// Copyright 2014 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.
// +build ignore
// This program generates the trie for casing operations. The Unicode casing
// algorithm requires the lookup of various properties and mappings for each
// rune. The table generated by this generator combines several of the most
// frequently used of these into a single trie so that they can be accessed
// with a single lookup.
package main
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"log"
"reflect"
"strconv"
"strings"
"unicode"
"golang.org/x/text/internal/gen"
"golang.org/x/text/internal/triegen"
"golang.org/x/text/internal/ucd"
"golang.org/x/text/unicode/norm"
)
func main() {
gen.Init()
genTables()
genTablesTest()
gen.Repackage("gen_trieval.go", "trieval.go", "cases")
}
// runeInfo contains all information for a rune that we care about for casing
// operations.
type runeInfo struct {
Rune rune
entry info // trie value for this rune.
CaseMode info
// Simple case mappings.
Simple [1 + maxCaseMode][]rune
// Special casing
HasSpecial bool
Conditional bool
Special [1 + maxCaseMode][]rune
// Folding
FoldSimple rune
FoldSpecial rune
FoldFull []rune
// TODO: FC_NFKC, or equivalent data.
// Properties
SoftDotted bool
CaseIgnorable bool
Cased bool
DecomposeGreek bool
BreakType string
BreakCat breakCategory
// We care mostly about 0, Above, and IotaSubscript.
CCC byte
}
type breakCategory int
const (
breakBreak breakCategory = iota
breakLetter
breakMid
)
// mapping returns the case mapping for the given case type.
func (r *runeInfo) mapping(c info) string {
if r.HasSpecial {
return string(r.Special[c])
}
if len(r.Simple[c]) != 0 {
return string(r.Simple[c])
}
return string(r.Rune)
}
func parse(file string, f func(p *ucd.Parser)) {
ucd.Parse(gen.OpenUCDFile(file), f)
}
func parseUCD() []runeInfo {
chars := make([]runeInfo, unicode.MaxRune)
get := func(r rune) *runeInfo {
c := &chars[r]
c.Rune = r
return c
}
parse("UnicodeData.txt", func(p *ucd.Parser) {
ri := get(p.Rune(0))
ri.CCC = byte(p.Int(ucd.CanonicalCombiningClass))
ri.Simple[cLower] = p.Runes(ucd.SimpleLowercaseMapping)
ri.Simple[cUpper] = p.Runes(ucd.SimpleUppercaseMapping)
ri.Simple[cTitle] = p.Runes(ucd.SimpleTitlecaseMapping)
if p.String(ucd.GeneralCategory) == "Lt" {
ri.CaseMode = cTitle
}
})
// <code>; <property>
parse("PropList.txt", func(p *ucd.Parser) {
if p.String(1) == "Soft_Dotted" {
chars[p.Rune(0)].SoftDotted = true
}
})
// <code>; <word break type>
parse("DerivedCoreProperties.txt", func(p *ucd.Parser) {
ri := get(p.Rune(0))
switch p.String(1) {
case "Case_Ignorable":
ri.CaseIgnorable = true
case "Cased":
ri.Cased = true
case "Lowercase":
ri.CaseMode = cLower
case "Uppercase":
ri.CaseMode = cUpper
}
})
// <code>; <lower> ; <title> ; <upper> ; (<condition_list> ;)?
parse("SpecialCasing.txt", func(p *ucd.Parser) {
// We drop all conditional special casing and deal with them manually in
// the language-specific case mappers. Rune 0x03A3 is the only one with
// a conditional formatting that is not language-specific. However,
// dealing with this letter is tricky, especially in a streaming
// context, so we deal with it in the Caser for Greek specifically.
ri := get(p.Rune(0))
if p.String(4) == "" {
ri.HasSpecial = true
ri.Special[cLower] = p.Runes(1)
ri.Special[cTitle] = p.Runes(2)
ri.Special[cUpper] = p.Runes(3)
} else {
ri.Conditional = true
}
})
// TODO: Use text breaking according to UAX #29.
