all: modernize -fix ./...

cache/cache.go

@@ -55,7 +55,7 @@ func Open(dir string) (*Cache, error) {
 	if !info.IsDir() {
 		return nil, &fs.PathError{Op: "open", Path: dir, Err: fmt.Errorf("not a directory")}
 	}
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		name := filepath.Join(dir, fmt.Sprintf("%02x", i))
 		if err := os.MkdirAll(name, 0777); err != nil {
 			return nil, err
@@ -332,7 +332,7 @@ func (c *Cache) Trim() error {
 	// We subtract an additional mtimeInterval
 	// to account for the imprecision of our "last used" mtimes.
 	cutoff := now.Add(-trimLimit - mtimeInterval)
-	for i := 0; i < 256; i++ {
+	for i := range 256 {
 		subdir := filepath.Join(c.dir, fmt.Sprintf("%02x", i))
 		c.trimSubdir(subdir, cutoff)
 	}

cache/cache_test.go

@@ -80,7 +80,7 @@ func TestGrowth(t *testing.T) {
 		n = 10
 	}
 
-	for i := 0; i < n; i++ {
+	for i := range n {
 		if err := c.putIndexEntry(dummyID(i), dummyID(i*99), int64(i)*101, true); err != nil {
 			t.Fatalf("addIndexEntry: %v", err)
 		}
@@ -93,7 +93,7 @@ func TestGrowth(t *testing.T) {
 			t.Errorf("Get(%x) = %x, %d, want %x, %d", id, entry.OutputID, entry.Size, dummyID(i*99), int64(i)*101)
 		}
 	}
-	for i := 0; i < n; i++ {
+	for i := range n {
 		id := ActionID(dummyID(i))
 		entry, err := c.Get(id)
 		if err != nil {

cmd/testscript/main.go

@@ -184,11 +184,11 @@ type runT struct {
 	failed        atomic.Bool
 }
 
-func (r *runT) Skip(is ...interface{}) {
+func (r *runT) Skip(is ...any) {
 	panic(skipRun)
 }
 
-func (r *runT) Fatal(is ...interface{}) {
+func (r *runT) Fatal(is ...any) {
 	r.Log(is...)
 	r.FailNow()
 }
@@ -197,7 +197,7 @@ func (r *runT) Parallel() {
 	// TODO run tests in parallel.
 }
 
-func (r *runT) Log(is ...interface{}) {
+func (r *runT) Log(is ...any) {
 	msg := fmt.Sprint(is...)
 	if r.stdinTempFile != "" {
 		msg = strings.ReplaceAll(msg, r.stdinTempFile, "<stdin>")

cmd/txtar-addmod/addmod.go

@@ -55,7 +55,7 @@ It is acceptable to edit the archive afterward to remove or shorten files.
 
 var tmpdir string
 
-func fatalf(format string, args ...interface{}) {
+func fatalf(format string, args ...any) {
 	os.RemoveAll(tmpdir)
 	log.Fatalf(format, args...)
 }
@@ -150,7 +150,7 @@ func main() {
 			filePrefix = ".gomodproxy/" + modDir + "/"
 		} else {
 			// No comment if we're writing to stdout.
-			a.Comment = []byte(fmt.Sprintf("module %s\n\n", title))
+			a.Comment = fmt.Appendf(nil, "module %s\n\n", title)
 		}
 		a.Files = []txtar.File{
 			{Name: filePrefix + ".mod", Data: mod},

diff/diff.go

@@ -116,10 +116,7 @@ func Diff(oldName string, old []byte, newName string, new []byte) []byte {
 
 		// End chunk with common lines for context.
 		if len(ctext) > 0 {
-			n := end.x - start.x
-			if n > C {
-				n = C
-			}
+			n := min(end.x-start.x, C)
 			for _, s := range x[start.x : start.x+n] {
 				ctext = append(ctext, " "+s)
 				count.x++
@@ -234,7 +231,7 @@ func tgs(x, y []string) []pair {
 	for i := range T {
 		T[i] = n + 1
 	}
-	for i := 0; i < n; i++ {
+	for i := range n {
 		k := sort.Search(n, func(k int) bool {
 			return T[k] >= J[i]
 		})

fmtsort/sort.go

@@ -143,14 +143,14 @@ func compare(aVal, bVal reflect.Value) int {
 			return 0
 		}
 	case reflect.Struct:
-		for i := 0; i < aVal.NumField(); i++ {
+		for i := range aVal.NumField() {
 			if c := compare(aVal.Field(i), bVal.Field(i)); c != 0 {
 				return c
 			}
 		}
 		return 0
 	case reflect.Array:
-		for i := 0; i < aVal.Len(); i++ {
+		for i := range aVal.Len() {
 			if c := compare(aVal.Index(i), bVal.Index(i)); c != 0 {
 				return c
 			}

