From 404aeae4545d2426c089a5f8d5e82dae56f5212b Mon Sep 17 00:00:00 2001
From: Rutger Broekhoff
Date: Fri, 29 Dec 2023 21:31:53 +0100
Subject: Make Nix builds work

---
 .../golang.org/x/text/unicode/norm/composition.go  | 512 +++++++++++++++++++++
 1 file changed, 512 insertions(+)
 create mode 100644 vendor/golang.org/x/text/unicode/norm/composition.go

(limited to 'vendor/golang.org/x/text/unicode/norm/composition.go')

diff --git a/vendor/golang.org/x/text/unicode/norm/composition.go b/vendor/golang.org/x/text/unicode/norm/composition.go
new file mode 100644
index 0000000..e2087bc
--- /dev/null
+++ b/vendor/golang.org/x/text/unicode/norm/composition.go
@@ -0,0 +1,512 @@
+// 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 "unicode/utf8"
+
+const (
+	maxNonStarters = 30
+	// The maximum number of characters needed for a buffer is
+	// maxNonStarters + 1 for the starter + 1 for the GCJ
+	maxBufferSize    = maxNonStarters + 2
+	maxNFCExpansion  = 3  // NFC(0x1D160)
+	maxNFKCExpansion = 18 // NFKC(0xFDFA)
+
+	maxByteBufferSize = utf8.UTFMax * maxBufferSize // 128
+)
+
+// ssState is used for reporting the segment state after inserting a rune.
+// It is returned by streamSafe.next.
+type ssState int
+
+const (
+	// Indicates a rune was successfully added to the segment.
+	ssSuccess ssState = iota
+	// Indicates a rune starts a new segment and should not be added.
+	ssStarter
+	// Indicates a rune caused a segment overflow and a CGJ should be inserted.
+	ssOverflow
+)
+
+// streamSafe implements the policy of when a CGJ should be inserted.
+type streamSafe uint8
+
+// first inserts the first rune of a segment. It is a faster version of next if
+// it is known p represents the first rune in a segment.
+func (ss *streamSafe) first(p Properties) {
+	*ss = streamSafe(p.nTrailingNonStarters())
+}
+
+// insert returns a ssState value to indicate whether a rune represented by p
+// can be inserted.
+func (ss *streamSafe) next(p Properties) ssState {
+	if *ss > maxNonStarters {
+		panic("streamSafe was not reset")
+	}
+	n := p.nLeadingNonStarters()
+	if *ss += streamSafe(n); *ss > maxNonStarters {
+		*ss = 0
+		return ssOverflow
+	}
+	// The Stream-Safe Text Processing prescribes that the counting can stop
+	// as soon as a starter is encountered. However, there are some starters,
+	// like Jamo V and T, that can combine with other runes, leaving their
+	// successive non-starters appended to the previous, possibly causing an
+	// overflow. We will therefore consider any rune with a non-zero nLead to
+	// be a non-starter. Note that it always hold that if nLead > 0 then
+	// nLead == nTrail.
+	if n == 0 {
+		*ss = streamSafe(p.nTrailingNonStarters())
+		return ssStarter
+	}
+	return ssSuccess
+}
+
+// backwards is used for checking for overflow and segment starts
+// when traversing a string backwards. Users do not need to call first
+// for the first rune. The state of the streamSafe retains the count of
+// the non-starters loaded.
+func (ss *streamSafe) backwards(p Properties) ssState {
+	if *ss > maxNonStarters {
+		panic("streamSafe was not reset")
+	}
+	c := *ss + streamSafe(p.nTrailingNonStarters())
+	if c > maxNonStarters {
+		return ssOverflow
+	}
+	*ss = c
+	if p.nLeadingNonStarters() == 0 {
+		return ssStarter
+	}
+	return ssSuccess
+}
+
+func (ss streamSafe) isMax() bool {
+	return ss == maxNonStarters
+}
+
+// GraphemeJoiner is inserted after maxNonStarters non-starter runes.