// <code>; <word break type>
parse("auxiliary/WordBreakProperty.txt", func(p *ucd.Parser) {
ri := get(p.Rune(0))
ri.BreakType = p.String(1)
// We collapse the word breaking properties onto the categories we need.
switch p.String(1) { // TODO: officially we need to canonicalize.
case "MidLetter", "MidNumLet", "Single_Quote":
ri.BreakCat = breakMid
if !ri.CaseIgnorable {
// finalSigma relies on the fact that all breakMid runes are
// also a Case_Ignorable. Revisit this code when this changes.
log.Fatalf("Rune %U, which has a break category mid, is not a case ignorable", ri)
}
case "ALetter", "Hebrew_Letter", "Numeric", "Extend", "ExtendNumLet", "Format", "ZWJ":
ri.BreakCat = breakLetter
}
})
// <code>; <type>; <mapping>
parse("CaseFolding.txt", func(p *ucd.Parser) {
ri := get(p.Rune(0))
switch p.String(1) {
case "C":
ri.FoldSimple = p.Rune(2)
ri.FoldFull = p.Runes(2)
case "S":
ri.FoldSimple = p.Rune(2)
case "T":
ri.FoldSpecial = p.Rune(2)
case "F":
ri.FoldFull = p.Runes(2)
default:
log.Fatalf("%U: unknown type: %s", p.Rune(0), p.String(1))
}
})
return chars
}
func genTables() {
chars := parseUCD()
verifyProperties(chars)
t := triegen.NewTrie("case")
for i := range chars {
c := &chars[i]
makeEntry(c)
t.Insert(rune(i), uint64(c.entry))
}
w := gen.NewCodeWriter()
defer w.WriteVersionedGoFile("tables.go", "cases")
gen.WriteUnicodeVersion(w)
// TODO: write CLDR version after adding a mechanism to detect that the
// tables on which the manually created locale-sensitive casing code is
// based hasn't changed.
w.WriteVar("xorData", string(xorData))
w.WriteVar("exceptions", string(exceptionData))
sz, err := t.Gen(w, triegen.Compact(&sparseCompacter{}))
if err != nil {
log.Fatal(err)
}
w.Size += sz
}
func makeEntry(ri *runeInfo) {
if ri.CaseIgnorable {
if ri.Cased {
ri.entry = cIgnorableCased
} else {
ri.entry = cIgnorableUncased
}
} else {
ri.entry = ri.CaseMode
}
// TODO: handle soft-dotted.
ccc := cccOther
switch ri.CCC {
case 0: // Not_Reordered
ccc = cccZero
case above: // Above
ccc = cccAbove
}
switch ri.BreakCat {
case breakBreak:
ccc = cccBreak
case breakMid:
ri.entry |= isMidBit
}
ri.entry |= ccc
if ri.CaseMode == cUncased {
return
}
// Need to do something special.
if ri.CaseMode == cTitle || ri.HasSpecial || ri.mapping(cTitle) != ri.mapping(cUpper) {
makeException(ri)
return
}
if f := string(ri.FoldFull); len(f) > 0 && f != ri.mapping(cUpper) && f != ri.mapping(cLower) {
makeException(ri)
return
}
// Rune is either lowercase or uppercase.
orig := string(ri.Rune)
mapped := ""
if ri.CaseMode == cUpper {
mapped = ri.mapping(cLower)
} else {
mapped = ri.mapping(cUpper)
}
if len(orig) != len(mapped) {
makeException(ri)
return
}
if string(ri.FoldFull) == ri.mapping(cUpper) {
ri.entry |= inverseFoldBit
}
n := len(orig)
// Create per-byte XOR mask.
var b []byte
for i := 0; i < n; i++ {
b = append(b, orig[i]^mapped[i])
}
// Remove leading 0 bytes, but keep at least one byte.
for ; len(b) > 1 && b[0] == 0; b = b[1:] {
}
if len(b) == 1 && b[0]&0xc0 == 0 {
ri.entry |= info(b[0]) << xorShift
return
}
key := string(b)
x, ok := xorCache[key]
if !ok {
xorData = append(xorData, 0) // for detecting start of sequence
xorData = append(xorData, b...)
x = len(xorData) - 1
xorCache[key] = x
}
ri.entry |= info(x<<xorShift) | xorIndexBit
}
var xorCache = map[string]int{}
// xorData contains byte-wise XOR data for the least significant bytes of a
// UTF-8 encoded rune. An index points to the last byte. The sequence starts
// with a zero terminator.
