exp/norm: use rune

Nothing terribly interesting here. (!)

Since the public APIs are all in terms of UTF-8,
the changes are all internal only.

R=mpvl, gri, r
CC=golang-dev
https://golang.org/cl/5309042

9 files changed, 94 insertions, 94 deletions

diff --git a/src/pkg/exp/norm/composition.go b/src/pkg/exp/norm/composition.go
index 1d722230d6..7965ffc574 100644
--- a/src/pkg/exp/norm/composition.go
+++ b/src/pkg/exp/norm/composition.go
@@ -126,26 +126,26 @@ func (rb *reorderBuffer) insert(src input, i int, info runeInfo) bool {
 }
 
 // appendRune inserts a rune at the end of the buffer. It is used for Hangul.
-func (rb *reorderBuffer) appendRune(rune uint32) {
+func (rb *reorderBuffer) appendRune(r uint32) {
 	bn := rb.nbyte
-	sz := utf8.EncodeRune(rb.byte[bn:], int(rune))
+	sz := utf8.EncodeRune(rb.byte[bn:], rune(r))
 	rb.nbyte += utf8.UTFMax
 	rb.rune[rb.nrune] = runeInfo{bn, uint8(sz), 0, 0}
 	rb.nrune++
 }
 
 // assignRune sets a rune at position pos. It is used for Hangul and recomposition.
-func (rb *reorderBuffer) assignRune(pos int, rune uint32) {
+func (rb *reorderBuffer) assignRune(pos int, r uint32) {
 	bn := rb.rune[pos].pos
-	sz := utf8.EncodeRune(rb.byte[bn:], int(rune))
+	sz := utf8.EncodeRune(rb.byte[bn:], rune(r))
 	rb.rune[pos] = runeInfo{bn, uint8(sz), 0, 0}
 }
 
 // runeAt returns the rune at position n. It is used for Hangul and recomposition.
 func (rb *reorderBuffer) runeAt(n int) uint32 {
 	inf := rb.rune[n]
-	rune, _ := utf8.DecodeRune(rb.byte[inf.pos : inf.pos+inf.size])
-	return uint32(rune)
+	r, _ := utf8.DecodeRune(rb.byte[inf.pos : inf.pos+inf.size])
+	return uint32(r)
 }
 
 // bytesAt returns the UTF-8 encoding of the rune at position n.
@@ -237,17 +237,17 @@ func isHangulWithoutJamoT(b []byte) bool {
 // decomposeHangul algorithmically decomposes a Hangul rune into
 // its Jamo components.
 // See http://unicode.org/reports/tr15/#Hangul for details on decomposing Hangul.
-func (rb *reorderBuffer) decomposeHangul(rune uint32) bool {
+func (rb *reorderBuffer) decomposeHangul(r uint32) bool {
 	b := rb.rune[:]
 	n := rb.nrune
 	if n+3 > len(b) {
 		return false
 	}
-	rune -= hangulBase
-	x := rune % jamoTCount
-	rune /= jamoTCount
-	rb.appendRune(jamoLBase + rune/jamoVCount)
-	rb.appendRune(jamoVBase + rune%jamoVCount)
+	r -= hangulBase
+	x := r % jamoTCount
+	r /= jamoTCount
+	rb.appendRune(jamoLBase + r/jamoVCount)
+	rb.appendRune(jamoVBase + r%jamoVCount)
 	if x != 0 {
 		rb.appendRune(jamoTBase + x)
 	}
diff --git a/src/pkg/exp/norm/composition_test.go b/src/pkg/exp/norm/composition_test.go
index ce9caaff16..e32380d7af 100644
--- a/src/pkg/exp/norm/composition_test.go
+++ b/src/pkg/exp/norm/composition_test.go
@@ -8,14 +8,14 @@ import "testing"
 
 // TestCase is used for most tests.
 type TestCase struct {
-	in  []int
-	out []int
+	in  []rune
+	out []rune
 }
 
-type insertFunc func(rb *reorderBuffer, rune int) bool
+type insertFunc func(rb *reorderBuffer, r rune) bool
 
-func insert(rb *reorderBuffer, rune int) bool {
-	src := inputString(string(rune))
+func insert(rb *reorderBuffer, r rune) bool {
+	src := inputString(string(r))
 	return rb.insert(src, 0, rb.f.info(src, 0))
 }
 