+const GraphemeJoiner = "\u034F"
+
+// reorderBuffer is used to normalize a single segment.  Characters inserted with
+// insert are decomposed and reordered based on CCC. The compose method can
+// be used to recombine characters.  Note that the byte buffer does not hold
+// the UTF-8 characters in order.  Only the rune array is maintained in sorted
+// order. flush writes the resulting segment to a byte array.
+type reorderBuffer struct {
+	rune  [maxBufferSize]Properties // Per character info.
+	byte  [maxByteBufferSize]byte   // UTF-8 buffer. Referenced by runeInfo.pos.
+	nbyte uint8                     // Number or bytes.
+	ss    streamSafe                // For limiting length of non-starter sequence.
+	nrune int                       // Number of runeInfos.
+	f     formInfo
+
+	src      input
+	nsrc     int
+	tmpBytes input
+
+	out    []byte
+	flushF func(*reorderBuffer) bool
+}
+
+func (rb *reorderBuffer) init(f Form, src []byte) {
+	rb.f = *formTable[f]
+	rb.src.setBytes(src)
+	rb.nsrc = len(src)
+	rb.ss = 0
+}
+
+func (rb *reorderBuffer) initString(f Form, src string) {
+	rb.f = *formTable[f]
+	rb.src.setString(src)
+	rb.nsrc = len(src)
+	rb.ss = 0
+}
+
+func (rb *reorderBuffer) setFlusher(out []byte, f func(*reorderBuffer) bool) {
+	rb.out = out
+	rb.flushF = f
+}
+
+// reset discards all characters from the buffer.
+func (rb *reorderBuffer) reset() {
+	rb.nrune = 0
+	rb.nbyte = 0
+}
+
+func (rb *reorderBuffer) doFlush() bool {
+	if rb.f.composing {
+		rb.compose()
+	}
+	res := rb.flushF(rb)
+	rb.reset()
+	return res
+}
+
+// appendFlush appends the normalized segment to rb.out.
+func appendFlush(rb *reorderBuffer) bool {
+	for i := 0; i < rb.nrune; i++ {
+		start := rb.rune[i].pos
+		end := start + rb.rune[i].size
+		rb.out = append(rb.out, rb.byte[start:end]...)
+	}
+	return true
+}
+
+// flush appends the normalized segment to out and resets rb.
+func (rb *reorderBuffer) flush(out []byte) []byte {
+	for i := 0; i < rb.nrune; i++ {
+		start := rb.rune[i].pos
+		end := start + rb.rune[i].size
+		out = append(out, rb.byte[start:end]...)
+	}
+	rb.reset()
+	return out
+}
+
+// flushCopy copies the normalized segment to buf and resets rb.
+// It returns the number of bytes written to buf.
+func (rb *reorderBuffer) flushCopy(buf []byte) int {
+	p := 0
+	for i := 0; i < rb.nrune; i++ {
+		runep := rb.rune[i]
+		p += copy(buf[p:], rb.byte[runep.pos:runep.pos+runep.size])
+	}
+	rb.reset()
+	return p
+}
+
+// insertOrdered inserts a rune in the buffer, ordered by Canonical Combining Class.
+// It returns false if the buffer is not large enough to hold the rune.
+// It is used internally by insert and insertString only.
+func (rb *reorderBuffer) insertOrdered(info Properties) {
+	n := rb.nrune
+	b := rb.rune[:]
+	cc := info.ccc
+	if cc > 0 {
+		// Find insertion position + move elements to make room.
+		for ; n > 0; n-- {
+			if b[n-1].ccc <= cc {
+				break
+			}
+			b[n] = b[n-1]
+		}
+	}
+	rb.nrune += 1
+	pos := uint8(rb.nbyte)
+	rb.nbyte += utf8.UTFMax
+	info.pos = pos
+	b[n] = info
+}
+
+// insertErr is an error code returned by insert. Using this type instead
+// of error improves performance up to 20% for many of the benchmarks.
