exp/norm: introduced input interface to implement string versions

of methods.

R=r, mpvl
CC=golang-dev
https://golang.org/cl/5166045

src/pkg/exp/norm/Makefile

@@ -7,6 +7,7 @@ include ../../../Make.inc
 TARG=exp/norm
 GOFILES=\
 	composition.go\
+	input.go\
 	forminfo.go\
 	normalize.go\
 	readwriter.go\

src/pkg/exp/norm/composition.go

@@ -27,6 +27,26 @@ type reorderBuffer struct {
 	nrune int                     // Number of runeInfos.
 	nbyte uint8                   // Number or bytes.
 	f     formInfo
+
+	src       input
+	nsrc      int
+	srcBytes  inputBytes
+	srcString inputString
+	tmpBytes  inputBytes
+}
+
+func (rb *reorderBuffer) init(f Form, src []byte) {
+	rb.f = *formTable[f]
+	rb.srcBytes = inputBytes(src)
+	rb.src = &rb.srcBytes
+	rb.nsrc = len(src)
+}
+
+func (rb *reorderBuffer) initString(f Form, src string) {
+	rb.f = *formTable[f]
+	rb.srcString = inputString(src)
+	rb.src = &rb.srcString
+	rb.nsrc = len(src)
 }
 
 // reset discards all characters from the buffer.
@@ -75,45 +95,17 @@ func (rb *reorderBuffer) insertOrdered(info runeInfo) bool {
 
 // insert inserts the given rune in the buffer ordered by CCC.
 // It returns true if the buffer was large enough to hold the decomposed rune.
-func (rb *reorderBuffer) insert(src []byte, info runeInfo) bool {
-	if info.size == 3 && isHangul(src) {
-		rune, _ := utf8.DecodeRune(src)
-		return rb.decomposeHangul(uint32(rune))
-	}
-	if info.flags.hasDecomposition() {
-		dcomp := rb.f.decompose(src)
-		for i := 0; i < len(dcomp); {
-			info = rb.f.info(dcomp[i:])
-			pos := rb.nbyte
-			if !rb.insertOrdered(info) {
-				return false
-			}
-			end := i + int(info.size)
-			copy(rb.byte[pos:], dcomp[i:end])
-			i = end
+func (rb *reorderBuffer) insert(src input, i int, info runeInfo) bool {
+	if info.size == 3 {
+		if rune := src.hangul(i); rune != 0 {
+			return rb.decomposeHangul(uint32(rune))
 		}
-	} else {
-		// insertOrder changes nbyte
-		pos := rb.nbyte
-		if !rb.insertOrdered(info) {
-			return false
-		}
-		copy(rb.byte[pos:], src[:info.size])
-	}
-	return true
-}
-
-// insertString inserts the given rune in the buffer ordered by CCC.
-// It returns true if the buffer was large enough to hold the decomposed rune.
-func (rb *reorderBuffer) insertString(src string, info runeInfo) bool {
-	if info.size == 3 && isHangulString(src) {
-		rune, _ := utf8.DecodeRuneInString(src)
-		return rb.decomposeHangul(uint32(rune))
 	}
 	if info.flags.hasDecomposition() {
-		dcomp := rb.f.decomposeString(src)
+		dcomp := rb.f.decompose(src, i)
+		rb.tmpBytes = inputBytes(dcomp)
 		for i := 0; i < len(dcomp); {
-			info = rb.f.info(dcomp[i:])
+			info = rb.f.info(&rb.tmpBytes, i)
 			pos := rb.nbyte
 			if !rb.insertOrdered(info) {
 				return false
@@ -128,7 +120,7 @@ func (rb *reorderBuffer) insertString(src string, info runeInfo) bool {
 		if !rb.insertOrdered(info) {
 			return false
 		}
-		copy(rb.byte[pos:], src[:info.size])
+		src.copySlice(rb.byte[pos:], i, i+int(info.size))
 	}
 	return true
 }

src/pkg/exp/norm/composition_test.go

@@ -15,21 +15,19 @@ type TestCase struct {
 type insertFunc func(rb *reorderBuffer, rune int) bool
 
 func insert(rb *reorderBuffer, rune int) bool {
-	b := []byte(string(rune))
-	return rb.insert(b, rb.f.info(b))
+	src := inputString(string(rune))
+	return rb.insert(src, 0, rb.f.info(src, 0))
 }
 
