throughout: simplify two-variable ranges with unused second variable

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/3529041

src/cmd/godoc/godoc.go

@@ -1182,7 +1182,7 @@ func (h *httpHandler) getPageInfo(abspath, relpath, pkgname string, mode PageInf
 		// (excluding the selected package, if any).
 		plist = make([]string, len(pkgs))
 		i := 0
-		for name, _ := range pkgs {
+		for name := range pkgs {
 			if pkg == nil || name != pkg.Name {
 				plist[i] = name
 				i++

src/pkg/container/vector/numbers_test.go

@@ -20,7 +20,7 @@ func s(n uint64) string {
 	lens := len(str)
 	a := make([]string, (lens+2)/3)
 	start := lens
-	for i, _ := range a {
+	for i := range a {
 		start -= 3
 		if start < 0 {
 			start = 0

src/pkg/exp/draw/draw.go

@@ -268,7 +268,7 @@ func drawFillSrc(dst *image.RGBA, r image.Rectangle, src *image.ColorImage) {
 	dbase := dy0 * dst.Stride
 	i0, i1 := dbase+dx0, dbase+dx1
 	firstRow := dst.Pix[i0:i1]
-	for i, _ := range firstRow {
+	for i := range firstRow {
 		firstRow[i] = color
 	}
 	for y := dy0 + 1; y < dy1; y++ {

src/pkg/go/parser/parser_test.go

@@ -104,7 +104,7 @@ func TestParse4(t *testing.T) {
 		t.Errorf(`package "parser" not found`)
 		return
 	}
-	for filename, _ := range pkg.Files {
+	for filename := range pkg.Files {
 		if !nameFilter(filename) {
 			t.Errorf("unexpected package file: %s", filename)
 		}

src/pkg/http/transfer.go

@@ -108,7 +108,7 @@ func (t *transferWriter) WriteHeader(w io.Writer) (err os.Error) {
 		// writing long headers, using HTTP line splitting
 		io.WriteString(w, "Trailer: ")
 		needComma := false
-		for k, _ := range t.Trailer {
+		for k := range t.Trailer {
 			k = CanonicalHeaderKey(k)
 			switch k {
 			case "Transfer-Encoding", "Trailer", "Content-Length":

src/pkg/index/suffixarray/suffixarray.go

@@ -40,7 +40,7 @@ type Index struct {
 //
 func New(data []byte) *Index {
 	sa := make([]int, len(data))
-	for i, _ := range sa {
+	for i := range sa {
 		sa[i] = i
 	}
 	x := &Index{data, sa}

src/pkg/reflect/type.go

@@ -550,7 +550,7 @@ func (t *StructType) fieldByNameFunc(match func(string) bool, mark map[*StructTy
 	var fi int // field index
 	n := 0     // number of matching fields at depth fd
 L:
-	for i, _ := range t.fields {
+	for i := range t.fields {
 		f := t.Field(i)
 		d := inf
 		switch {

src/pkg/unicode/maketables.go

@@ -326,7 +326,7 @@ func printCategories() {
 	if *tablelist == "all" {
 		fmt.Println("// Categories is the set of Unicode data tables.")
 		fmt.Println("var Categories = map[string] []Range {")
-		for k, _ := range category {
+		for k := range category {
 			fmt.Printf("\t%q: %s,\n", k, k)
 		}
 		fmt.Print("}\n\n")
@@ -594,7 +594,7 @@ func printScriptOrProperty(doProps bool) {
 			fmt.Println("// Scripts is the set of Unicode script tables.")
 			fmt.Println("var Scripts = map[string] []Range {")
 		}
-		for k, _ := range table {
+		for k := range table {
 			fmt.Printf("\t%q: %s,\n", k, k)
 		}
 		fmt.Print("}\n\n")

test/blank.go

@@ -77,7 +77,7 @@ func main() {
 	if out != "123" {panic(out)}
 
 	sum := 0
-	for s, _ := range ints {
+	for s := range ints {
 		sum += s
 	}
 	if sum != 3 {panic(sum)}