tree c0a083aa0d0534c9ab352d09b37c1ea602c0222b
parent ff265bb5ae1b5b13d71d553a0ee02115294093b4
author Paul Berry <paulberry@google.com> 1550842786 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1550842786 +0000

Normalize expression precedence between analyzer and front_end.

Several places in the analyzer and the analysis server were using
hardcoded integers to represent precedence, rather than referring to
constants defined in the front_end.  This led to some subtle
off-by-one errors, because the old analyzer convention (prior to
integration with the front_end parser) used 0 to represent the lowest
precedence of an expression (and -1000 to represent the precedence of
non-expressions), whereas the front_end convention is for 1 to
represent the lowest precedence of an expression.  As far as I can
tell there was no user visible impact, but it made it very difficult
to reason about operator precedence.

This CL updates the analyzer and the analysis server so that they
don't hardcode any precedence values; instead they refer to named
constants in the front end.

In a follow-up CL I'll reduce some hardcoded precedence numbers in the
front end itself.

Change-Id: Id3869afeb83042cc7d6630a0a4a0533a07058736
Reviewed-on: https://dart-review.googlesource.com/c/93964
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>