-func insertString(rb *reorderBuffer, rune int) bool {
-	s := string(rune)
-	return rb.insertString(s, rb.f.infoString(s))
-}
-
-func runTests(t *testing.T, name string, rb *reorderBuffer, f insertFunc, tests []TestCase) {
+func runTests(t *testing.T, name string, fm Form, f insertFunc, tests []TestCase) {
+	rb := reorderBuffer{}
+	rb.init(fm, nil)
 	for i, test := range tests {
 		rb.reset()
 		for j, rune := range test.in {
 			b := []byte(string(rune))
-			if !rb.insert(b, rb.f.info(b)) {
+			src := inputBytes(b)
+			if !rb.insert(src, 0, rb.f.info(src, 0)) {
 				t.Errorf("%s:%d: insert failed for rune %d", name, i, j)
 			}
 		}
@@ -50,7 +48,8 @@ func runTests(t *testing.T, name string, rb *reorderBuffer, f insertFunc, tests
 }
 
 func TestFlush(t *testing.T) {
-	rb := &reorderBuffer{f: *formTable[NFC]}
+	rb := reorderBuffer{}
+	rb.init(NFC, nil)
 	out := make([]byte, 0)
 
 	out = rb.flush(out)
@@ -59,7 +58,7 @@ func TestFlush(t *testing.T) {
 	}
 
 	for _, r := range []int("world!") {
-		insert(rb, r)
+		insert(&rb, r)
 	}
 
 	out = []byte("Hello ")
@@ -88,13 +87,7 @@ var insertTests = []TestCase{
 }
 
 func TestInsert(t *testing.T) {
-	rb := &reorderBuffer{f: *formTable[NFD]}
-	runTests(t, "TestInsert", rb, insert, insertTests)
-}
-
-func TestInsertString(t *testing.T) {
-	rb := &reorderBuffer{f: *formTable[NFD]}
-	runTests(t, "TestInsertString", rb, insertString, insertTests)
+	runTests(t, "TestInsert", NFD, insert, insertTests)
 }
 
 var decompositionNFDTest = []TestCase{
@@ -113,11 +106,8 @@ var decompositionNFKDTest = []TestCase{
 }
 
 func TestDecomposition(t *testing.T) {
-	rb := &reorderBuffer{}
-	rb.f = *formTable[NFD]
-	runTests(t, "TestDecompositionNFD", rb, insert, decompositionNFDTest)
-	rb.f = *formTable[NFKD]
-	runTests(t, "TestDecompositionNFKD", rb, insert, decompositionNFKDTest)
+	runTests(t, "TestDecompositionNFD", NFD, insert, decompositionNFDTest)
+	runTests(t, "TestDecompositionNFKD", NFKD, insert, decompositionNFKDTest)
 }
 
 var compositionTest = []TestCase{
@@ -133,6 +123,5 @@ var compositionTest = []TestCase{
 }
 
 func TestComposition(t *testing.T) {
-	rb := &reorderBuffer{f: *formTable[NFC]}
-	runTests(t, "TestComposition", rb, insert, compositionTest)
+	runTests(t, "TestComposition", NFC, insert, compositionTest)
 }

src/pkg/exp/norm/forminfo.go

@@ -15,10 +15,8 @@ type runeInfo struct {
 
 // functions dispatchable per form
 type boundaryFunc func(f *formInfo, info runeInfo) bool
-type lookupFunc func(b []byte) runeInfo
-type lookupFuncString func(s string) runeInfo
-type decompFunc func(b []byte) []byte
-type decompFuncString func(s string) []byte
+type lookupFunc func(b input, i int) runeInfo
+type decompFunc func(b input, i int) []byte
 
 // formInfo holds Form-specific functions and tables.
 type formInfo struct {
@@ -26,12 +24,10 @@ type formInfo struct {
 
 	composing, compatibility bool // form type
 
-	decompose       decompFunc
-	decomposeString decompFuncString
-	info            lookupFunc
-	infoString      lookupFuncString
-	boundaryBefore  boundaryFunc
-	boundaryAfter   boundaryFunc
+	decompose      decompFunc
+	info           lookupFunc
+	boundaryBefore boundaryFunc
+	boundaryAfter  boundaryFunc
 }
 