fmtsort/sort_test.go

@@ -36,12 +36,12 @@ var compareTests = [][]reflect.Value{
 	ct(reflect.TypeOf(chans[0]), chans[0], chans[1], chans[2]),
 	ct(reflect.TypeOf(toy{}), toy{0, 1}, toy{0, 2}, toy{1, -1}, toy{1, 1}),
 	ct(reflect.TypeOf([2]int{}), [2]int{1, 1}, [2]int{1, 2}, [2]int{2, 0}),
-	ct(reflect.TypeOf(interface{}(interface{}(0))), iFace, 1, 2, 3),
+	ct(reflect.TypeOf(any(any(0))), iFace, 1, 2, 3),
 }
 
-var iFace interface{}
+var iFace any
 
-func ct(typ reflect.Type, args ...interface{}) []reflect.Value {
+func ct(typ reflect.Type, args ...any) []reflect.Value {
 	value := make([]reflect.Value, len(args))
 	for i, v := range args {
 		x := reflect.ValueOf(v)
@@ -82,9 +82,9 @@ func TestCompare(t *testing.T) {
 }
 
 type sortTest struct {
-	data            interface{} // Always a map.
-	print           string      // Printed result using our custom printer.
-	printBrokenNaNs string      // Printed result when NaN support is broken (pre Go1.12).
+	data            any    // Always a map.
+	print           string // Printed result using our custom printer.
+	printBrokenNaNs string // Printed result when NaN support is broken (pre Go1.12).
 }
 
 var sortTests = []sortTest{
@@ -132,7 +132,7 @@ var sortTests = []sortTest{
 	},
 }
 
-func sprint(data interface{}) string {
+func sprint(data any) string {
 	om := fmtsort.Sort(reflect.ValueOf(data))
 	if om == nil {
 		return "nil"
@@ -219,7 +219,7 @@ func TestInterface(t *testing.T) {
 	// A map containing multiple concrete types should be sorted by type,
 	// then value. However, the relative ordering of types is unspecified,
 	// so test this by checking the presence of sorted subgroups.
-	m := map[interface{}]string{
+	m := map[any]string{
 		[2]int{1, 0}:             "",
 		[2]int{0, 1}:             "",
 		true:                     "",

goproxytest/allhex.go

@@ -8,7 +8,7 @@ package goproxytest
 
 // allHex reports whether the revision rev is entirely lower-case hexadecimal digits.
 func allHex(rev string) bool {
-	for i := 0; i < len(rev); i++ {
+	for i := range len(rev) {
 		c := rev[i]
 		if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' {
 			continue

goproxytest/proxy.go

@@ -239,7 +239,7 @@ func (srv *Server) handler(w http.ResponseWriter, r *http.Request) {
 			zip []byte
 			err error
 		}
-		c := srv.zipCache.Do(a, func() interface{} {
+		c := srv.zipCache.Do(a, func() any {
 			var buf bytes.Buffer
 			z := zip.NewWriter(&buf)
 			for _, f := range a.Files {
@@ -305,7 +305,7 @@ func (srv *Server) readArchive(path, vers string) *txtar.Archive {
 	name := filepath.Join(srv.dir, prefix+"_"+encVers)
 	txtName := name + ".txt"
 	txtarName := name + ".txtar"
-	a := srv.archiveCache.Do(name, func() interface{} {
+	a := srv.archiveCache.Do(name, func() any {
 		a, err := txtar.ParseFile(txtarName)
 		if os.IsNotExist(err) {
 			// fall back to trying with the .txt extension

imports/read.go

@@ -123,7 +123,7 @@ func (r *importReader) nextByte(skipSpace bool) byte {
 // If the keyword is not present, readKeyword records a syntax error.
 func (r *importReader) readKeyword(kw string) {
 	r.peekByte(true)
-	for i := 0; i < len(kw); i++ {
+	for i := range len(kw) {
 		if r.nextByte(false) != kw[i] {
 			r.syntaxError()
 			return

par/work.go

@@ -14,24 +14,24 @@ import (
 // Work manages a set of work items to be executed in parallel, at most once each.
 // The items in the set must all be valid map keys.
 type Work struct {
-	f       func(interface{}) // function to run for each item
-	running int               // total number of runners
+	f       func(any) // function to run for each item
+	running int       // total number of runners
 
 	mu      sync.Mutex
-	added   map[interface{}]bool // items added to set
-	todo    []interface{}        // items yet to be run
-	wait    sync.Cond            // wait when todo is empty
-	waiting int                  // number of runners waiting for todo
+	added   map[any]bool // items added to set
+	todo    []any        // items yet to be run
+	wait    sync.Cond    // wait when todo is empty
+	waiting int          // number of runners waiting for todo
 }
 
 func (w *Work) init() {
 	if w.added == nil {
-		w.added = make(map[interface{}]bool)
+		w.added = make(map[any]bool)
 	}
 }
 
