[SwiftLexicalLookup][GSoC] Add initial name lookup functionality

MAJKFL commented 2 weeks ago

This PR introduces ScopeSyntax protocol and some initial scope implementations.

The implementation works with tuples let (a, b) = (0, 0) and inline chaining let a = 0, b = 0.
Result of a lookup is an array of LookupName, an enum that distinguishes identifiers (extracted from variable declarations and/or closure/function parameters) from declarations (struct, class, actor, function etc.). We could possibly also add more cases that would serve as flags for the compiler later on.
Supports following scopes: code block, member block, for and while loops and closures.
Additionally, introduced result type assertion to assertLexicalScopeQuery test harness.
As discussed in #2696, this approach is centered around the syntax nodes using ScopeSyntax protocol to build hierarchy and uses position of the node used for lookup to determine availability of certain declarations (like in code block or if let).

DougGregor commented 3 days ago

@swift-ci please test

DougGregor commented 3 days ago

@swift-ci please test

DougGregor commented 3 days ago

@swift-ci please test Windows

DougGregor commented 2 days ago

@MAJKFL I've merged, but please look at Alex's comments above to address in a follow-up PR.

MAJKFL commented 2 days ago

Thanks for merging! Once I create a new PR with the suggested changes, I'll respond to the comments and link the fixes.

swiftlang / swift-syntax