 var formTable []*formInfo
@@ -46,14 +42,10 @@ func init() {
 		if Form(i) == NFKD || Form(i) == NFKC {
 			f.compatibility = true
 			f.decompose = decomposeNFKC
-			f.decomposeString = decomposeStringNFKC
 			f.info = lookupInfoNFKC
-			f.infoString = lookupInfoStringNFKC
 		} else {
 			f.decompose = decomposeNFC
-			f.decomposeString = decomposeStringNFC
 			f.info = lookupInfoNFC
-			f.infoString = lookupInfoStringNFC
 		}
 		if Form(i) == NFC || Form(i) == NFKC {
 			f.composing = true
@@ -123,29 +115,15 @@ func (r runeInfo) isInert() bool {
 // array of UTF-8 decomposition sequences. The first byte is the number
 // of bytes in the decomposition (excluding this length byte). The actual
 // sequence starts at the offset+1.
-func decomposeNFC(b []byte) []byte {
-	p := nfcDecompTrie.lookupUnsafe(b)
+func decomposeNFC(s input, i int) []byte {
+	p := s.decomposeNFC(i)
 	n := decomps[p]
 	p++
 	return decomps[p : p+uint16(n)]
 }
 
-func decomposeNFKC(b []byte) []byte {
-	p := nfkcDecompTrie.lookupUnsafe(b)
-	n := decomps[p]
-	p++
-	return decomps[p : p+uint16(n)]
-}
-
-func decomposeStringNFC(s string) []byte {
-	p := nfcDecompTrie.lookupStringUnsafe(s)
-	n := decomps[p]
-	p++
-	return decomps[p : p+uint16(n)]
-}
-
-func decomposeStringNFKC(s string) []byte {
-	p := nfkcDecompTrie.lookupStringUnsafe(s)
+func decomposeNFKC(s input, i int) []byte {
+	p := s.decomposeNFKC(i)
 	n := decomps[p]
 	p++
 	return decomps[p : p+uint16(n)]
@@ -168,22 +146,12 @@ func combine(a, b uint32) uint32 {
 //    0..7   CCC value.
 //    8..11  qcInfo for NFC/NFD
 //   12..15  qcInfo for NFKC/NFKD
-func lookupInfoNFC(b []byte) runeInfo {
-	v, sz := charInfoTrie.lookup(b)
-	return runeInfo{0, uint8(sz), uint8(v), qcInfo(v >> 8)}
-}
-
-func lookupInfoStringNFC(s string) runeInfo {
-	v, sz := charInfoTrie.lookupString(s)
+func lookupInfoNFC(b input, i int) runeInfo {
+	v, sz := b.charinfo(i)
 	return runeInfo{0, uint8(sz), uint8(v), qcInfo(v >> 8)}
 }
 
-func lookupInfoNFKC(b []byte) runeInfo {
-	v, sz := charInfoTrie.lookup(b)
-	return runeInfo{0, uint8(sz), uint8(v), qcInfo(v >> 12)}
-}
-
-func lookupInfoStringNFKC(s string) runeInfo {
-	v, sz := charInfoTrie.lookupString(s)
+func lookupInfoNFKC(b input, i int) runeInfo {
+	v, sz := b.charinfo(i)
 	return runeInfo{0, uint8(sz), uint8(v), qcInfo(v >> 12)}
 }

