all: use strings.SplitSeq/FieldSeq

kolyshkin · gopherbot · commit ba63d1303f9a · 2025-09-12T06:16:04.000-07:00
Replace Split in "for range strings.Split(...)" by go1.24's more efficient SplitSeq, or Fields with FieldSeq. Generated by modernize -fix -test -category stringsseq ./... (with a few minor edits on top to remove intermediate vars). Change-Id: Ifd616ccec14e7fe0a743d427e02f44b3297a273c Reviewed-on: https://go-review.googlesource.com/c/tools/+/703075 Auto-Submit: Kirill Kolyshkin <kolyshkin@gmail.com> Reviewed-by: Alan Donovan <adonovan@google.com> Reviewed-by: Robert Findley <rfindley@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/cmd/bundle/main.go b/cmd/bundle/main.go
@@ -241,7 +241,7 @@ func bundle(src, dst, dstpkg, prefix, buildTags string) ([]byte, error) {
 	// Concatenate package comments from all files...
 	for _, f := range pkg.Syntax {
 		if doc := f.Doc.Text(); strings.TrimSpace(doc) != "" {
-			for _, line := range strings.Split(doc, "\n") {
+			for line := range strings.SplitSeq(doc, "\n") {
 				fmt.Fprintf(&out, "// %s\n", line)
 			}
 		}
diff --git a/cmd/compilebench/main.go b/cmd/compilebench/main.go
@@ -511,7 +511,7 @@ func runBuildCmd(name string, count int, dir, tool string, args []string) error
 		if err != nil {
 			log.Print("cannot find memory profile after compilation")
 		}
-		for _, line := range strings.Split(string(out), "\n") {
+		for line := range strings.SplitSeq(string(out), "\n") {
 			f := strings.Fields(line)
 			if len(f) < 4 || f[0] != "#" || f[2] != "=" {
 				continue
diff --git a/cmd/digraph/digraph_test.go b/cmd/digraph/digraph_test.go
@@ -252,7 +252,7 @@ func TestSomepath(t *testing.T) {
 			got = strings.Join(lines[1:], "\n")
 
 			var oneMatch bool
-			for _, want := range strings.Split(test.wantAnyOf, "|") {
+			for want := range strings.SplitSeq(test.wantAnyOf, "|") {
 				if got == want {
 					oneMatch = true
 				}
diff --git a/cmd/fiximports/main.go b/cmd/fiximports/main.go
@@ -175,7 +175,7 @@ func fiximports(packages ...string) bool {
 		matchPrefix bool
 	}
 	var replace []replaceItem
-	for _, pair := range strings.Split(*replaceFlag, ",") {
+	for pair := range strings.SplitSeq(*replaceFlag, ",") {
 		if pair == "" {
 			continue
 		}
diff --git a/cmd/go-contrib-init/contrib.go b/cmd/go-contrib-init/contrib.go
@@ -191,7 +191,7 @@ func checkGitOrigin() {
 		log.Fatalf("Error running git remote -v: %v", msg)
 	}
 	matches := 0
-	for _, line := range strings.Split(string(remotes), "\n") {
+	for line := range strings.SplitSeq(string(remotes), "\n") {
 		line = strings.TrimSpace(line)
 		if !strings.HasPrefix(line, "origin") {
 			continue
diff --git a/cmd/html2article/conv.go b/cmd/html2article/conv.go
@@ -132,7 +132,7 @@ func isBoldTitle(s string) bool {
 }
 
 func indent(buf *bytes.Buffer, s string) {
-	for _, l := range strings.Split(s, "\n") {
+	for l := range strings.SplitSeq(s, "\n") {
 		if l != "" {
 			buf.WriteByte('\t')
 			buf.WriteString(l)
@@ -143,7 +143,7 @@ func indent(buf *bytes.Buffer, s string) {
 
 func unwrap(buf *bytes.Buffer, s string) {
 	var cont bool
-	for _, l := range strings.Split(s, "\n") {
+	for l := range strings.SplitSeq(s, "\n") {
 		l = strings.TrimSpace(l)
 		if len(l) == 0 {
 			if cont {
diff --git a/cmd/present2md/main.go b/cmd/present2md/main.go
@@ -200,7 +200,7 @@ func printSectionBody(file string, depth int, w *bytes.Buffer, elems []present.E
 				lines = lines[1:]
 			}
 			if elem.Pre {
-				for _, line := range strings.Split(strings.TrimRight(elem.Raw, "\n"), "\n") {
+				for line := range strings.SplitSeq(strings.TrimRight(elem.Raw, "\n"), "\n") {
 					if line == "" {
 						fmt.Fprintf(w, "\n")
 					} else {
diff --git a/cmd/signature-fuzzer/internal/fuzz-generator/generator.go b/cmd/signature-fuzzer/internal/fuzz-generator/generator.go
@@ -409,8 +409,7 @@ func ParseMaskString(arg string, tag string) (map[int]int, error) {
 	}
 	verb(1, "%s mask is %s", tag, arg)
 	m := make(map[int]int)
-	ss := strings.Split(arg, ":")
-	for _, s := range ss {
+	for s := range strings.SplitSeq(arg, ":") {
 		if strings.Contains(s, "-") {
 			rng := strings.Split(s, "-")
 			if len(rng) != 2 {
diff --git a/go/analysis/analysistest/analysistest.go b/go/analysis/analysistest/analysistest.go
@@ -590,7 +590,7 @@ func check(t Testing, gopath string, act *checker.Action) {
 		}
 		filename := sanitize(gopath, filename)
 		linenum := 0
-		for _, line := range strings.Split(string(data), "\n") {
+		for line := range strings.SplitSeq(string(data), "\n") {
 			linenum++
 