@@ -39,7 +39,7 @@ func runTests(t *testing.T, name string, fm Form, f insertFunc, tests []TestCase
 			continue
 		}
 		for j, want := range test.out {
-			found := int(rb.runeAt(j))
+			found := rune(rb.runeAt(j))
 			if found != want {
 				t.Errorf("%s:%d: runeAt(%d) = %U; want %U", name, i, j, found, want)
 			}
@@ -57,7 +57,7 @@ func TestFlush(t *testing.T) {
 		t.Errorf("wrote bytes on flush of empty buffer. (len(out) = %d)", len(out))
 	}
 
-	for _, r := range []int("world!") {
+	for _, r := range []rune("world!") {
 		insert(&rb, r)
 	}
 
@@ -76,14 +76,14 @@ func TestFlush(t *testing.T) {
 }
 
 var insertTests = []TestCase{
-	{[]int{'a'}, []int{'a'}},
-	{[]int{0x300}, []int{0x300}},
-	{[]int{0x300, 0x316}, []int{0x316, 0x300}}, // CCC(0x300)==230; CCC(0x316)==220
-	{[]int{0x316, 0x300}, []int{0x316, 0x300}},
-	{[]int{0x41, 0x316, 0x300}, []int{0x41, 0x316, 0x300}},
-	{[]int{0x41, 0x300, 0x316}, []int{0x41, 0x316, 0x300}},
-	{[]int{0x300, 0x316, 0x41}, []int{0x316, 0x300, 0x41}},
-	{[]int{0x41, 0x300, 0x40, 0x316}, []int{0x41, 0x300, 0x40, 0x316}},
+	{[]rune{'a'}, []rune{'a'}},
+	{[]rune{0x300}, []rune{0x300}},
+	{[]rune{0x300, 0x316}, []rune{0x316, 0x300}}, // CCC(0x300)==230; CCC(0x316)==220
+	{[]rune{0x316, 0x300}, []rune{0x316, 0x300}},
+	{[]rune{0x41, 0x316, 0x300}, []rune{0x41, 0x316, 0x300}},
+	{[]rune{0x41, 0x300, 0x316}, []rune{0x41, 0x316, 0x300}},
+	{[]rune{0x300, 0x316, 0x41}, []rune{0x316, 0x300, 0x41}},
+	{[]rune{0x41, 0x300, 0x40, 0x316}, []rune{0x41, 0x300, 0x40, 0x316}},
 }
 
 func TestInsert(t *testing.T) {
@@ -91,18 +91,18 @@ func TestInsert(t *testing.T) {
 }
 
 var decompositionNFDTest = []TestCase{
-	{[]int{0xC0}, []int{0x41, 0x300}},
-	{[]int{0xAC00}, []int{0x1100, 0x1161}},
-	{[]int{0x01C4}, []int{0x01C4}},
-	{[]int{0x320E}, []int{0x320E}},
-	{[]int("음ẻ과"), []int{0x110B, 0x1173, 0x11B7, 0x65, 0x309, 0x1100, 0x116A}},
+	{[]rune{0xC0}, []rune{0x41, 0x300}},
+	{[]rune{0xAC00}, []rune{0x1100, 0x1161}},
+	{[]rune{0x01C4}, []rune{0x01C4}},
+	{[]rune{0x320E}, []rune{0x320E}},
+	{[]rune("음ẻ과"), []rune{0x110B, 0x1173, 0x11B7, 0x65, 0x309, 0x1100, 0x116A}},
 }
 
 var decompositionNFKDTest = []TestCase{
-	{[]int{0xC0}, []int{0x41, 0x300}},
-	{[]int{0xAC00}, []int{0x1100, 0x1161}},
-	{[]int{0x01C4}, []int{0x44, 0x5A, 0x030C}},
-	{[]int{0x320E}, []int{0x28, 0x1100, 0x1161, 0x29}},
+	{[]rune{0xC0}, []rune{0x41, 0x300}},
+	{[]rune{0xAC00}, []rune{0x1100, 0x1161}},
+	{[]rune{0x01C4}, []rune{0x44, 0x5A, 0x030C}},
+	{[]rune{0x320E}, []rune{0x28, 0x1100, 0x1161, 0x29}},
 }
 
 func TestDecomposition(t *testing.T) {
@@ -111,15 +111,15 @@ func TestDecomposition(t *testing.T) {
 }
 
