers to these bindings, and we have to manually instrument them. This is a pain. It would be really great if there was a magic SCC-ALL pragma which you could attach to a let or where keyword, which automatically SCC's all of the bindings in that block. You would specify a name, so that all of these local bindings could be qualified.

Maybe also an auto-all for (big) local bindings too? (Without any heuristics, that could get really big really fast! But it might be an easy step if the above is implemented.)

[igloo]

While being able to give a name would be nice, it isn't necessary, e.g. in

f = ...
    where g = let x = ... in ...

we could use names like "f", "f.g", "f.g.x".

[simonmar]

This is implemented in the profiling overhaul I'm working on.