+type insertErr int
+
+const (
+	iSuccess insertErr = -iota
+	iShortDst
+	iShortSrc
+)
+
+// insertFlush inserts the given rune in the buffer ordered by CCC.
+// If a decomposition with multiple segments are encountered, they leading
+// ones are flushed.
+// It returns a non-zero error code if the rune was not inserted.
+func (rb *reorderBuffer) insertFlush(src input, i int, info Properties) insertErr {
+	if rune := src.hangul(i); rune != 0 {
+		rb.decomposeHangul(rune)
+		return iSuccess
+	}
+	if info.hasDecomposition() {
+		return rb.insertDecomposed(info.Decomposition())
+	}
+	rb.insertSingle(src, i, info)
+	return iSuccess
+}
+
+// insertUnsafe inserts the given rune in the buffer ordered by CCC.
+// It is assumed there is sufficient space to hold the runes. It is the
+// responsibility of the caller to ensure this. This can be done by checking
+// the state returned by the streamSafe type.
+func (rb *reorderBuffer) insertUnsafe(src input, i int, info Properties) {
+	if rune := src.hangul(i); rune != 0 {
+		rb.decomposeHangul(rune)
+	}
+	if info.hasDecomposition() {
+		// TODO: inline.
+		rb.insertDecomposed(info.Decomposition())
+	} else {
+		rb.insertSingle(src, i, info)
+	}
+}
+
+// insertDecomposed inserts an entry in to the reorderBuffer for each rune
+// in dcomp. dcomp must be a sequence of decomposed UTF-8-encoded runes.
+// It flushes the buffer on each new segment start.
+func (rb *reorderBuffer) insertDecomposed(dcomp []byte) insertErr {
+	rb.tmpBytes.setBytes(dcomp)
+	// As the streamSafe accounting already handles the counting for modifiers,
+	// we don't have to call next. However, we do need to keep the accounting
+	// intact when flushing the buffer.
+	for i := 0; i < len(dcomp); {
+		info := rb.f.info(rb.tmpBytes, i)
+		if info.BoundaryBefore() && rb.nrune > 0 && !rb.doFlush() {
+			return iShortDst
+		}
+		i += copy(rb.byte[rb.nbyte:], dcomp[i:i+int(info.size)])
+		rb.insertOrdered(info)
+	}
+	return iSuccess
+}
+
+// insertSingle inserts an entry in the reorderBuffer for the rune at
+// position i. info is the runeInfo for the rune at position i.
+func (rb *reorderBuffer) insertSingle(src input, i int, info Properties) {
+	src.copySlice(rb.byte[rb.nbyte:], i, i+int(info.size))
+	rb.insertOrdered(info)
+}
+
+// insertCGJ inserts a Combining Grapheme Joiner (0x034f) into rb.
+func (rb *reorderBuffer) insertCGJ() {
+	rb.insertSingle(input{str: GraphemeJoiner}, 0, Properties{size: uint8(len(GraphemeJoiner))})
+}
+
+// appendRune inserts a rune at the end of the buffer. It is used for Hangul.
+func (rb *reorderBuffer) appendRune(r rune) {
+	bn := rb.nbyte
+	sz := utf8.EncodeRune(rb.byte[bn:], rune(r))
+	rb.nbyte += utf8.UTFMax
+	rb.rune[rb.nrune] = Properties{pos: bn, size: uint8(sz)}
+	rb.nrune++
+}
+
+// assignRune sets a rune at position pos. It is used for Hangul and recomposition.
+func (rb *reorderBuffer) assignRune(pos int, r rune) {
+	bn := rb.rune[pos].pos
+	sz := utf8.EncodeRune(rb.byte[bn:], rune(r))
+	rb.rune[pos] = Properties{pos: bn, size: uint8(sz)}
+}
+
+// runeAt returns the rune at position n. It is used for Hangul and recomposition.