 var compositionTest = []TestCase{
-	{[]int{0x41, 0x300}, []int{0xC0}},
-	{[]int{0x41, 0x316}, []int{0x41, 0x316}},
-	{[]int{0x41, 0x300, 0x35D}, []int{0xC0, 0x35D}},
-	{[]int{0x41, 0x316, 0x300}, []int{0xC0, 0x316}},
+	{[]rune{0x41, 0x300}, []rune{0xC0}},
+	{[]rune{0x41, 0x316}, []rune{0x41, 0x316}},
+	{[]rune{0x41, 0x300, 0x35D}, []rune{0xC0, 0x35D}},
+	{[]rune{0x41, 0x316, 0x300}, []rune{0xC0, 0x316}},
 	// blocking starter
-	{[]int{0x41, 0x316, 0x40, 0x300}, []int{0x41, 0x316, 0x40, 0x300}},
-	{[]int{0x1100, 0x1161}, []int{0xAC00}},
+	{[]rune{0x41, 0x316, 0x40, 0x300}, []rune{0x41, 0x316, 0x40, 0x300}},
+	{[]rune{0x1100, 0x1161}, []rune{0xAC00}},
 	// parenthesized Hangul, alternate between ASCII and Hangul.
-	{[]int{0x28, 0x1100, 0x1161, 0x29}, []int{0x28, 0xAC00, 0x29}},
+	{[]rune{0x28, 0x1100, 0x1161, 0x29}, []rune{0x28, 0xAC00, 0x29}},
 }
 
 func TestComposition(t *testing.T) {
diff --git a/src/pkg/exp/norm/maketables.go b/src/pkg/exp/norm/maketables.go
index 14718c5cd2..626f324a54 100644
--- a/src/pkg/exp/norm/maketables.go
+++ b/src/pkg/exp/norm/maketables.go
@@ -119,7 +119,7 @@ const (
 // This contains only the properties we're interested in.
 type Char struct {
 	name          string
-	codePoint     int   // if zero, this index is not a valid code point.
+	codePoint     rune  // if zero, this index is not a valid code point.
 	ccc           uint8 // canonical combining class
 	excludeInComp bool  // from CompositionExclusions.txt
 	compatDecomp  bool  // it has a compatibility expansion
@@ -160,7 +160,7 @@ const (
 	SMissing
 )
 
-var lastChar int = 0
+var lastChar = rune('\u0000')
 
 func (c Char) isValid() bool {
 	return c.codePoint != 0 && c.state != SMissing
@@ -193,7 +193,7 @@ func (f FormInfo) String() string {
 	return buf.String()
 }
 
-type Decomposition []int
+type Decomposition []rune
 
 func (d Decomposition) String() string {
 	return fmt.Sprintf("%.4X", d)
@@ -220,7 +220,7 @@ func openReader(file string) (input io.ReadCloser) {
 	return
 }
 
-func parseDecomposition(s string, skipfirst bool) (a []int, e os.Error) {
+func parseDecomposition(s string, skipfirst bool) (a []rune, e os.Error) {
 	decomp := strings.Split(s, " ")
 	if len(decomp) > 0 && skipfirst {
 		decomp = decomp[1:]
@@ -230,7 +230,7 @@ func parseDecomposition(s string, skipfirst bool) (a []int, e os.Error) {
 		if err != nil {
 			return a, err
 		}
-		a = append(a, int(point))
+		a = append(a, rune(point))
 	}
 	return a, nil
 }
@@ -260,7 +260,7 @@ func parseCharacter(line string) {
 		state = SLast
 	}
 	firstChar := lastChar + 1
-	lastChar = int(point)
+	lastChar = rune(point)
 	if state != SLast {
 		firstChar = lastChar
 	}
@@ -370,8 +370,8 @@ func loadCompositionExclusions() {
 // hasCompatDecomp returns true if any of the recursive
 // decompositions contains a compatibility expansion.
 // In this case, the character may not occur in NFK*.
-func hasCompatDecomp(rune int) bool {
-	c := &chars[rune]
+func hasCompatDecomp(r rune) bool {
+	c := &chars[r]
 	if c.compatDecomp {
 		return true
 	}
@@ -396,19 +396,19 @@ const (
 	JamoTEnd  = 0x11C3
 )
 
-func isHangul(rune int) bool {
-	return HangulBase <= rune && rune < HangulEnd
+func isHangul(r rune) bool {
+	return HangulBase <= r && r < HangulEnd
 }
 
-func ccc(rune int) uint8 {
-	return chars[rune].ccc
+func ccc(r rune) uint8 {
+	return chars[r].ccc
 }
 