src/pkg/exp/norm/input.go

+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package norm
+
+import "utf8"
+
+type input interface {
+	skipASCII(p int) int
+	skipNonStarter() int
+	appendSlice(buf []byte, s, e int) []byte
+	copySlice(buf []byte, s, e int)
+	charinfo(p int) (uint16, int)
+	decomposeNFC(p int) uint16
+	decomposeNFKC(p int) uint16
+	hangul(p int) uint32
+}
+
+type inputString string
+
+func (s inputString) skipASCII(p int) int {
+	for ; p < len(s) && s[p] < utf8.RuneSelf; p++ {
+	}
+	return p
+}
+
+func (s inputString) skipNonStarter() int {
+	p := 0
+	for ; p < len(s) && !utf8.RuneStart(s[p]); p++ {
+	}
+	return p
+}
+
+func (s inputString) appendSlice(buf []byte, b, e int) []byte {
+	for i := b; i < e; i++ {
+		buf = append(buf, s[i])
+	}
+	return buf
+}
+
+func (s inputString) copySlice(buf []byte, b, e int) {
+	copy(buf, s[b:e])
+}
+
+func (s inputString) charinfo(p int) (uint16, int) {
+	return charInfoTrie.lookupString(string(s[p:]))
+}
+
+func (s inputString) decomposeNFC(p int) uint16 {
+	return nfcDecompTrie.lookupStringUnsafe(string(s[p:]))
+}
+
+func (s inputString) decomposeNFKC(p int) uint16 {
+	return nfkcDecompTrie.lookupStringUnsafe(string(s[p:]))
+}
+
+func (s inputString) hangul(p int) uint32 {
+	if !isHangulString(string(s[p:])) {
+		return 0
+	}
+	rune, _ := utf8.DecodeRuneInString(string(s[p:]))
+	return uint32(rune)
+}
+
+type inputBytes []byte
+
+func (s inputBytes) skipASCII(p int) int {
+	for ; p < len(s) && s[p] < utf8.RuneSelf; p++ {
+	}
+	return p
+}
+
+func (s inputBytes) skipNonStarter() int {
+	p := 0
+	for ; p < len(s) && !utf8.RuneStart(s[p]); p++ {
+	}
+	return p
+}
+
+func (s inputBytes) appendSlice(buf []byte, b, e int) []byte {
+	return append(buf, s[b:e]...)
+}
+
+func (s inputBytes) copySlice(buf []byte, b, e int) {
+	copy(buf, s[b:e])
+}
+
+func (s inputBytes) charinfo(p int) (uint16, int) {
+	return charInfoTrie.lookup(s[p:])
+}
+
+func (s inputBytes) decomposeNFC(p int) uint16 {
+	return nfcDecompTrie.lookupUnsafe(s[p:])
+}
+
+func (s inputBytes) decomposeNFKC(p int) uint16 {
+	return nfkcDecompTrie.lookupUnsafe(s[p:])
+}
+
+func (s inputBytes) hangul(p int) uint32 {
+	if !isHangul(s[p:]) {
+		return 0
+	}
+	rune, _ := utf8.DecodeRune(s[p:])
+	return uint32(rune)
+}

src/pkg/exp/norm/normalize.go

@@ -56,15 +56,15 @@ func (f Form) String(s string) string {
 
 // IsNormal returns true if b == f(b).
 func (f Form) IsNormal(b []byte) bool {
-	fd := formTable[f]
-	bp := quickSpan(fd, b)
+	rb := reorderBuffer{}
+	rb.init(f, b)
+	bp := quickSpan(&rb, 0)
 	if bp == len(b) {
 		return true
 	}
-	rb := reorderBuffer{f: *fd}
 	for bp < len(b) {
-		decomposeSegment(&rb, b[bp:])
-		if fd.composing {
+		decomposeSegment(&rb, bp)
+		if rb.f.composing {
 			rb.compose()
 		}
 		for i := 0; i < rb.nrune; i++ {
@@ -82,14 +82,42 @@ func (f Form) IsNormal(b []byte) bool {
 			}
 		}
 		rb.reset()
-		bp += quickSpan(fd, b[bp:])
+		bp = quickSpan(&rb, bp)
 	}
 	return true
 }
 
 // IsNormalString returns true if s == f(s).
 func (f Form) IsNormalString(s string) bool {
-	panic("not implemented")
+	rb := reorderBuffer{}
+	rb.initString(f, s)
+	bp := quickSpan(&rb, 0)
+	if bp == len(s) {
+		return true
+	}
+	for bp < len(s) {
+		decomposeSegment(&rb, bp)
+		if rb.f.composing {
+			rb.compose()
+		}
+		for i := 0; i < rb.nrune; i++ {
+			info := rb.rune[i]
+			if bp+int(info.size) > len(s) {
+				return false
+			}
+			p := info.pos
+			pe := p + info.size
+			for ; p < pe; p++ {
+				if s[bp] != rb.byte[p] {
+					return false
+				}
+				bp++
+			}
+		}
+		rb.reset()
+		bp = quickSpan(&rb, bp)
+	}
+	return true
 }
 
 // patchTail fixes a case where a rune may be incorrectly normalized
@@ -113,12 +141,12 @@ func patchTail(rb *reorderBuffer, buf []byte) ([]byte, int) {
 	return buf, 0
 }
 
-func appendQuick(f *formInfo, dst, src []byte) ([]byte, int) {
-	if len(src) == 0 {
-		return dst, 0
+func appendQuick(rb *reorderBuffer, dst []byte, i int) ([]byte, int) {
+	if rb.nsrc == i {
+		return dst, i
 	}
-	end := quickSpan(f, src)
-	return append(dst, src[:end]...), end
+	end := quickSpan(rb, i)
+	return rb.src.appendSlice(dst, i, end), end
 }
 