 			// Hack: treat a comment of the form "//...// want..."
diff --git a/go/analysis/internal/checker/fix_test.go b/go/analysis/internal/checker/fix_test.go
@@ -338,7 +338,7 @@ func TestScript(t *testing.T) {
 
 				case "skip":
 					config := fmt.Sprintf("GOOS=%s GOARCH=%s", runtime.GOOS, runtime.GOARCH)
-					for _, word := range strings.Fields(rest) {
+					for word := range strings.FieldsSeq(rest) {
 						if strings.Contains(config, word) {
 							t.Skip(word)
 						}
diff --git a/go/analysis/passes/asmdecl/asmdecl.go b/go/analysis/passes/asmdecl/asmdecl.go
@@ -237,7 +237,7 @@ Files:
 					// so accumulate them all and then prefer the one that
 					// matches build.Default.GOARCH.
 					var archCandidates []*asmArch
-					for _, fld := range strings.Fields(m[1]) {
+					for fld := range strings.FieldsSeq(m[1]) {
 						for _, a := range arches {
 							if a.name == fld {
 								archCandidates = append(archCandidates, a)
diff --git a/go/analysis/passes/buildtag/buildtag.go b/go/analysis/passes/buildtag/buildtag.go
@@ -298,7 +298,7 @@ func (check *checker) plusBuildLine(pos token.Pos, line string) {
 	fields := strings.Fields(line[len("//"):])
 	// IsPlusBuildConstraint check above implies fields[0] == "+build"
 	for _, arg := range fields[1:] {
-		for _, elem := range strings.Split(arg, ",") {
+		for elem := range strings.SplitSeq(arg, ",") {
 			if strings.HasPrefix(elem, "!!") {
 				check.pass.Reportf(pos, "invalid double negative in build constraint: %s", arg)
 				check.crossCheck = false
diff --git a/go/analysis/passes/printf/printf.go b/go/analysis/passes/printf/printf.go
@@ -992,7 +992,7 @@ func (ss stringSet) String() string {
 }
 
 func (ss stringSet) Set(flag string) error {
-	for _, name := range strings.Split(flag, ",") {
+	for name := range strings.SplitSeq(flag, ",") {
 		if len(name) == 0 {
 			return fmt.Errorf("empty string")
 		}
diff --git a/go/analysis/passes/unusedresult/unusedresult.go b/go/analysis/passes/unusedresult/unusedresult.go
@@ -188,7 +188,7 @@ func (ss *stringSetFlag) String() string {
 func (ss *stringSetFlag) Set(s string) error {
 	m := make(map[string]bool) // clobber previous value
 	if s != "" {
-		for _, name := range strings.Split(s, ",") {
+		for name := range strings.SplitSeq(s, ",") {
 			if name == "" {
 				continue // TODO: report error? proceed?
 			}
diff --git a/go/buildutil/tags.go b/go/buildutil/tags.go
@@ -43,7 +43,7 @@ func (v *TagsFlag) Set(s string) error {
 