 // Insert a rune in a buffer, ordered by Canonical Combining Class.
-func insertOrdered(b Decomposition, rune int) Decomposition {
+func insertOrdered(b Decomposition, r rune) Decomposition {
 	n := len(b)
 	b = append(b, 0)
-	cc := ccc(rune)
+	cc := ccc(r)
 	if cc > 0 {
 		// Use bubble sort.
 		for ; n > 0; n-- {
@@ -418,18 +418,18 @@ func insertOrdered(b Decomposition, rune int) Decomposition {
 			b[n] = b[n-1]
 		}
 	}
-	b[n] = rune
+	b[n] = r
 	return b
 }
 
 // Recursively decompose.
-func decomposeRecursive(form int, rune int, d Decomposition) Decomposition {
-	if isHangul(rune) {
+func decomposeRecursive(form int, r rune, d Decomposition) Decomposition {
+	if isHangul(r) {
 		return d
 	}
-	dcomp := chars[rune].forms[form].decomp
+	dcomp := chars[r].forms[form].decomp
 	if len(dcomp) == 0 {
-		return insertOrdered(d, rune)
+		return insertOrdered(d, r)
 	}
 	for _, c := range dcomp {
 		d = decomposeRecursive(form, c, d)
@@ -475,8 +475,8 @@ func completeCharFields(form int) {
 			f.isOneWay = f.isOneWay || hasCompatDecomp(c.codePoint)
 		}
 
-		for _, rune := range f.decomp {
-			chars[rune].forms[form].inDecomp = true
+		for _, r := range f.decomp {
+			chars[r].forms[form].inDecomp = true
 		}
 	}
 
@@ -505,7 +505,7 @@ func completeCharFields(form int) {
 		switch {
 		case len(f.decomp) > 0:
 			f.quickCheck[MDecomposed] = QCNo
-		case isHangul(i):
+		case isHangul(rune(i)):
 			f.quickCheck[MDecomposed] = QCNo
 		default:
 			f.quickCheck[MDecomposed] = QCYes
@@ -588,7 +588,7 @@ func printCharInfoTables() int {
 	for i, char := range chars {
 		v := makeCharInfo(char)
 		if v != 0 {
-			t.insert(i, v)
+			t.insert(rune(i), v)
 		}
 	}
 	return t.printTables("charInfo")
@@ -606,7 +606,7 @@ func printDecompositionTables() int {
 	for _, c := range chars {
 		for f := 0; f < 2; f++ {
 			d := c.forms[f].expandedDecomp
-			s := string([]int(d))
+			s := string([]rune(d))
 			if _, ok := positionMap[s]; !ok {
 				p := decompositions.Len()
 				decompositions.WriteByte(uint8(len(s)))
@@ -624,7 +624,7 @@ func printDecompositionTables() int {
 	for i, c := range chars {
 		d := c.forms[FCanonical].expandedDecomp
 		if len(d) != 0 {
-			nfcT.insert(i, positionMap[string([]int(d))])
+			nfcT.insert(rune(i), positionMap[string([]rune(d))])
 			if ccc(c.codePoint) != ccc(d[0]) {
 				// We assume the lead ccc of a decomposition is !=0 in this case.
 				if ccc(d[0]) == 0 {
@@ -634,7 +634,7 @@ func printDecompositionTables() int {
 		}
 		d = c.forms[FCompatibility].expandedDecomp
 		if len(d) != 0 {
-			nfkcT.insert(i, positionMap[string([]int(d))])
+			nfkcT.insert(rune(i), positionMap[string([]rune(d))])
 			if ccc(c.codePoint) != ccc(d[0]) {
 				// We assume the lead ccc of a decomposition is !=0 in this case.
 				if ccc(d[0]) == 0 {
@@ -752,7 +752,7 @@ func verifyComputed() {
 	for i, c := range chars {
 		for _, f := range c.forms {
 			isNo := (f.quickCheck[MDecomposed] == QCNo)
-			if (len(f.decomp) > 0) != isNo && !isHangul(i) {
+			if (len(f.decomp) > 0) != isNo && !isHangul(rune(i)) {
 				log.Fatalf("%U: NF*D must be no if rune decomposes", i)
 			}
 
diff --git a/src/pkg/exp/norm/maketesttables.go b/src/pkg/exp/norm/maketesttables.go
index fdcc114be2..20eb889dde 100644
--- a/src/pkg/exp/norm/maketesttables.go
+++ b/src/pkg/exp/norm/maketesttables.go
@@ -16,7 +16,7 @@ func main() {
 