 // Append returns f(append(out, b...)).
@@ -127,22 +155,21 @@ func (f Form) Append(out []byte, src ...byte) []byte {
 	if len(src) == 0 {
 		return out
 	}
-	fd := formTable[f]
-	rb := &reorderBuffer{f: *fd}
-	return doAppend(rb, out, src)
+	rb := reorderBuffer{}
+	rb.init(f, src)
+	return doAppend(&rb, out)
 }
 
-func doAppend(rb *reorderBuffer, out, src []byte) []byte {
+func doAppend(rb *reorderBuffer, out []byte) []byte {
+	src, n := rb.src, rb.nsrc
 	doMerge := len(out) > 0
 	p := 0
-	if !utf8.RuneStart(src[0]) {
+	if p = src.skipNonStarter(); p > 0 {
 		// Move leading non-starters to destination.
-		for p++; p < len(src) && !utf8.RuneStart(src[p]); p++ {
-		}
-		out = append(out, src[:p]...)
+		out = src.appendSlice(out, 0, p)
 		buf, ndropped := patchTail(rb, out)
 		if ndropped > 0 {
-			out = append(buf, src[p-ndropped:p]...)
+			out = src.appendSlice(buf, p-ndropped, p)
 			doMerge = false // no need to merge, ends with illegal UTF-8
 		} else {
 			out = decomposeToLastBoundary(rb, buf) // force decomposition
@@ -151,8 +178,8 @@ func doAppend(rb *reorderBuffer, out, src []byte) []byte {
 	fd := &rb.f
 	if doMerge {
 		var info runeInfo
-		if p < len(src) {
-			info = fd.info(src[p:])
+		if p < n {
+			info = fd.info(src, p)
 			if p == 0 && !fd.boundaryBefore(fd, info) {
 				out = decomposeToLastBoundary(rb, out)
 			}
@@ -164,59 +191,63 @@ func doAppend(rb *reorderBuffer, out, src []byte) []byte {
 			out = rb.flush(out)
 			if info.size == 0 {
 				// Append incomplete UTF-8 encoding.
-				return append(out, src[p:]...)
+				return src.appendSlice(out, p, n)
 			}
 		}
 	}
 	if rb.nrune == 0 {
-		src = src[p:]
-		out, p = appendQuick(fd, out, src)
+		out, p = appendQuick(rb, out, p)
 	}
-	for n := 0; p < len(src); p += n {
-		p += decomposeSegment(rb, src[p:])
+	for p < n {
+		p = decomposeSegment(rb, p)
 		if fd.composing {
 			rb.compose()
 		}
 		out = rb.flush(out)
-		out, n = appendQuick(fd, out, src[p:])
+		out, p = appendQuick(rb, out, p)
 	}
 	return out
 }
 
 // AppendString returns f(append(out, []byte(s))).
 // The buffer out must be nil, empty, or equal to f(out).
-func (f Form) AppendString(out []byte, s string) []byte {
-	panic("not implemented")
+func (f Form) AppendString(out []byte, src string) []byte {
+	if len(src) == 0 {
+		return out
+	}
+	rb := reorderBuffer{}
+	rb.initString(f, src)
+	return doAppend(&rb, out)
 }
 
 // QuickSpan returns a boundary n such that b[0:n] == f(b[0:n]).
 // It is not guaranteed to return the largest such n.
 func (f Form) QuickSpan(b []byte) int {
-	return quickSpan(formTable[f], b)
+	rb := reorderBuffer{}
+	rb.init(f, b)
+	return quickSpan(&rb, 0)
 }
 