 // Add adds item to the work set, if it hasn't already been added.
-func (w *Work) Add(item interface{}) {
+func (w *Work) Add(item any) {
 	w.mu.Lock()
 	w.init()
 	if !w.added[item] {
@@ -51,7 +51,7 @@ func (w *Work) Add(item interface{}) {
 // before calling Do (or else Do returns immediately),
 // but it is allowed for f(item) to add new items to the set.
 // Do should only be used once on a given Work.
-func (w *Work) Do(n int, f func(item interface{})) {
+func (w *Work) Do(n int, f func(item any)) {
 	if n < 1 {
 		panic("par.Work.Do: n < 1")
 	}
@@ -63,7 +63,7 @@ func (w *Work) Do(n int, f func(item interface{})) {
 	w.f = f
 	w.wait.L = &w.mu
 
-	for i := 0; i < n-1; i++ {
+	for range n - 1 {
 		go w.runner()
 	}
 	w.runner()
@@ -110,13 +110,13 @@ type Cache struct {
 type cacheEntry struct {
 	done   uint32
 	mu     sync.Mutex
-	result interface{}
+	result any
 }
 
 // Do calls the function f if and only if Do is being called for the first time with this key.
 // No call to Do with a given key returns until the one call to f returns.
 // Do returns the value returned by the one call to f.
-func (c *Cache) Do(key interface{}, f func() interface{}) interface{} {
+func (c *Cache) Do(key any, f func() any) any {
 	entryIface, ok := c.m.Load(key)
 	if !ok {
 		entryIface, _ = c.m.LoadOrStore(key, new(cacheEntry))
@@ -136,7 +136,7 @@ func (c *Cache) Do(key interface{}, f func() interface{}) interface{} {
 // Get returns the cached result associated with key.
 // It returns nil if there is no such result.
 // If the result for key is being computed, Get does not wait for the computation to finish.
-func (c *Cache) Get(key interface{}) interface{} {
+func (c *Cache) Get(key any) any {
 	entryIface, ok := c.m.Load(key)
 	if !ok {
 		return nil

par/work_test.go

@@ -16,7 +16,7 @@ func TestWork(t *testing.T) {
 	const N = 10000
 	n := int32(0)
 	w.Add(N)
-	w.Do(100, func(x interface{}) {
+	w.Do(100, func(x any) {
 		atomic.AddInt32(&n, 1)
 		i := x.(int)
 		if i >= 2 {
@@ -32,15 +32,15 @@ func TestWork(t *testing.T) {
 }
 
 func TestWorkParallel(t *testing.T) {
-	for tries := 0; tries < 10; tries++ {
+	for range 10 {
 		var w Work
 		const N = 100
-		for i := 0; i < N; i++ {
+		for i := range N {
 			w.Add(i)
 		}
 		start := time.Now()
 		var n int32
-		w.Do(N, func(x interface{}) {
+		w.Do(N, func(x any) {
 			time.Sleep(1 * time.Millisecond)
 			atomic.AddInt32(&n, +1)
 		})
@@ -58,19 +58,19 @@ func TestCache(t *testing.T) {
 	var cache Cache
 
 	n := 1
-	v := cache.Do(1, func() interface{} { n++; return n })
+	v := cache.Do(1, func() any { n++; return n })
 	if v != 2 {
 		t.Fatalf("cache.Do(1) did not run f")
 	}
-	v = cache.Do(1, func() interface{} { n++; return n })
+	v = cache.Do(1, func() any { n++; return n })
 	if v != 2 {
 		t.Fatalf("cache.Do(1) ran f again!")
 	}
-	v = cache.Do(2, func() interface{} { n++; return n })
+	v = cache.Do(2, func() any { n++; return n })
 	if v != 3 {
 		t.Fatalf("cache.Do(2) did not run f")
 	}
-	v = cache.Do(1, func() interface{} { n++; return n })
+	v = cache.Do(1, func() any { n++; return n })
 	if v != 2 {
 		t.Fatalf("cache.Do(1) did not returned saved value from original cache.Do(1)")
 	}

testscript/cmd.go

@@ -13,6 +13,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -592,7 +593,7 @@ func (ts *TestScript) waitBackgroundOne(bgName string) {
 	// Remove this process from the list of running background processes.
 	for i := range ts.background {
 		if bg == &ts.background[i] {
-			ts.background = append(ts.background[:i], ts.background[i+1:]...)
+			ts.background = slices.Delete(ts.background, i, i+1)
 			break
 		}
 	}