Full-context parsing executes predicates out-of-context

[antlr]

Full-context parsing executes predicates out-of-context

[sharwell]

If you pass the outer context into predTransition, it solves the problem of tracking the correct context for full-context prediction, but doesn't help local-context prediction. In the local-context case, the outer context never appears in the ATNConfig to use as a comparison basis. The depth tracking here is inexpensive and a single solution to both the full-context and local-context problems.

The unit test testJavaExpressions already tests this issue, strangely enough by passing when it should be failing. With the current implementation of LR rules and the current rules for prioritizing predicated alts over unpredicated alts, the following expression cannot be parsed correctly. With the issue corrected, the testJavaExpressions test will fail, highlighting the underlying issue with predicate precedence.

new T[((n-1) * x) + 1]