-func quickSpan(fd *formInfo, b []byte) int {
+func quickSpan(rb *reorderBuffer, i int) int {
 	var lastCC uint8
-	var lastSegStart int
-	var i, nc int
-	for i < len(b) {
-		if b[i] < utf8.RuneSelf {
-			// Keep the loop tight for ASCII processing, as this is where
-			// most of the time is spent for this case.
-			for i++; i < len(b) && b[i] < utf8.RuneSelf; i++ {
-			}
+	var nc int
+	lastSegStart := i
+	src, n := rb.src, rb.nsrc
+	for i < n {
+		if j := src.skipASCII(i); i != j {
+			i = j
 			lastSegStart = i - 1
 			lastCC = 0
 			nc = 0
 			continue
 		}
-		info := fd.info(b[i:])
+		info := rb.f.info(src, i)
 		if info.size == 0 {
 			// include incomplete runes
-			return len(b)
+			return n
 		}
 		cc := info.ccc
-		if fd.composing {
+		if rb.f.composing {
 			if !info.flags.isYesC() {
 				break
 			}
@@ -243,10 +274,10 @@ func quickSpan(fd *formInfo, b []byte) int {
 		lastCC = cc
 		i += int(info.size)
 	}
-	if i == len(b) {
-		return len(b)
+	if i == n {
+		return n
 	}
-	if fd.composing {
+	if rb.f.composing {
 		return lastSegStart
 	}
 	return i
@@ -255,32 +286,39 @@ func quickSpan(fd *formInfo, b []byte) int {
 // QuickSpanString returns a boundary n such that b[0:n] == f(s[0:n]).
 // It is not guaranteed to return the largest such n.
 func (f Form) QuickSpanString(s string) int {
-	panic("not implemented")
+	rb := reorderBuffer{}
+	rb.initString(f, s)
+	return quickSpan(&rb, 0)
 }
 
 // FirstBoundary returns the position i of the first boundary in b
 // or -1 if b contains no boundary.
 func (f Form) FirstBoundary(b []byte) int {
-	i := 0
-	for ; i < len(b) && !utf8.RuneStart(b[i]); i++ {
-	}
-	if i >= len(b) {
+	rb := reorderBuffer{}
+	rb.init(f, b)
+	return firstBoundary(&rb)
+}
+
+func firstBoundary(rb *reorderBuffer) int {
+	src, nsrc := rb.src, rb.nsrc
+	i := src.skipNonStarter()
+	if i >= nsrc {
 		return -1
 	}
-	fd := formTable[f]
-	info := fd.info(b[i:])
+	fd := &rb.f
+	info := fd.info(src, i)
 	for n := 0; info.size != 0 && !fd.boundaryBefore(fd, info); {
 		i += int(info.size)
 		if n++; n >= maxCombiningChars {
 			return i
 		}
-		if i >= len(b) {
+		if i >= nsrc {
 			if !fd.boundaryAfter(fd, info) {
 				return -1
 			}
-			return len(b)
+			return nsrc
 		}
-		info = fd.info(b[i:])
+		info = fd.info(src, i)
 	}
 	if info.size == 0 {
 		return -1
@@ -290,8 +328,10 @@ func (f Form) FirstBoundary(b []byte) int {
 
 // FirstBoundaryInString returns the position i of the first boundary in s
 // or -1 if s contains no boundary.
-func (f Form) FirstBoundaryInString(s string) (i int, ok bool) {
-	panic("not implemented")
+func (f Form) FirstBoundaryInString(s string) int {
+	rb := reorderBuffer{}
+	rb.initString(f, s)
+	return firstBoundary(&rb)
 }
 
 // LastBoundary returns the position i of the last boundary in b
@@ -349,19 +389,18 @@ func (f Form) LastBoundaryInString(s string) int {
 // It returns the number of bytes consumed from src.
 // TODO(mpvl): consider inserting U+034f (Combining Grapheme Joiner)
 // when we detect a sequence of 30+ non-starter chars.
-func decomposeSegment(rb *reorderBuffer, src []byte) int {
+func decomposeSegment(rb *reorderBuffer, sp int) int {
 	// Force one character to be consumed.
-	info := rb.f.info(src)
+	info := rb.f.info(rb.src, sp)
 	if info.size == 0 {
 		return 0
 	}
-	sp := 0
-	for rb.insert(src[sp:], info) {
+	for rb.insert(rb.src, sp, info) {
 		sp += int(info.size)
-		if sp >= len(src) {
+		if sp >= rb.nsrc {
 			break
 		}
-		info = rb.f.info(src[sp:])
+		info = rb.f.info(rb.src, sp)
 		bound := rb.f.boundaryBefore(&rb.f, info)
 		if bound || info.size == 0 {
 			break
@@ -379,7 +418,7 @@ func lastRuneStart(fd *formInfo, buf []byte) (runeInfo, int) {
 	if p < 0 {
 		return runeInfo{0, 0, 0, 0}, -1
 	}
-	return fd.info(buf[p:]), p
+	return fd.info(inputBytes(buf), p), p
 }
 