+func (rb *reorderBuffer) runeAt(n int) rune {
+	inf := rb.rune[n]
+	r, _ := utf8.DecodeRune(rb.byte[inf.pos : inf.pos+inf.size])
+	return r
+}
+
+// bytesAt returns the UTF-8 encoding of the rune at position n.
+// It is used for Hangul and recomposition.
+func (rb *reorderBuffer) bytesAt(n int) []byte {
+	inf := rb.rune[n]
+	return rb.byte[inf.pos : int(inf.pos)+int(inf.size)]
+}
+
+// For Hangul we combine algorithmically, instead of using tables.
+const (
+	hangulBase  = 0xAC00 // UTF-8(hangulBase) -> EA B0 80
+	hangulBase0 = 0xEA
+	hangulBase1 = 0xB0
+	hangulBase2 = 0x80
+
+	hangulEnd  = hangulBase + jamoLVTCount // UTF-8(0xD7A4) -> ED 9E A4
+	hangulEnd0 = 0xED
+	hangulEnd1 = 0x9E
+	hangulEnd2 = 0xA4
+
+	jamoLBase  = 0x1100 // UTF-8(jamoLBase) -> E1 84 00
+	jamoLBase0 = 0xE1
+	jamoLBase1 = 0x84
+	jamoLEnd   = 0x1113
+	jamoVBase  = 0x1161
+	jamoVEnd   = 0x1176
+	jamoTBase  = 0x11A7
+	jamoTEnd   = 0x11C3
+
+	jamoTCount   = 28
+	jamoVCount   = 21
+	jamoVTCount  = 21 * 28
+	jamoLVTCount = 19 * 21 * 28
+)
+
+const hangulUTF8Size = 3
+
+func isHangul(b []byte) bool {
+	if len(b) < hangulUTF8Size {
+		return false
+	}
+	b0 := b[0]
+	if b0 < hangulBase0 {
+		return false
+	}
+	b1 := b[1]
+	switch {
+	case b0 == hangulBase0:
+		return b1 >= hangulBase1
+	case b0 < hangulEnd0:
+		return true
+	case b0 > hangulEnd0:
+		return false
+	case b1 < hangulEnd1:
+		return true
+	}
+	return b1 == hangulEnd1 && b[2] < hangulEnd2
+}
+
+func isHangulString(b string) bool {
+	if len(b) < hangulUTF8Size {
+		return false
+	}
+	b0 := b[0]
+	if b0 < hangulBase0 {
+		return false
+	}
+	b1 := b[1]
+	switch {
+	case b0 == hangulBase0:
+		return b1 >= hangulBase1
+	case b0 < hangulEnd0:
+		return true
+	case b0 > hangulEnd0:
+		return false
+	case b1 < hangulEnd1:
+		return true
+	}
+	return b1 == hangulEnd1 && b[2] < hangulEnd2
+}
+
+// Caller must ensure len(b) >= 2.
+func isJamoVT(b []byte) bool {
+	// True if (rune & 0xff00) == jamoLBase
+	return b[0] == jamoLBase0 && (b[1]&0xFC) == jamoLBase1
+}
+
+func isHangulWithoutJamoT(b []byte) bool {
+	c, _ := utf8.DecodeRune(b)
+	c -= hangulBase
+	return c < jamoLVTCount && c%jamoTCount == 0
+}
+
+// decomposeHangul writes the decomposed Hangul to buf and returns the number
+// of bytes written.  len(buf) should be at least 9.
+func decomposeHangul(buf []byte, r rune) int {
+	const JamoUTF8Len = 3
+	r -= hangulBase
+	x := r % jamoTCount
+	r /= jamoTCount
+	utf8.EncodeRune(buf, jamoLBase+r/jamoVCount)
+	utf8.EncodeRune(buf[JamoUTF8Len:], jamoVBase+r%jamoVCount)
+	if x != 0 {
+		utf8.EncodeRune(buf[2*JamoUTF8Len:], jamoTBase+x)
+		return 3 * JamoUTF8Len
+	}
+	return 2 * JamoUTF8Len
+}
+
+// decomposeHangul algorithmically decomposes a Hangul rune into
+// its Jamo components.