var xorData = []byte{}
// See the comments in gen_trieval.go re "the exceptions slice".
var exceptionData = []byte{0}
// makeException encodes case mappings that cannot be expressed in a simple
// XOR diff.
func makeException(ri *runeInfo) {
ccc := ri.entry & cccMask
// Set exception bit and retain case type.
ri.entry &= 0x0007
ri.entry |= exceptionBit
if len(exceptionData) >= 1<<numExceptionBits {
log.Fatalf("%U:exceptionData too large %x > %d bits", ri.Rune, len(exceptionData), numExceptionBits)
}
// Set the offset in the exceptionData array.
ri.entry |= info(len(exceptionData) << exceptionShift)
orig := string(ri.Rune)
tc := ri.mapping(cTitle)
uc := ri.mapping(cUpper)
lc := ri.mapping(cLower)
ff := string(ri.FoldFull)
// addString sets the length of a string and adds it to the expansions array.
addString := func(s string, b *byte) {
if len(s) == 0 {
// Zero-length mappings exist, but only for conditional casing,
// which we are representing outside of this table.
log.Fatalf("%U: has zero-length mapping.", ri.Rune)
}
*b <<= 3
if s != orig {
n := len(s)
if n > 7 {
log.Fatalf("%U: mapping larger than 7 (%d)", ri.Rune, n)
}
*b |= byte(n)
exceptionData = append(exceptionData, s...)
}
}
// byte 0:
exceptionData = append(exceptionData, byte(ccc)|byte(len(ff)))
// byte 1:
p := len(exceptionData)
exceptionData = append(exceptionData, 0)
if len(ff) > 7 { // May be zero-length.
log.Fatalf("%U: fold string larger than 7 (%d)", ri.Rune, len(ff))
}
exceptionData = append(exceptionData, ff...)
ct := ri.CaseMode
if ct != cLower {
addString(lc, &exceptionData[p])
}
if ct != cUpper {
addString(uc, &exceptionData[p])
}
if ct != cTitle {
// If title is the same as upper, we set it to the original string so
// that it will be marked as not present. This implies title case is
// the same as upper case.
if tc == uc {
tc = orig
}
addString(tc, &exceptionData[p])
}
}
// sparseCompacter is a trie value block Compacter. There are many cases where
// successive runes alternate between lower- and upper-case. This Compacter
// exploits this by adding a special case type where the case value is obtained
// from or-ing it with the least-significant bit of the rune, creating large
// ranges of equal case values that compress well.
type sparseCompacter struct {
sparseBlocks [][]uint16
sparseOffsets []uint16
sparseCount int
}
// makeSparse returns the number of elements that compact block would contain
// as well as the modified values.
func makeSparse(vals []uint64) ([]uint16, int) {
// Copy the values.
values := make([]uint16, len(vals))
for i, v := range vals {
values[i] = uint16(v)
}
alt := func(i int, v uint16) uint16 {
if cm := info(v & fullCasedMask); cm == cUpper || cm == cLower {
// Convert cLower or cUpper to cXORCase value, which has the form 11x.
xor := v
xor &^= 1
xor |= uint16(i&1) ^ (v & 1)
xor |= 0x4
return xor
}
return v
}
var count int
var previous uint16
for i, v := range values {
if v != 0 {
// Try if the unmodified value is equal to the previous.
if v == previous {
continue
}
// Try if the xor-ed value is equal to the previous value.
a := alt(i, v)
if a == previous {
values[i] = a
continue
}
// This is a new value.
count++
// Use the xor-ed value if it will be identical to the next value.
if p := i + 1; p < len(values) && alt(p, values[p]) == a {
values[i] = a
v = a
}
}
previous = v
}
return values, count
}
func (s *sparseCompacter) Size(v []uint64) (int, bool) {
_, n := makeSparse(v)
// We limit using this method to having 16 entries.
if n > 16 {
return 0, false
}
return 2 + int(reflect.TypeOf(valueRange{}).Size())*n, true
}
func (s *sparseCompacter) Store(v []uint64) uint32 {
h := uint32(len(s.sparseOffsets))
values, sz := makeSparse(v)
s.sparseBlocks = append(s.sparseBlocks, values)
s.sparseOffsets = append(s.sparseOffsets, uint16(s.sparseCount))
s.sparseCount += sz
return h
}
func (s *sparseCompacter) Handler() string {
// The sparse global variable and its lookup method is defined in gen_trieval.go.
