Modernize Go code

tools/cli/wcswidth_kitten.go

@@ -125,7 +125,7 @@ func run_tests(tests []*test_struct) (err error) {
 			case 'c':
 				lp.Quit(0)
 			case 'R':
-				if idx := bytes.IndexByte(data, ';'); idx > -1 {
+				if found := bytes.Contains(data, []byte{';'}); found {
 					if cpos, err := cpos_from_report(utils.UnsafeBytesToString(data[:len(data)-1])); err != nil {
 						return err
 					} else {

tools/cmd/mouse_demo/main.go

@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"encoding/base64"
 	"fmt"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -261,7 +262,7 @@ func Run(args []string) (rc int, err error) {
 		meta, payload, _ := strings.Cut(rest, ";")
 		// Parse metadata key=value pairs separated by ':'
 		meta_map := make(map[string]string)
-		for _, kv := range strings.Split(meta, ":") {
+		for kv := range strings.SplitSeq(meta, ":") {
 			k, v, _ := strings.Cut(kv, "=")
 			if k != "" {
 				meta_map[k] = v
@@ -300,19 +301,15 @@ func Run(args []string) (rc int, err error) {
 			mimes := strings.Fields(payload)
 			dnd.drop_mimes = mimes
 			// Request data for text/plain first, then text/uri-list
-			for _, m := range mimes {
-				if m == "text/plain" {
-					dnd.collecting = "text/plain"
-					lp.QueueWriteString(dnd_request_data("text/plain"))
-					return nil
-				}
+			if slices.Contains(mimes, "text/plain") {
+				dnd.collecting = "text/plain"
+				lp.QueueWriteString(dnd_request_data("text/plain"))
+				return nil
 			}
-			for _, m := range mimes {
-				if m == "text/uri-list" {
-					dnd.collecting = "text/uri-list"
-					lp.QueueWriteString(dnd_request_data("text/uri-list"))
-					return nil
-				}
+			if slices.Contains(mimes, "text/uri-list") {
+				dnd.collecting = "text/uri-list"
+				lp.QueueWriteString(dnd_request_data("text/uri-list"))
+				return nil
 			}
 			// Nothing to collect, signal done
 			lp.QueueWriteString(dnd_finish())
@@ -325,25 +322,23 @@ func Run(args []string) (rc int, err error) {
 				if dnd.collecting == "text/plain" {
 					text := dnd.collect_buf.String()
 					// Get first line
-					if idx := strings.IndexByte(text, '\n'); idx >= 0 {
-						dnd.plain_text = text[:idx]
+					if before, _, ok := strings.Cut(text, "\n"); ok {
+						dnd.plain_text = before
 					} else {
 						dnd.plain_text = text
 					}
 					dnd.collect_buf.Reset()
 					// Now request text/uri-list if available
-					for _, m := range dnd.drop_mimes {
-						if m == "text/uri-list" {
-							dnd.collecting = "text/uri-list"
-							lp.QueueWriteString(dnd_request_data("text/uri-list"))
-							return nil
-						}
+					if slices.Contains(dnd.drop_mimes, "text/uri-list") {
+						dnd.collecting = "text/uri-list"
+						lp.QueueWriteString(dnd_request_data("text/uri-list"))
+						return nil
 					}
 				} else if dnd.collecting == "text/uri-list" {
 					text := dnd.collect_buf.String()
 					dnd.collect_buf.Reset()
 					// Parse URI list: lines starting with # are comments
-					for _, line := range strings.Split(text, "\n") {
+					for line := range strings.SplitSeq(text, "\n") {
 						line = strings.TrimRight(line, "\r")
 						if line != "" && !strings.HasPrefix(line, "#") {
 							dnd.uri_list = append(dnd.uri_list, line)

tools/rsync/algorithm.go

@@ -646,10 +646,3 @@ func find_hash(hh []BlockHash, hv uint64) (uint64, bool) {
 	}
 	return 0, false
 }
-
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}

tools/tty/tty_bsd.go

@@ -1,6 +1,5 @@
 // License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
 //go:build darwin || freebsd || openbsd || netbsd || dragonfly
-// +build darwin freebsd openbsd netbsd dragonfly
 
 package tty
 

tools/tui/readline/history.go

@@ -309,8 +309,8 @@ func (self *Readline) history_search_highlighter(text string, x, y int) string {
 	lines := utils.Splitlines(text)
 	for _, tok := range self.history_search.tokens {
 		for i, line := range lines {
-			if idx := strings.Index(line, tok); idx > -1 {
-				lines[i] = line[:idx] + self.fmt_ctx.Green(tok) + line[idx+len(tok):]
+			if before, after, ok := strings.Cut(line, tok); ok {
+				lines[i] = before + self.fmt_ctx.Green(tok) + after
 				break
 			}
 		}

tools/utils/strings.go

@@ -69,11 +69,11 @@ func ScanFuncForSeparator(sep string) StringScannerScanFunc {
 
