Use SkipTrivia instead of GetRangeOfTokenAtPosition where possible #2089
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Pull Request Overview
This PR optimizes two call sites by replacing GetRangeOfTokenAtPosition().Pos() with SkipTrivia() to avoid unnecessary token scanning. The function GetRangeOfTokenAtPosition internally calls SkipTrivia and then scans a full token to compute a range, which is wasteful when only the position after trivia is needed.
Key Changes
- Replaced
scanner.GetRangeOfTokenAtPosition(file, lastToken.End()).Pos()withscanner.SkipTrivia(file.Text(), lastToken.End())in semicolon detection logic - Replaced
scanner.GetRangeOfTokenAtPosition(sourceFile, node.Pos()).Pos()withscanner.SkipTrivia(sourceFile.Text(), node.Pos())inwithstatement error reporting
Reviewed Changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| internal/ls/lsutil/utilities.go | Optimized ProbablyUsesSemicolons to skip trivia directly when determining line positions for semicolon inference |
| internal/checker/checker.go | Optimized checkWithStatement to skip trivia directly when computing error span start position |
| sourceFile := ast.GetSourceFileOfNode(node) | ||
| if !c.hasParseDiagnostics(sourceFile) { | ||
| start := scanner.GetRangeOfTokenAtPosition(sourceFile, node.Pos()).Pos() | ||
| start := scanner.SkipTrivia(sourceFile.Text(), node.Pos()) |
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We're going to be so much faster when erroring on with statements now. 😎
DanielRosenwasser
approved these changes
Nov 14, 2025
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@DanielRosenwasser noticed I made this same mistake.
GetRangeOfTokenAtPositionimplicitly skips trivia, but then also scans a token. This is wasteful for callers that could just skip trivia.