+// See https://unicode.org/reports/tr15/#Hangul for details on decomposing Hangul.
+func (rb *reorderBuffer) decomposeHangul(r rune) {
+	r -= hangulBase
+	x := r % jamoTCount
+	r /= jamoTCount
+	rb.appendRune(jamoLBase + r/jamoVCount)
+	rb.appendRune(jamoVBase + r%jamoVCount)
+	if x != 0 {
+		rb.appendRune(jamoTBase + x)
+	}
+}
+
+// combineHangul algorithmically combines Jamo character components into Hangul.
+// See https://unicode.org/reports/tr15/#Hangul for details on combining Hangul.
+func (rb *reorderBuffer) combineHangul(s, i, k int) {
+	b := rb.rune[:]
+	bn := rb.nrune
+	for ; i < bn; i++ {
+		cccB := b[k-1].ccc
+		cccC := b[i].ccc
+		if cccB == 0 {
+			s = k - 1
+		}
+		if s != k-1 && cccB >= cccC {
+			// b[i] is blocked by greater-equal cccX below it
+			b[k] = b[i]
+			k++
+		} else {
+			l := rb.runeAt(s) // also used to compare to hangulBase
+			v := rb.runeAt(i) // also used to compare to jamoT
+			switch {
+			case jamoLBase <= l && l < jamoLEnd &&
+				jamoVBase <= v && v < jamoVEnd:
+				// 11xx plus 116x to LV
+				rb.assignRune(s, hangulBase+
+					(l-jamoLBase)*jamoVTCount+(v-jamoVBase)*jamoTCount)
+			case hangulBase <= l && l < hangulEnd &&
+				jamoTBase < v && v < jamoTEnd &&
+				((l-hangulBase)%jamoTCount) == 0:
+				// ACxx plus 11Ax to LVT
+				rb.assignRune(s, l+v-jamoTBase)
+			default:
+				b[k] = b[i]
+				k++
+			}
+		}
+	}
+	rb.nrune = k
+}
+
+// compose recombines the runes in the buffer.
+// It should only be used to recompose a single segment, as it will not
+// handle alternations between Hangul and non-Hangul characters correctly.
+func (rb *reorderBuffer) compose() {
+	// Lazily load the map used by the combine func below, but do
+	// it outside of the loop.
+	recompMapOnce.Do(buildRecompMap)
+
+	// UAX #15, section X5 , including Corrigendum #5
+	// "In any character sequence beginning with starter S, a character C is
+	//  blocked from S if and only if there is some character B between S
+	//  and C, and either B is a starter or it has the same or higher
+	//  combining class as C."
+	bn := rb.nrune
+	if bn == 0 {
+		return
+	}
+	k := 1
+	b := rb.rune[:]
+	for s, i := 0, 1; i < bn; i++ {
+		if isJamoVT(rb.bytesAt(i)) {
+			// Redo from start in Hangul mode. Necessary to support
+			// U+320E..U+321E in NFKC mode.
+			rb.combineHangul(s, i, k)
+			return
+		}
+		ii := b[i]
+		// We can only use combineForward as a filter if we later
+		// get the info for the combined character. This is more
+		// expensive than using the filter. Using combinesBackward()
+		// is safe.
+		if ii.combinesBackward() {
+			cccB := b[k-1].ccc
+			cccC := ii.ccc
+			blocked := false // b[i] blocked by starter or greater or equal CCC?
+			if cccB == 0 {
+				s = k - 1
+			} else {
+				blocked = s != k-1 && cccB >= cccC
+			}
+			if !blocked {
+				combined := combine(rb.runeAt(s), rb.runeAt(i))
+				if combined != 0 {
+					rb.assignRune(s, combined)
+					continue
+				}
+			}
+		}
+		b[k] = b[i]
+		k++
+	}
+	rb.nrune = k
+}
-- 
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