Port global completions

[gabritto]

This PR ports global completions, a.k.a. completions you get from symbols collected by tryGetGlobalSymbols.

[Copilot]

Pull Request Overview

This PR ports global completions by updating the logic to use the symbols gathered via tryGetGlobalSymbols. Key changes include:

• Introducing the use of maps.Copy in scanner initialization.
• Refactoring utility functions (e.g. in ls/utilities.go and symbol_display.go) and renaming some checker functions to their exported forms.
• Adding a new test setup for processing marker ranges.

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/scanner/scanner.go	Uses maps.Copy to copy token text mappings during initialization.
internal/ls/utilities.go	Adds and refactors helper functions for token scanning and child traversal.
internal/ls/symbol_display.go	Modifies the logic determining local variable/function context.
internal/ls/testsetup.go	Introduces new test setup and marker parsing functions.
internal/checker/*	Renames several internal checker functions to exported forms and updates calls accordingly.
internal/astnav/tokens.go, internal/ast/*	Adjustments to AST utilities and token visitor functions to support new patterns.

Comments suppressed due to low confidence (2)

internal/ls/symbol_display.go:290

• The change from using 'continue' to 'break' in the loop over parent nodes may alter the original iteration logic used to determine local variable/function context. Please verify that breaking out of the loop upon encountering a SourceFile or ModuleBlock is the intended behavior for all cases.

for ; !ast.IsFunctionBlock(parent); parent = parent.Parent { if parent.Kind == ast.KindSourceFile || parent.Kind == ast.KindModuleBlock { break } }

internal/scanner/scanner.go:6

• The introduction of maps.Copy to copy token mappings is a clean use of the new Go functionality; please ensure that our build and runtime environments support the required Go version.

import (
	"fmt"
	"iter"
	"maps"
	"strconv"

[andrewbranch]

Are there any notable deviations from Strada that should get special attention in a code review?

[gabritto]

Are there any notable deviations from Strada that should get special attention in a code review?

Good question. I don't think there are any for this PR, at least not that I can think of. I'll try to keep that in mind and call it out on future PRs.

[jakebailey]

I think that something must be missing from the response; I'm doing global completions and VS Code is saying that there aren't any matches:

[jakebailey]

Nit, but maybe we should just declare a new one and keep the existing calls internal to reduce the diff? Maybe it's pointless.

[jakebailey]

Though it is a lot of lines in this PR...

[gabritto]

I think that something must be missing from the response; I'm doing global completions and VS Code is saying that there aren't any matches:

Yeah, for some reason the insert/replace positions are messed up I think, I don't know yet where the positions go wrong. I'll debug and update with a fix tomorrow.

Update: fixed by #866.

[jakebailey]

Before we merge this, I believe that @ahejlsberg wanted to see about not renaming the methods but instead declaring exported wrappers in a new file in the checker package. Would probably be good to do that now instead of churning back and forth.