 // decomposeToLastBoundary finds an open segment at the end of the buffer
@@ -406,9 +445,9 @@ func decomposeToLastBoundary(rb *reorderBuffer, buf []byte) []byte {
 		}
 		// Check that decomposition doesn't result in overflow.
 		if info.flags.hasDecomposition() {
-			dcomp := rb.f.decompose(buf[p-int(info.size):])
+			dcomp := rb.f.decompose(inputBytes(buf), p-int(info.size))
 			for i := 0; i < len(dcomp); {
-				inf := rb.f.info(dcomp[i:])
+				inf := rb.f.info(inputBytes(dcomp), i)
 				i += int(inf.size)
 				n++
 			}
@@ -424,7 +463,7 @@ func decomposeToLastBoundary(rb *reorderBuffer, buf []byte) []byte {
 	pp := p
 	for padd--; padd >= 0; padd-- {
 		info = add[padd]
-		rb.insert(buf[pp:], info)
+		rb.insert(inputBytes(buf), pp, info)
 		pp += int(info.size)
 	}
 	return buf[:p]

src/pkg/exp/norm/normalize_test.go

@@ -18,9 +18,12 @@ type PositionTest struct {
 type positionFunc func(rb *reorderBuffer, s string) int
 
 func runPosTests(t *testing.T, name string, f Form, fn positionFunc, tests []PositionTest) {
-	rb := reorderBuffer{f: *formTable[f]}
+	rb := reorderBuffer{}
+	rb.init(f, nil)
 	for i, test := range tests {
 		rb.reset()
+		rb.src = inputString(test.input)
+		rb.nsrc = len(test.input)
 		pos := fn(&rb, test.input)
 		if pos != test.pos {
 			t.Errorf("%s:%d: position is %d; want %d", name, i, pos, test.pos)
@@ -60,7 +63,9 @@ var decomposeSegmentTests = []PositionTest{
 }
 
 func decomposeSegmentF(rb *reorderBuffer, s string) int {
-	return decomposeSegment(rb, []byte(s))
+	rb.src = inputString(s)
+	rb.nsrc = len(s)
+	return decomposeSegment(rb, 0)
 }
 
 func TestDecomposeSegment(t *testing.T) {
@@ -90,12 +95,17 @@ var firstBoundaryTests = []PositionTest{
 	{strings.Repeat("\u0300", maxCombiningChars+1), 60, ""},
 }
 
-func firstBoundary(rb *reorderBuffer, s string) int {
+func firstBoundaryF(rb *reorderBuffer, s string) int {
 	return rb.f.form.FirstBoundary([]byte(s))
 }
 
+func firstBoundaryStringF(rb *reorderBuffer, s string) int {
+	return rb.f.form.FirstBoundaryInString(s)
+}
+
 func TestFirstBoundary(t *testing.T) {
-	runPosTests(t, "TestFirstBoundary", NFC, firstBoundary, firstBoundaryTests)
+	runPosTests(t, "TestFirstBoundary", NFC, firstBoundaryF, firstBoundaryTests)
+	runPosTests(t, "TestFirstBoundaryInString", NFC, firstBoundaryStringF, firstBoundaryTests)
 }
 
 var decomposeToLastTests = []PositionTest{
@@ -275,11 +285,20 @@ func doQuickSpan(rb *reorderBuffer, s string) int {
 	return rb.f.form.QuickSpan([]byte(s))
 }
 
+func doQuickSpanString(rb *reorderBuffer, s string) int {
+	return rb.f.form.QuickSpanString(s)
+}
+
 func TestQuickSpan(t *testing.T) {
 	runPosTests(t, "TestQuickSpanNFD1", NFD, doQuickSpan, quickSpanTests)
 	runPosTests(t, "TestQuickSpanNFD2", NFD, doQuickSpan, quickSpanNFDTests)
 	runPosTests(t, "TestQuickSpanNFC1", NFC, doQuickSpan, quickSpanTests)
 	runPosTests(t, "TestQuickSpanNFC2", NFC, doQuickSpan, quickSpanNFCTests)
+
+	runPosTests(t, "TestQuickSpanStringNFD1", NFD, doQuickSpanString, quickSpanTests)
+	runPosTests(t, "TestQuickSpanStringNFD2", NFD, doQuickSpanString, quickSpanNFDTests)
+	runPosTests(t, "TestQuickSpanStringNFC1", NFC, doQuickSpanString, quickSpanTests)
+	runPosTests(t, "TestQuickSpanStringNFC2", NFC, doQuickSpanString, quickSpanNFCTests)
 }
 
 var isNormalTests = []PositionTest{
@@ -334,7 +353,7 @@ var isNormalNFCTests = []PositionTest{
 	{"같은", 1, ""},
 }
 