return "sparse.lookup"
}
func (s *sparseCompacter) Print(w io.Writer) (retErr error) {
p := func(format string, args ...interface{}) {
_, err := fmt.Fprintf(w, format, args...)
if retErr == nil && err != nil {
retErr = err
}
}
ls := len(s.sparseBlocks)
if ls == len(s.sparseOffsets) {
s.sparseOffsets = append(s.sparseOffsets, uint16(s.sparseCount))
}
p("// sparseOffsets: %d entries, %d bytes\n", ls+1, (ls+1)*2)
p("var sparseOffsets = %#v\n\n", s.sparseOffsets)
ns := s.sparseCount
p("// sparseValues: %d entries, %d bytes\n", ns, ns*4)
p("var sparseValues = [%d]valueRange {", ns)
for i, values := range s.sparseBlocks {
p("\n// Block %#x, offset %#x", i, s.sparseOffsets[i])
var v uint16
for i, nv := range values {
if nv != v {
if v != 0 {
p(",hi:%#02x},", 0x80+i-1)
}
if nv != 0 {
p("\n{value:%#04x,lo:%#02x", nv, 0x80+i)
}
}
v = nv
}
if v != 0 {
p(",hi:%#02x},", 0x80+len(values)-1)
}
}
p("\n}\n\n")
return
}
// verifyProperties that properties of the runes that are relied upon in the
// implementation. Each property is marked with an identifier that is referred
// to in the places where it is used.
func verifyProperties(chars []runeInfo) {
for i, c := range chars {
r := rune(i)
// Rune properties.
// A.1: modifier never changes on lowercase. [ltLower]
if c.CCC > 0 && unicode.ToLower(r) != r {
log.Fatalf("%U: non-starter changes when lowercased", r)
}
// A.2: properties of decompositions starting with I or J. [ltLower]
d := norm.NFD.PropertiesString(string(r)).Decomposition()
if len(d) > 0 {
if d[0] == 'I' || d[0] == 'J' {
// A.2.1: we expect at least an ASCII character and a modifier.
if len(d) < 3 {
log.Fatalf("%U: length of decomposition was %d; want >= 3", r, len(d))
}
// All subsequent runes are modifiers and all have the same CCC.
runes := []rune(string(d[1:]))
ccc := chars[runes[0]].CCC
for _, mr := range runes[1:] {
mc := chars[mr]
// A.2.2: all modifiers have a CCC of Above or less.
if ccc == 0 || ccc > above {
log.Fatalf("%U: CCC of successive rune (%U) was %d; want (0,230]", r, mr, ccc)
}
// A.2.3: a sequence of modifiers all have the same CCC.
if mc.CCC != ccc {
log.Fatalf("%U: CCC of follow-up modifier (%U) was %d; want %d", r, mr, mc.CCC, ccc)
}
// A.2.4: for each trailing r, r in [0x300, 0x311] <=> CCC == Above.
if (ccc == above) != (0x300 <= mr && mr <= 0x311) {
log.Fatalf("%U: modifier %U in [U+0300, U+0311] != ccc(%U) == 230", r, mr, mr)
}
if i += len(string(mr)); i >= len(d) {
break
}
}
}
}
// A.3: no U+0307 in decomposition of Soft-Dotted rune. [ltUpper]
if unicode.Is(unicode.Soft_Dotted, r) && strings.Contains(string(d), "\u0307") {
log.Fatalf("%U: decomposition of soft-dotted rune may not contain U+0307", r)
}
// A.4: only rune U+0345 may be of CCC Iota_Subscript. [elUpper]
if c.CCC == iotaSubscript && r != 0x0345 {
log.Fatalf("%U: only rune U+0345 may have CCC Iota_Subscript", r)
}
// A.5: soft-dotted runes do not have exceptions.