 	// Starting in Go 1.13, the -tags flag is a comma-separated list of build tags.
 	*v = []string{}
-	for _, s := range strings.Split(s, ",") {
+	for s := range strings.SplitSeq(s, ",") {
 		if s != "" {
 			*v = append(*v, s)
 		}
diff --git a/go/callgraph/rta/rta_test.go b/go/callgraph/rta/rta_test.go
@@ -120,7 +120,7 @@ func check(t *testing.T, f *ast.File, pkg *ssa.Package, res *rta.Result) {
 		wantReachable = make(map[string]bool)
 		wantRtype     = make(map[string]bool)
 	)
-	for _, line := range strings.Split(want, "\n") {
+	for line := range strings.SplitSeq(want, "\n") {
 		linenum++
 		orig := line
 		bad := func() {
diff --git a/go/ssa/interp/rangefunc_test.go b/go/ssa/interp/rangefunc_test.go
@@ -108,7 +108,7 @@ func TestRangeFunc(t *testing.T) {
 		},
 	}
 	got := make(map[string][]string)
-	for _, ln := range strings.Split(out, "\n") {
+	for ln := range strings.SplitSeq(out, "\n") {
 		if ind := strings.Index(ln, " \t "); ind >= 0 {
 			n, m := ln[:ind], ln[ind+3:]
 			got[n] = append(got[n], m)
diff --git a/internal/analysisinternal/extractdoc.go b/internal/analysisinternal/extractdoc.go
@@ -97,7 +97,7 @@ func ExtractDoc(content, name string) (string, error) {
 	if f.Doc == nil {
 		return "", fmt.Errorf("Go source file has no package doc comment")
 	}
-	for _, section := range strings.Split(f.Doc.Text(), "\n# ") {
+	for section := range strings.SplitSeq(f.Doc.Text(), "\n# ") {
 		if body := strings.TrimPrefix(section, "Analyzer "+name); body != section &&
 			body != "" &&
 			body[0] == '\r' || body[0] == '\n' {
diff --git a/internal/astutil/comment.go b/internal/astutil/comment.go
@@ -15,7 +15,7 @@ import (
 // https://go.dev/wiki/Deprecated, or "" if the documented symbol is not
 // deprecated.
 func Deprecation(doc *ast.CommentGroup) string {
-	for _, p := range strings.Split(doc.Text(), "\n\n") {
+	for p := range strings.SplitSeq(doc.Text(), "\n\n") {
 		// There is still some ambiguity for deprecation message. This function
 		// only returns the paragraph introduced by "Deprecated: ". More
 		// information related to the deprecation may follow in additional
diff --git a/internal/goroot/importcfg.go b/internal/goroot/importcfg.go
@@ -51,7 +51,7 @@ func PkgfileMap() (map[string]string, error) {
 		if err != nil {
 			stdlibPkgfileErr = err
 		}
-		for _, line := range strings.Split(string(output), "\n") {
+		for line := range strings.SplitSeq(string(output), "\n") {
 			if line == "" {
 				continue
 			}
diff --git a/internal/imports/fix.go b/internal/imports/fix.go
@@ -42,7 +42,7 @@ var importToGroup = []func(localPrefix, importPath string) (num int, ok bool){
 		if localPrefix == "" {
 			return
 		}
-		for _, p := range strings.Split(localPrefix, ",") {
+		for p := range strings.SplitSeq(localPrefix, ",") {
 			if strings.HasPrefix(importPath, p) || strings.TrimSuffix(p, "/") == importPath {
 				return 3, true
 			}
diff --git a/internal/mcp/internal/util/util.go b/internal/mcp/internal/util/util.go
@@ -67,7 +67,7 @@ func FieldJSONInfo(f reflect.StructField) JSONInfo {
 		}
 		if len(rest) > 0 {
 			info.Settings = map[string]bool{}
-			for _, s := range strings.Split(rest, ",") {
+			for s := range strings.SplitSeq(rest, ",") {
 				info.Settings[s] = true
 			}
 		}
diff --git a/internal/modindex/symbols.go b/internal/modindex/symbols.go
@@ -206,8 +206,7 @@ func isDeprecated(doc *ast.CommentGroup) bool {
 	// go.dev/wiki/Deprecated Paragraph starting 'Deprecated:'
 	// This code fails for /* Deprecated: */, but it's the code from
 	// gopls/internal/analysis/deprecated
-	lines := strings.Split(doc.Text(), "\n\n")
-	for _, line := range lines {
+	for line := range strings.SplitSeq(doc.Text(), "\n\n") {
 		if strings.HasPrefix(line, "Deprecated:") {
 			return true
 		}
diff --git a/internal/refactor/inline/free_test.go b/internal/refactor/inline/free_test.go
@@ -215,7 +215,7 @@ func TestFreeishNames(t *testing.T) {
 				n := f.Decls[0].(*ast.FuncDecl).Body
 				got := map[string]bool{}
 				want := map[string]bool{}
-				for _, n := range strings.Fields(test.want) {
+				for n := range strings.FieldsSeq(test.want) {
 					want[n] = true
 				}
 
diff --git a/internal/testenv/testenv.go b/internal/testenv/testenv.go
@@ -530,7 +530,7 @@ func NeedsGoExperiment(t testing.TB, flag string) {
 
 	goexp := os.Getenv("GOEXPERIMENT")
 	set := false
-	for _, f := range strings.Split(goexp, ",") {
+	for f := range strings.SplitSeq(goexp, ",") {
 		if f == "" {
 			continue
 		}