-func isNormal(rb *reorderBuffer, s string) int {
+func isNormalF(rb *reorderBuffer, s string) int {
 	if rb.f.form.IsNormal([]byte(s)) {
 		return 1
 	}
@@ -342,10 +361,10 @@ func isNormal(rb *reorderBuffer, s string) int {
 }
 
 func TestIsNormal(t *testing.T) {
-	runPosTests(t, "TestIsNormalNFD1", NFD, isNormal, isNormalTests)
-	runPosTests(t, "TestIsNormalNFD2", NFD, isNormal, isNormalNFDTests)
-	runPosTests(t, "TestIsNormalNFC1", NFC, isNormal, isNormalTests)
-	runPosTests(t, "TestIsNormalNFC2", NFC, isNormal, isNormalNFCTests)
+	runPosTests(t, "TestIsNormalNFD1", NFD, isNormalF, isNormalTests)
+	runPosTests(t, "TestIsNormalNFD2", NFD, isNormalF, isNormalNFDTests)
+	runPosTests(t, "TestIsNormalNFC1", NFC, isNormalF, isNormalTests)
+	runPosTests(t, "TestIsNormalNFC2", NFC, isNormalF, isNormalNFCTests)
 }
 
 type AppendTest struct {
@@ -452,8 +471,13 @@ func appendF(f Form, out []byte, s string) []byte {
 	return f.Append(out, []byte(s)...)
 }
 
+func appendStringF(f Form, out []byte, s string) []byte {
+	return f.AppendString(out, s)
+}
+
 func TestAppend(t *testing.T) {
 	runAppendTests(t, "TestAppend", NFKC, appendF, appendTests)
+	runAppendTests(t, "TestAppendString", NFKC, appendStringF, appendTests)
 }
 
 func doFormBenchmark(b *testing.B, f Form, s string) {

src/pkg/exp/norm/readwriter.go

@@ -28,7 +28,9 @@ func (w *normWriter) Write(data []byte) (n int, err os.Error) {
 		if m > chunk {
 			m = chunk
 		}
-		w.buf = doAppend(&w.rb, w.buf, data[:m])
+		w.rb.src = inputBytes(data[:m])
+		w.rb.nsrc = m
+		w.buf = doAppend(&w.rb, w.buf)
 		data = data[m:]
 		n += m
 
@@ -65,7 +67,9 @@ func (w *normWriter) Close() os.Error {
 // an internal buffer to maintain state across Write calls.
 // Calling its Close method writes any buffered data to w.
 func (f Form) Writer(w io.Writer) io.WriteCloser {
-	return &normWriter{rb: reorderBuffer{f: *formTable[f]}, w: w}
+	wr := &normWriter{rb: reorderBuffer{}, w: w}
+	wr.rb.init(f, nil)
+	return wr
 }
 
 type normReader struct {
@@ -97,9 +101,10 @@ func (r *normReader) Read(p []byte) (int, os.Error) {
 		r.bufStart = 0
 
 		n, err := r.r.Read(r.inbuf)
-		r.err = err // save error for when done with buffer
+		r.rb.src = inputBytes(r.inbuf[0:n])
+		r.rb.nsrc, r.err = n, err
 		if n > 0 {
-			r.outbuf = doAppend(&r.rb, r.outbuf, r.inbuf[0:n])
+			r.outbuf = doAppend(&r.rb, r.outbuf)
 		}
 		if err == os.EOF {
 			r.lastBoundary = len(r.outbuf)
@@ -117,5 +122,8 @@ func (r *normReader) Read(p []byte) (int, os.Error) {
 // by reading data from r and returning f(data).
 func (f Form) Reader(r io.Reader) io.Reader {
 	const chunk = 4000
-	return &normReader{rb: reorderBuffer{f: *formTable[f]}, r: r, inbuf: make([]byte, chunk)}
+	buf := make([]byte, chunk)
+	rr := &normReader{rb: reorderBuffer{}, r: r, inbuf: buf}
+	rr.rb.init(f, buf)
+	return rr
 }