if c.SoftDotted && c.entry&exceptionBit != 0 {
log.Fatalf("%U: soft-dotted has exception", r)
}
// A.6: Greek decomposition. [elUpper]
if unicode.Is(unicode.Greek, r) {
if b := norm.NFD.PropertiesString(string(r)).Decomposition(); b != nil {
runes := []rune(string(b))
// A.6.1: If a Greek rune decomposes and the first rune of the
// decomposition is greater than U+00FF, the rune is always
// great and not a modifier.
if f := runes[0]; unicode.IsMark(f) || f > 0xFF && !unicode.Is(unicode.Greek, f) {
log.Fatalf("%U: expected first rune of Greek decomposition to be letter, found %U", r, f)
}
// A.6.2: Any follow-up rune in a Greek decomposition is a
// modifier of which the first should be gobbled in
// decomposition.
for _, m := range runes[1:] {
switch m {
case 0x0313, 0x0314, 0x0301, 0x0300, 0x0306, 0x0342, 0x0308, 0x0304, 0x345:
default:
log.Fatalf("%U: modifier %U is outside of expected Greek modifier set", r, m)
}
}
}
}
// Breaking properties.
// B.1: all runes with CCC > 0 are of break type Extend.
if c.CCC > 0 && c.BreakType != "Extend" {
log.Fatalf("%U: CCC == %d, but got break type %s; want Extend", r, c.CCC, c.BreakType)
}
// B.2: all cased runes with c.CCC == 0 are of break type ALetter.
if c.CCC == 0 && c.Cased && c.BreakType != "ALetter" {
log.Fatalf("%U: cased, but got break type %s; want ALetter", r, c.BreakType)
}
// B.3: letter category.
if c.CCC == 0 && c.BreakCat != breakBreak && !c.CaseIgnorable {
if c.BreakCat != breakLetter {
log.Fatalf("%U: check for letter break type gave %d; want %d", r, c.BreakCat, breakLetter)
}
}
}
}
func genTablesTest() {
w := &bytes.Buffer{}
fmt.Fprintln(w, "var (")
printProperties(w, "DerivedCoreProperties.txt", "Case_Ignorable", verifyIgnore)
// We discard the output as we know we have perfect functions. We run them
// just to verify the properties are correct.
n := printProperties(ioutil.Discard, "DerivedCoreProperties.txt", "Cased", verifyCased)
n += printProperties(ioutil.Discard, "DerivedCoreProperties.txt", "Lowercase", verifyLower)
n += printProperties(ioutil.Discard, "DerivedCoreProperties.txt", "Uppercase", verifyUpper)
if n > 0 {
log.Fatalf("One of the discarded properties does not have a perfect filter.")
}
// <code>; <lower> ; <title> ; <upper> ; (<condition_list> ;)?
fmt.Fprintln(w, "\tspecial = map[rune]struct{ toLower, toTitle, toUpper string }{")
parse("SpecialCasing.txt", func(p *ucd.Parser) {
// Skip conditional entries.
if p.String(4) != "" {
return
}
r := p.Rune(0)
fmt.Fprintf(w, "\t\t0x%04x: {%q, %q, %q},\n",
r, string(p.Runes(1)), string(p.Runes(2)), string(p.Runes(3)))
})
fmt.Fprint(w, "\t}\n\n")
// <code>; <type>; <runes>
table := map[rune]struct{ simple, full, special string }{}
parse("CaseFolding.txt", func(p *ucd.Parser) {
r := p.Rune(0)
t := p.String(1)
v := string(p.Runes(2))
if t != "T" && v == string(unicode.ToLower(r)) {
return
}
x := table[r]
switch t {
case "C":
x.full = v
x.simple = v
case "S":
x.simple = v
case "F":
x.full = v
case "T":
x.special = v
}
table[r] = x
})
fmt.Fprintln(w, "\tfoldMap = map[rune]struct{ simple, full, special string }{")
for r := rune(0); r < 0x10FFFF; r++ {
x, ok := table[r]
if !ok {
continue
}
fmt.Fprintf(w, "\t\t0x%04x: {%q, %q, %q},\n", r, x.simple, x.full, x.special)
}
fmt.Fprint(w, "\t}\n\n")
// Break property
notBreak := map[rune]bool{}
parse("auxiliary/WordBreakProperty.txt", func(p *ucd.Parser) {
switch p.String(1) {
case "Extend", "Format", "MidLetter", "MidNumLet", "Single_Quote",
"ALetter", "Hebrew_Letter", "Numeric", "ExtendNumLet", "ZWJ":
notBreak[p.Rune(0)] = true
}
})
fmt.Fprintln(w, "\tbreakProp = []struct{ lo, hi rune }{")
inBreak := false
for r := rune(0); r <= lastRuneForTesting; r++ {
if isBreak := !notBreak[r]; isBreak != inBreak {
if isBreak {
fmt.Fprintf(w, "\t\t{0x%x, ", r)
} else {
fmt.Fprintf(w, "0x%x},\n", r-1)
}
inBreak = isBreak
}
}
if inBreak {
fmt.Fprintf(w, "0x%x},\n", lastRuneForTesting)
}
fmt.Fprint(w, "\t}\n\n")
// Word break test
// Filter out all samples that do not contain cased characters.