 // We take the smallest, largest and an arbitrary value for each 
 // of the UTF-8 sequence lengths.
-var testRunes = []int{
+var testRunes = []rune{
 	0x01, 0x0C, 0x7F, // 1-byte sequences
 	0x80, 0x100, 0x7FF, // 2-byte sequences
 	0x800, 0x999, 0xFFFF, // 3-byte sequences
diff --git a/src/pkg/exp/norm/normalize_test.go b/src/pkg/exp/norm/normalize_test.go
index e374edf0ab..6bd5292d3f 100644
--- a/src/pkg/exp/norm/normalize_test.go
+++ b/src/pkg/exp/norm/normalize_test.go
@@ -28,13 +28,13 @@ func runPosTests(t *testing.T, name string, f Form, fn positionFunc, tests []Pos
 		if pos != test.pos {
 			t.Errorf("%s:%d: position is %d; want %d", name, i, pos, test.pos)
 		}
-		runes := []int(test.buffer)
+		runes := []rune(test.buffer)
 		if rb.nrune != len(runes) {
 			t.Errorf("%s:%d: reorder buffer lenght is %d; want %d", name, i, rb.nrune, len(runes))
 			continue
 		}
 		for j, want := range runes {
-			found := int(rb.runeAt(j))
+			found := rune(rb.runeAt(j))
 			if found != want {
 				t.Errorf("%s:%d: rune at %d is %U; want %U", name, i, j, found, want)
 			}
@@ -385,8 +385,8 @@ func runAppendTests(t *testing.T, name string, f Form, fn appendFunc, tests []Ap
 		}
 		if outs != test.out {
 			// Find first rune that differs and show context.
-			ir := []int(outs)
-			ig := []int(test.out)
+			ir := []rune(outs)
+			ig := []rune(test.out)
 			for j := 0; j < len(ir) && j < len(ig); j++ {
 				if ir[j] == ig[j] {
 					continue
diff --git a/src/pkg/exp/norm/normregtest.go b/src/pkg/exp/norm/normregtest.go
index cbd73ffa75..cf3b34023b 100644
--- a/src/pkg/exp/norm/normregtest.go
+++ b/src/pkg/exp/norm/normregtest.go
@@ -103,7 +103,7 @@ type Test struct {
 	name   string
 	partnr int
 	number int
-	rune   int                 // used for character by character test
+	r      rune                // used for character by character test
 	cols   [cMaxColumns]string // Each has 5 entries, see below.
 }
 
@@ -174,12 +174,12 @@ func loadTestData() {
 				if err != nil {
 					logger.Fatal(err)
 				}
-				if test.rune == 0 {
+				if test.r == 0 {
 					// save for CharacterByCharacterTests
-					test.rune = int(r)
+					test.r = int(r)
 				}
 				var buf [utf8.UTFMax]byte
-				sz := utf8.EncodeRune(buf[:], int(r))
+				sz := utf8.EncodeRune(buf[:], rune(r))
 				test.cols[j-1] += string(buf[:sz])
 			}
 		}
@@ -198,7 +198,7 @@ func cmpResult(t *Test, name string, f norm.Form, gold, test, result string) {
 		if errorCount > 20 {
 			return
 		}
-		st, sr, sg := []int(test), []int(result), []int(gold)
+		st, sr, sg := []rune(test), []rune(result), []rune(gold)
 		logger.Printf("%s:%s: %s(%X)=%X; want:%X: %s",
 			t.Name(), name, fstr[f], st, sr, sg, t.name)
 	}
@@ -210,7 +210,7 @@ func cmpIsNormal(t *Test, name string, f norm.Form, test string, result, want bo
 		if errorCount > 20 {
 			return
 		}
-		logger.Printf("%s:%s: %s(%X)=%v; want: %v", t.Name(), name, fstr[f], []int(test), result, want)
+		logger.Printf("%s:%s: %s(%X)=%v; want: %v", t.Name(), name, fstr[f], []rune(test), result, want)
 	}
 }
 