 	}
 	return func(data string) (remaining_data, token string) {
-		idx := strings.Index(data, sep)
-		if idx < 0 {
+		before, after, ok := strings.Cut(data, sep)
+		if !ok {
 			return "", data
 		}
-		return data[idx+len(sep):], data[:idx]
+		return after, before
 	}
 }
 

tools/utils/style/colorspaces_bench_test.go

@@ -9,50 +9,50 @@ import (
 // Benchmark color parsing functions to demonstrate performance
 
 func BenchmarkParseOklch(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, _ = parseOklch("0.5 0.1 180")
 	}
 }
 
 func BenchmarkParseLab(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, _ = parseLab("50 0 0")
 	}
 }
 
 func BenchmarkParseColorHex(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, _ = ParseColor("#ff0000")
 	}
 }
 
 func BenchmarkParseColorOklch(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, _ = ParseColor("oklch(0.5 0.1 180)")
 	}
 }
 
 func BenchmarkParseColorLab(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, _ = ParseColor("lab(50 0 0)")
 	}
 }
 
 func BenchmarkParseColorWithComment(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_, _ = ParseColor("oklch(0.5 0.1 180) # vibrant color")
 	}
 }
 
 // Benchmark the gamut mapping algorithm specifically
 func BenchmarkOklchToSrgbGamutMap(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		oklchToSrgbGamutMap(0.7, 0.4, 25) // Very saturated color requiring gamut mapping
 	}
 }
 
 func BenchmarkOklchToSrgbGamutMapInGamut(b *testing.B) {
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		oklchToSrgbGamutMap(0.5, 0.05, 180) // Already in gamut
 	}
 }
@@ -71,8 +71,7 @@ func BenchmarkParseManyColors(b *testing.B) {
 		"green",
 	}
 
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		for _, color := range colors {
 			_, _ = ParseColor(color)
 		}

tools/wcswidth/char-props-data.go

@@ -388,10 +388,10 @@ var charprops_t3 = [106]CharProps{
 
 // Array accessor function that avoids bounds checking
 func charprops_for(x uint32) CharProps {
-	t1 := uintptr(*(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&charprops_t1[0])) + uintptr(x>>charprops_shift)*1)))
+	t1 := uintptr(*(*uint8)(unsafe.Add(unsafe.Pointer(&charprops_t1[0]), uintptr(x>>charprops_shift)*1)))
 	t1_shifted := (t1 << charprops_shift) + (uintptr(x) & charprops_mask)
-	t2 := uintptr(*(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&charprops_t2[0])) + t1_shifted*1)))
-	return *(*CharProps)(unsafe.Pointer(uintptr(unsafe.Pointer(&charprops_t3[0])) + t2*4))
+	t2 := uintptr(*(*uint8)(unsafe.Add(unsafe.Pointer(&charprops_t2[0]), t1_shifted*1)))
+	return *(*CharProps)(unsafe.Add(unsafe.Pointer(&charprops_t3[0]), t2*4))
 }
 
 const graphemesegmentationresult_mask = 15
@@ -3285,9 +3285,9 @@ var graphemesegmentationresult_t2 = [2880]GraphemeSegmentationResult{
 
 // Array accessor function that avoids bounds checking
 func graphemesegmentationresult_for(x uint16) GraphemeSegmentationResult {
-	t1 := uintptr(*(*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(&graphemesegmentationresult_t1[0])) + uintptr(x>>graphemesegmentationresult_shift)*1)))
+	t1 := uintptr(*(*uint8)(unsafe.Add(unsafe.Pointer(&graphemesegmentationresult_t1[0]), uintptr(x>>graphemesegmentationresult_shift)*1)))
 	t1_shifted := (t1 << graphemesegmentationresult_shift) + (uintptr(x) & graphemesegmentationresult_mask)
-	return *(*GraphemeSegmentationResult)(unsafe.Pointer(uintptr(unsafe.Pointer(&graphemesegmentationresult_t2[0])) + t1_shifted*2))
+	return *(*GraphemeSegmentationResult)(unsafe.Add(unsafe.Pointer(&graphemesegmentationresult_t2[0]), t1_shifted*2))
 }
 
 func grapheme_segmentation_key(r GraphemeSegmentationResult, ch CharProps) uint16 {