Then `isClassExpensive?` was being invoked too often. In some
benchmarks the performance hit was substantial. For example,
in the new test `state8.lean`. The runtime on my machine went from 2s
to 0.76s.
We annotate patterns with the corresponding `Syntax` during
elaboration, and do not populate the info tree. Reason: the set of
pattern variables is not known during pattern elaboration.
This fix may impact performance. Note that we don't need to flush the
cache if we are "adding" stuff to the environment. We only need to
flush the caches if the change is not monotonic. BTW, most of the
changes are monotonic. I think this is why we did not hit this bug before.
We may also move all these caches to an environment extension. It is
an easy way to make sure we preserve the cache when extending the
environment.
I tried a few benchmarks and did not notice a significant difference.
cc @kha @gebner
fixes#1051
We don't use the following hack anymore:
- /- HACK: `fvarId` is not in the scope of `mvarId`
- If this generates problems in the future, we should update the metavariable declarations. -/
- assignExprMVar mvarId (mkFVar fvarId)
This hack was corrupting the `InfoTree`.
