Patterns may need to be visited twice during analysis: once to
determine a type schema, and a second type to resolve the pattern
match. Previously, the shared TypeAnalyzer had just a single
`dispatchPattern` method, so it had to create temporary objects to
record the structure of the patterns between the two visits. Now,
there are two dispatch methods: `dispatchPatternSchema` and
`dispatchPattern`. This avoids the creation of a bunch of temporary
objects and makes the design much simpler.
(Based on an idea from Brian Wilkerson)
Change-Id: If10b6b7fb578594c3f660baa55d7e28123652638
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/260282
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
Paul Berry
8da75ede06