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gitea/vendor/github.com/blevesearch/snowballstem/env.go

390 lines
6.8 KiB
Go

package snowballstem
import (
"log"
"strings"
"unicode/utf8"
)
// Env represents the Snowball execution environment
type Env struct {
current string
Cursor int
Limit int
LimitBackward int
Bra int
Ket int
}
// NewEnv creates a new Snowball execution environment on the provided string
func NewEnv(val string) *Env {
return &Env{
current: val,
Cursor: 0,
Limit: len(val),
LimitBackward: 0,
Bra: 0,
Ket: len(val),
}
}
func (env *Env) Current() string {
return env.current
}
func (env *Env) SetCurrent(s string) {
env.current = s
env.Cursor = 0
env.Limit = len(s)
env.LimitBackward = 0
env.Bra = 0
env.Ket = len(s)
}
func (env *Env) ReplaceS(bra, ket int, s string) int32 {
adjustment := int32(len(s)) - (int32(ket) - int32(bra))
result, _ := splitAt(env.current, bra)
rsplit := ket
if ket < bra {
rsplit = bra
}
_, rhs := splitAt(env.current, rsplit)
result += s
result += rhs
newLim := int32(env.Limit) + adjustment
env.Limit = int(newLim)
if env.Cursor >= ket {
newCur := int32(env.Cursor) + adjustment
env.Cursor = int(newCur)
} else if env.Cursor > bra {
env.Cursor = bra
}
env.current = result
return adjustment
}
func (env *Env) EqS(s string) bool {
if env.Cursor >= env.Limit {
return false
}
if strings.HasPrefix(env.current[env.Cursor:], s) {
env.Cursor += len(s)
for !onCharBoundary(env.current, env.Cursor) {
env.Cursor++
}
return true
}
return false
}
func (env *Env) EqSB(s string) bool {
if int32(env.Cursor)-int32(env.LimitBackward) < int32(len(s)) {
return false
} else if !onCharBoundary(env.current, env.Cursor-len(s)) ||
!strings.HasPrefix(env.current[env.Cursor-len(s):], s) {
return false
} else {
env.Cursor -= len(s)
return true
}
}
func (env *Env) SliceFrom(s string) bool {
bra, ket := env.Bra, env.Ket
env.ReplaceS(bra, ket, s)
return true
}
func (env *Env) NextChar() {
env.Cursor++
for !onCharBoundary(env.current, env.Cursor) {
env.Cursor++
}
}
func (env *Env) PrevChar() {
env.Cursor--
for !onCharBoundary(env.current, env.Cursor) {
env.Cursor--
}
}
func (env *Env) ByteIndexForHop(delta int32) int32 {
if delta > 0 {
res := env.Cursor
for delta > 0 {
res++
delta--
for res <= len(env.current) && !onCharBoundary(env.current, res) {
res++
}
}
return int32(res)
} else if delta < 0 {
res := env.Cursor
for delta < 0 {
res--
delta++
for res >= 0 && !onCharBoundary(env.current, res) {
res--
}
}
return int32(res)
} else {
return int32(env.Cursor)
}
}
func (env *Env) InGrouping(chars []byte, min, max int32) bool {
if env.Cursor >= env.Limit {
return false
}
r, _ := utf8.DecodeRuneInString(env.current[env.Cursor:])
if r != utf8.RuneError {
if r > max || r < min {
return false
}
r -= min
if (chars[uint(r>>3)] & (0x1 << uint(r&0x7))) == 0 {
return false
}
env.NextChar()
return true
}
return false
}
func (env *Env) InGroupingB(chars []byte, min, max int32) bool {
if env.Cursor <= env.LimitBackward {
return false
}
env.PrevChar()
r, _ := utf8.DecodeRuneInString(env.current[env.Cursor:])
if r != utf8.RuneError {
env.NextChar()
if r > max || r < min {
return false
}
r -= min
if (chars[uint(r>>3)] & (0x1 << uint(r&0x7))) == 0 {
return false
