net: use strings.SplitSeq and bytes.SplitSeq

Replace `for _, s := range {strings, bytes}.Split(v, sep)` with
`for s := range {strings, bytes}.SplitSeq(v, sep)`, to simplify
the code and reduce some memory allocations.

Change-Id: Idead4de1e3928fc75cc5ba8caeff85542f1243d5
GitHub-Last-Rev: 5fb196a073e7583b23b1ebb446d6c067580ed63a
GitHub-Pull-Request: golang/go#71554
Reviewed-on: https://go-review.googlesource.com/c/go/+/646216
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

6 files changed, 6 insertions, 6 deletions

diff --git a/src/net/http/fs.go b/src/net/http/fs.go
index e990f196d6..48ba05a664 100644
--- a/src/net/http/fs.go
+++ b/src/net/http/fs.go
@@ -1014,7 +1014,7 @@ func parseRange(s string, size int64) ([]httpRange, error) {
 	}
 	var ranges []httpRange
 	noOverlap := false
-	for _, ra := range strings.Split(s[len(b):], ",") {
+	for ra := range strings.SplitSeq(s[len(b):], ",") {
 		ra = textproto.TrimString(ra)
 		if ra == "" {
 			continue
diff --git a/src/net/http/httptest/recorder.go b/src/net/http/httptest/recorder.go
index dd51901b0d..17aa70f067 100644
--- a/src/net/http/httptest/recorder.go
+++ b/src/net/http/httptest/recorder.go
@@ -207,7 +207,7 @@ func (rw *ResponseRecorder) Result() *http.Response {
 	if trailers, ok := rw.snapHeader["Trailer"]; ok {
 		res.Trailer = make(http.Header, len(trailers))
 		for _, k := range trailers {
-			for _, k := range strings.Split(k, ",") {
+			for k := range strings.SplitSeq(k, ",") {
 				k = http.CanonicalHeaderKey(textproto.TrimString(k))
 				if !httpguts.ValidTrailerHeader(k) {
 					// Ignore since forbidden by RFC 7230, section 4.1.2.
diff --git a/src/net/http/httputil/reverseproxy.go b/src/net/http/httputil/reverseproxy.go
index d64d2fc3a1..15e9684708 100644
--- a/src/net/http/httputil/reverseproxy.go
+++ b/src/net/http/httputil/reverseproxy.go
@@ -577,7 +577,7 @@ func shouldPanicOnCopyError(req *http.Request) bool {
 func removeHopByHopHeaders(h http.Header) {
 	// RFC 7230, section 6.1: Remove headers listed in the "Connection" header.
 	for _, f := range h["Connection"] {
-		for _, sf := range strings.Split(f, ",") {
+		for sf := range strings.SplitSeq(f, ",") {
 			if sf = textproto.TrimString(sf); sf != "" {
 				h.Del(sf)
 			}
diff --git a/src/net/http/httputil/reverseproxy_test.go b/src/net/http/httputil/reverseproxy_test.go
index 2f9a5eec5c..c618f6f19e 100644
--- a/src/net/http/httputil/reverseproxy_test.go
+++ b/src/net/http/httputil/reverseproxy_test.go
@@ -197,7 +197,7 @@ func TestReverseProxyStripHeadersPresentInConnection(t *testing.T) {
 		c := r.Header["Connection"]
 		var cf []string
 		for _, f := range c {
-			for _, sf := range strings.Split(f, ",") {
+			for sf := range strings.SplitSeq(f, ",") {
 				if sf = strings.TrimSpace(sf); sf != "" {
 					cf = append(cf, sf)
 				}
diff --git a/src/net/http/main_test.go b/src/net/http/main_test.go
index 4c18320717..0c58a94f20 100644
--- a/src/net/http/main_test.go
+++ b/src/net/http/main_test.go
@@ -31,7 +31,7 @@ func TestMain(m *testing.M) {
 func interestingGoroutines() (gs []string) {
 	buf := make([]byte, 2<<20)
 	buf = buf[:runtime.Stack(buf, true)]
-	for _, g := range strings.Split(string(buf), "\n\n") {
+	for g := range strings.SplitSeq(string(buf), "\n\n") {
 		_, stack, _ := strings.Cut(g, "\n")
 		stack = strings.TrimSpace(stack)
 		if stack == "" ||
diff --git a/src/net/http/server.go b/src/net/http/server.go
index 1e8e1437d2..cbdc9dd0e3 100644
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -1590,7 +1590,7 @@ func foreachHeaderElement(v string, fn func(string)) {
 		fn(v)
 		return
 	}
-	for _, f := range strings.Split(v, ",") {
+	for f := range strings.SplitSeq(v, ",") {
 		if f = textproto.TrimString(f); f != "" {
 			fn(f)
 		}