Original file line number	Diff line number	Diff line change
`@@ -241,7 +241,7 @@ func bundle(src, dst, dstpkg, prefix, buildTags string) ([]byte, error) {`
`241`	`241`	`// Concatenate package comments from all files...`
`242`	`242`	`for _, f := range pkg.Syntax {`
`243`	`243`	`if doc := f.Doc.Text(); strings.TrimSpace(doc) != "" {`
`244`		`- for _, line := range strings.Split(doc, "\n") {`
	`244`	`+ for line := range strings.SplitSeq(doc, "\n") {`
`245`	`245`	`fmt.Fprintf(&out, "// %s\n", line)`
`246`	`246`	`}`
`247`	`247`	`}`
Original file line number	Diff line number	Diff line change
`@@ -511,7 +511,7 @@ func runBuildCmd(name string, count int, dir, tool string, args []string) error`
`511`	`511`	`if err != nil {`
`512`	`512`	`log.Print("cannot find memory profile after compilation")`
`513`	`513`	`}`
`514`		`- for _, line := range strings.Split(string(out), "\n") {`
	`514`	`+ for line := range strings.SplitSeq(string(out), "\n") {`
`515`	`515`	`f := strings.Fields(line)`
`516`	`516`	`if len(f) < 4 \|\| f[0] != "#" \|\| f[2] != "=" {`
`517`	`517`	`continue`
Original file line number	Diff line number	Diff line change
`@@ -252,7 +252,7 @@ func TestSomepath(t *testing.T) {`
`252`	`252`	`got = strings.Join(lines[1:], "\n")`
`253`	`253`
`254`	`254`	`var oneMatch bool`
`255`		`- for _, want := range strings.Split(test.wantAnyOf, "\|") {`
	`255`	`+ for want := range strings.SplitSeq(test.wantAnyOf, "\|") {`
`256`	`256`	`if got == want {`
`257`	`257`	`oneMatch = true`
`258`	`258`	`}`
Original file line number	Diff line number	Diff line change
`@@ -175,7 +175,7 @@ func fiximports(packages ...string) bool {`
`175`	`175`	`matchPrefix bool`
`176`	`176`	`}`
`177`	`177`	`var replace []replaceItem`
`178`		`- for _, pair := range strings.Split(*replaceFlag, ",") {`
	`178`	`+ for pair := range strings.SplitSeq(*replaceFlag, ",") {`
`179`	`179`	`if pair == "" {`
`180`	`180`	`continue`
`181`	`181`	`}`
Original file line number	Diff line number	Diff line change
`@@ -191,7 +191,7 @@ func checkGitOrigin() {`
`191`	`191`	`log.Fatalf("Error running git remote -v: %v", msg)`
`192`	`192`	`}`
`193`	`193`	`matches := 0`
`194`		`- for _, line := range strings.Split(string(remotes), "\n") {`
	`194`	`+ for line := range strings.SplitSeq(string(remotes), "\n") {`
`195`	`195`	`line = strings.TrimSpace(line)`
`196`	`196`	`if !strings.HasPrefix(line, "origin") {`
`197`	`197`	`continue`
Original file line number	Diff line number	Diff line change
`@@ -200,7 +200,7 @@ func printSectionBody(file string, depth int, w *bytes.Buffer, elems []present.E`
`200`	`200`	`lines = lines[1:]`
`201`	`201`	`}`
`202`	`202`	`if elem.Pre {`
`203`		`- for _, line := range strings.Split(strings.TrimRight(elem.Raw, "\n"), "\n") {`
	`203`	`+ for line := range strings.SplitSeq(strings.TrimRight(elem.Raw, "\n"), "\n") {`
`204`	`204`	`if line == "" {`
`205`	`205`	`fmt.Fprintf(w, "\n")`
`206`	`206`	`} else {`
Original file line number	Diff line number	Diff line change
`@@ -590,7 +590,7 @@ func check(t Testing, gopath string, act *checker.Action) {`
`590`	`590`	`}`
`591`	`591`	`filename := sanitize(gopath, filename)`
`592`	`592`	`linenum := 0`
`593`		`- for _, line := range strings.Split(string(data), "\n") {`
	`593`	`+ for line := range strings.SplitSeq(string(data), "\n") {`
`594`	`594`	`linenum++`
`595`	`595`
`596`	`596`	`// Hack: treat a comment of the form "//...// want..."`
Original file line number	Diff line number	Diff line change
`@@ -338,7 +338,7 @@ func TestScript(t *testing.T) {`
`338`	`338`
`339`	`339`	`case "skip":`
`340`	`340`	`config := fmt.Sprintf("GOOS=%s GOARCH=%s", runtime.GOOS, runtime.GOARCH)`
`341`		`- for _, word := range strings.Fields(rest) {`
	`341`	`+ for word := range strings.FieldsSeq(rest) {`
`342`	`342`	`if strings.Contains(config, word) {`
`343`	`343`	`t.Skip(word)`
`344`	`344`	`}`