@@ -243,13 +243,13 @@ func CharacterByCharacterTests() {
 	tests := part[1].tests
 	last := 0
 	for i := 0; i <= len(tests); i++ { // last one is special case
-		var rune int
+		var r int
 		if i == len(tests) {
-			rune = 0x2FA1E // Don't have to go to 0x10FFFF
+			r = 0x2FA1E // Don't have to go to 0x10FFFF
 		} else {
-			rune = tests[i].rune
+			r = tests[i].r
 		}
-		for last++; last < rune; last++ {
+		for last++; last < r; last++ {
 			// Check all characters that were not explicitly listed in the test.
 			t := &Test{partnr: 1, number: -1}
 			char := string(last)
diff --git a/src/pkg/exp/norm/trie_test.go b/src/pkg/exp/norm/trie_test.go
index 5649fb7eea..bbd5c03e7b 100644
--- a/src/pkg/exp/norm/trie_test.go
+++ b/src/pkg/exp/norm/trie_test.go
@@ -73,15 +73,15 @@ var tests = []trietest{
 	{1, []byte{t6, tx, tx, tx, tx, tx}},
 }
 
-func mkUtf8(rune int) ([]byte, int) {
+func mkUTF8(r rune) ([]byte, int) {
 	var b [utf8.UTFMax]byte
-	sz := utf8.EncodeRune(b[:], rune)
+	sz := utf8.EncodeRune(b[:], r)
 	return b[:sz], sz
 }
 
 func TestLookup(t *testing.T) {
 	for i, tt := range testRunes {
-		b, szg := mkUtf8(tt)
+		b, szg := mkUTF8(tt)
 		v, szt := testdata.lookup(b)
 		if int(v) != i {
 			t.Errorf("lookup(%U): found value %#x, expected %#x", tt, v, i)
@@ -103,7 +103,7 @@ func TestLookup(t *testing.T) {
 
 func TestLookupUnsafe(t *testing.T) {
 	for i, tt := range testRunes {
-		b, _ := mkUtf8(tt)
+		b, _ := mkUTF8(tt)
 		v := testdata.lookupUnsafe(b)
 		if int(v) != i {
 			t.Errorf("lookupUnsafe(%U): found value %#x, expected %#x", i, v, i)
@@ -113,7 +113,7 @@ func TestLookupUnsafe(t *testing.T) {
 
 func TestLookupString(t *testing.T) {
 	for i, tt := range testRunes {
-		b, szg := mkUtf8(tt)
+		b, szg := mkUTF8(tt)
 		v, szt := testdata.lookupString(string(b))
 		if int(v) != i {
 			t.Errorf("lookup(%U): found value %#x, expected %#x", i, v, i)
@@ -135,7 +135,7 @@ func TestLookupString(t *testing.T) {
 
 func TestLookupStringUnsafe(t *testing.T) {
 	for i, tt := range testRunes {
-		b, _ := mkUtf8(tt)
+		b, _ := mkUTF8(tt)
 		v := testdata.lookupStringUnsafe(string(b))
 		if int(v) != i {
 			t.Errorf("lookupUnsafe(%U): found value %#x, expected %#x", i, v, i)
diff --git a/src/pkg/exp/norm/triedata_test.go b/src/pkg/exp/norm/triedata_test.go
index e8898e5d42..7f6276096c 100644
--- a/src/pkg/exp/norm/triedata_test.go
+++ b/src/pkg/exp/norm/triedata_test.go
@@ -4,7 +4,7 @@
 
 package norm
 
-var testRunes = []int{1, 12, 127, 128, 256, 2047, 2048, 2457, 65535, 65536, 65793, 1114111, 512, 513, 514, 528, 533}
+var testRunes = []rune{1, 12, 127, 128, 256, 2047, 2048, 2457, 65535, 65536, 65793, 1114111, 512, 513, 514, 528, 533}
 
 // testdataValues: 192 entries, 384 bytes
 // Block 2 is the null block.
diff --git a/src/pkg/exp/norm/triegen.go b/src/pkg/exp/norm/triegen.go
index 515e1c7860..56cba32196 100644
--- a/src/pkg/exp/norm/triegen.go
+++ b/src/pkg/exp/norm/triegen.go
@@ -94,9 +94,9 @@ func (n trieNode) countSparseEntries() int {
 	return count
 }
 
-func (n *trieNode) insert(rune int, value uint16) {
+func (n *trieNode) insert(r rune, value uint16) {
 	var p [utf8.UTFMax]byte
-	sz := utf8.EncodeRune(p[:], rune)
+	sz := utf8.EncodeRune(p[:], r)
 
 	for i := 0; i < sz; i++ {
 		if n.leaf {