src

Go monorepo.
git clone git://code.dwrz.net/src
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s1010.go (1280B)

      1 package s1010
      2 
      3 import (
      4 	"go/ast"
      5 
      6 	"honnef.co/go/tools/analysis/code"
      7 	"honnef.co/go/tools/analysis/edit"
      8 	"honnef.co/go/tools/analysis/facts/generated"
      9 	"honnef.co/go/tools/analysis/lint"
     10 	"honnef.co/go/tools/analysis/report"
     11 	"honnef.co/go/tools/pattern"
     12 
     13 	"golang.org/x/tools/go/analysis"
     14 )
     15 
     16 var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
     17 	Analyzer: &analysis.Analyzer{
     18 		Name:     "S1010",
     19 		Run:      run,
     20 		Requires: append([]*analysis.Analyzer{generated.Analyzer}, code.RequiredAnalyzers...),
     21 	},
     22 	Doc: &lint.RawDocumentation{
     23 		Title: `Omit default slice index`,
     24 		Text: `When slicing, the second index defaults to the length of the value,
     25 making \'s[n:len(s)]\' and \'s[n:]\' equivalent.`,
     26 		Since:   "2017.1",
     27 		MergeIf: lint.MergeIfAny,
     28 	},
     29 })
     30 
     31 var Analyzer = SCAnalyzer.Analyzer
     32 
     33 var checkSlicingQ = pattern.MustParse(`(SliceExpr x@(Object _) low (CallExpr (Builtin "len") [x]) nil)`)
     34 
     35 func run(pass *analysis.Pass) (any, error) {
     36 	for node := range code.Matches(pass, checkSlicingQ) {
     37 		expr := node.(*ast.SliceExpr)
     38 		report.Report(pass, expr.High,
     39 			"should omit second index in slice, s[a:len(s)] is identical to s[a:]",
     40 			report.FilterGenerated(),
     41 			report.Fixes(edit.Fix("Simplify slice expression", edit.Delete(expr.High))))
     42 	}
     43 	return nil, nil
     44 }