cased := map[rune]bool{}
parse("DerivedCoreProperties.txt", func(p *ucd.Parser) {
if p.String(1) == "Cased" {
cased[p.Rune(0)] = true
}
})
fmt.Fprintln(w, "\tbreakTest = []string{")
parse("auxiliary/WordBreakTest.txt", func(p *ucd.Parser) {
c := strings.Split(p.String(0), " ")
const sep = '|'
numCased := 0
test := ""
for ; len(c) >= 2; c = c[2:] {
if c[0] == "รท" && test != "" {
test += string(sep)
}
i, err := strconv.ParseUint(c[1], 16, 32)
r := rune(i)
if err != nil {
log.Fatalf("Invalid rune %q.", c[1])
}
if r == sep {
log.Fatalf("Separator %q not allowed in test data. Pick another one.", sep)
}
if cased[r] {
numCased++
}
test += string(r)
}
if numCased > 1 {
fmt.Fprintf(w, "\t\t%q,\n", test)
}
})
fmt.Fprintln(w, "\t}")
fmt.Fprintln(w, ")")
gen.WriteVersionedGoFile("tables_test.go", "cases", w.Bytes())
}
// These functions are just used for verification that their definition have not
// changed in the Unicode Standard.
func verifyCased(r rune) bool {
return verifyLower(r) || verifyUpper(r) || unicode.IsTitle(r)
}
func verifyLower(r rune) bool {
return unicode.IsLower(r) || unicode.Is(unicode.Other_Lowercase, r)
}
func verifyUpper(r rune) bool {
return unicode.IsUpper(r) || unicode.Is(unicode.Other_Uppercase, r)
}
// verifyIgnore is an approximation of the Case_Ignorable property using the
// core unicode package. It is used to reduce the size of the test data.
func verifyIgnore(r rune) bool {
props := []*unicode.RangeTable{
unicode.Mn,
unicode.Me,
unicode.Cf,
unicode.Lm,
unicode.Sk,
}
for _, p := range props {
if unicode.Is(p, r) {
return true
}
}
return false
}
// printProperties prints tables of rune properties from the given UCD file.
// A filter func f can be given to exclude certain values. A rune r will have
// the indicated property if it is in the generated table or if f(r).
func printProperties(w io.Writer, file, property string, f func(r rune) bool) int {
verify := map[rune]bool{}
n := 0
varNameParts := strings.Split(property, "_")
varNameParts[0] = strings.ToLower(varNameParts[0])
fmt.Fprintf(w, "\t%s = map[rune]bool{\n", strings.Join(varNameParts, ""))
parse(file, func(p *ucd.Parser) {
if p.String(1) == property {
r := p.Rune(0)
verify[r] = true
if !f(r) {
n++
fmt.Fprintf(w, "\t\t0x%.4x: true,\n", r)
}
}
})
fmt.Fprint(w, "\t}\n\n")
// Verify that f is correct, that is, it represents a subset of the property.
for r := rune(0); r <= lastRuneForTesting; r++ {
if !verify[r] && f(r) {
log.Fatalf("Incorrect filter func for property %q.", property)
}
}
return n
}
// The newCaseTrie, sparseValues and sparseOffsets definitions below are
// placeholders referred to by gen_trieval.go. The real definitions are
// generated by this program and written to tables.go.
func newCaseTrie(int) int { return 0 }
var (
sparseValues [0]valueRange
sparseOffsets [0]uint16
)