}
env.PrevChar()
return true
}
return false
}
func (env *Env) OutGrouping(chars []byte, min, max int32) bool {
if env.Cursor >= env.Limit {
return false
}
r, _ := utf8.DecodeRuneInString(env.current[env.Cursor:])
if r != utf8.RuneError {
if r > max || r < min {
env.NextChar()
return true
}
r -= min
if (chars[uint(r>>3)] & (0x1 << uint(r&0x7))) == 0 {
env.NextChar()
return true
}
}
return false
}
func (env *Env) OutGroupingB(chars []byte, min, max int32) bool {
if env.Cursor <= env.LimitBackward {
return false
}
env.PrevChar()
r, _ := utf8.DecodeRuneInString(env.current[env.Cursor:])
if r != utf8.RuneError {
env.NextChar()
if r > max || r < min {
env.PrevChar()
return true
}
r -= min
if (chars[uint(r>>3)] & (0x1 << uint(r&0x7))) == 0 {
env.PrevChar()
return true
}
}
return false
}
func (env *Env) SliceDel() bool {
return env.SliceFrom("")
}
func (env *Env) Insert(bra, ket int, s string) {
adjustment := env.ReplaceS(bra, ket, s)
if bra <= env.Bra {
env.Bra = int(int32(env.Bra) + adjustment)
}
if bra <= env.Ket {
env.Ket = int(int32(env.Ket) + adjustment)
}
}
func (env *Env) SliceTo() string {
return env.current[env.Bra:env.Ket]
}
func (env *Env) FindAmong(amongs []*Among, ctx interface{}) int32 {
var i int32
j := int32(len(amongs))
c := env.Cursor
l := env.Limit
var commonI, commonJ int
firstKeyInspected := false
for {
k := i + ((j - i) >> 1)
var diff int32
common := min(commonI, commonJ)
w := amongs[k]
for lvar := common; lvar < len(w.Str); lvar++ {
if c+common == l {
diff--
break
}
diff = int32(env.current[c+common]) - int32(w.Str[lvar])
if diff != 0 {
break
}
common++
}
if diff < 0 {
j = k
commonJ = common
} else {
i = k
commonI = common
}
if j-i <= 1 {
if i > 0 {
break
}
if j == i {
break
}
if firstKeyInspected {
break
}
firstKeyInspected = true
}
}
for {
w := amongs[i]
if commonI >= len(w.Str) {
env.Cursor = c + len(w.Str)
if w.F != nil {
res := w.F(env, ctx)
env.Cursor = c + len(w.Str)
if res {
return w.B
}
} else {
return w.B
}
}
i = w.A
if i < 0 {
return 0
}
}
}
func (env *Env) FindAmongB(amongs []*Among, ctx interface{}) int32 {
var i int32
j := int32(len(amongs))
c := env.Cursor
lb := env.LimitBackward
var commonI, commonJ int
firstKeyInspected := false
for {
k := i + ((j - i) >> 1)
diff := int32(0)
common := min(commonI, commonJ)
w := amongs[k]
for lvar := len(w.Str) - int(common) - 1; lvar >= 0; lvar-- {
if c-common == lb {
diff--
break
}
diff = int32(env.current[c-common-1]) - int32(w.Str[lvar])
if diff != 0 {
break
}
// Count up commons. But not one character but the byte width of that char
common++
}
if diff < 0 {
j = k
commonJ = common
} else {
i = k
commonI = common
}
if j-i <= 1 {
if i > 0 {
break
}
if j == i {
break
}
if firstKeyInspected {
break
}
firstKeyInspected = true
}
}
for {
w := amongs[i]
if commonI >= len(w.Str) {
env.Cursor = c - len(w.Str)
if w.F != nil {
res := w.F(env, ctx)
env.Cursor = c - len(w.Str)
if res {
return w.B
}
} else {
return w.B
}
}
i = w.A
if i < 0 {
return 0
}
}
}
func (env *Env) Debug(count, lineNumber int) {
log.Printf("snowball debug, count: %d, line: %d", count, lineNumber)
}
func (env *Env) Clone() *Env {
clone := *env
return &clone
}
func (env *Env) AssignTo() string {
return env.Current()
}