go/types, types2: don't print function parameter names when showing type differences
Add a new flag 'paramNames' to typeWriter struct to control whether
function parameter names are written or not (set by default). Unset
it when we want the function signature w/o parameter names, e.g. when
showing two signatures that are not identical. This makes is much
easier to see the typw differences in the error message.
To avoid needing to provide yet another (rarely used) boolean parameter
to typeString, remove that function in favor of setting the paramNames
flag explicitly. Adjust the code in errors.go that used typeString; the
resulting code is also more efficient (fewer bytes.Buffer allocations).
While at it, rename the typeWriter 'debug' field to 'tpSubscripts'
because that is what it controls.
Add test case and adjusted existing expected output for existing tests.
Fixes #54942.
Change-Id: I625eae30c403c39ce89951b8ea6214d783c92c75
Reviewed-on: https://go-review.googlesource.com/c/go/+/430416 Reviewed-by: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Robert Griesemer <gri@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Robert Griesemer <gri@google.com>