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otto/type_regexp.go
Robert Krimen 68943ba1e4 More (complex) RegExp => RE2 transforming and tests
The unescaping of that which does not need escaping
2012-10-20 23:32:30 -07:00

289 lines
6.8 KiB
Go

package otto
import (
"fmt"
"regexp"
"strings"
)
type _regExpObject struct {
RegularExpression *regexp.Regexp
Global bool
IgnoreCase bool
Multiline bool
Source string
LastIndex Value
}
func (runtime *_runtime) newRegExpObject(pattern string, flags string) *_object {
self := runtime.newObject()
self.Class = "RegExp"
global := false
ignoreCase := false
multiline := false
re2flags := ""
for _, rune := range flags {
switch rune {
case 'g':
if global {
panic(newError("SyntaxError: newRegExpObject: %s %s", pattern, flags))
}
global = true
case 'm':
if multiline {
panic(newError("SyntaxError: newRegExpObject: %s %s", pattern, flags))
}
multiline = true
case 'i':
if ignoreCase {
panic(newError("SyntaxError: newRegExpObject: %s %s", pattern, flags))
}
ignoreCase = true
re2flags += "i"
}
}
re2pattern := transformRegExp(pattern)
if len(re2flags) > 0 {
re2pattern = fmt.Sprintf("(?%s:%s)", re2flags, re2pattern)
}
self.RegExp = &_regExpObject{
RegularExpression: regexp.MustCompile(re2pattern),
Global: global,
IgnoreCase: ignoreCase,
Multiline: multiline,
Source: pattern,
LastIndex: toValue(0),
}
self._propertyStash = newRegExpStash(self.RegExp, self._propertyStash)
return self
}
func execRegExp(this *_object, target string) (match bool, result []int) {
lastIndex := toInteger(this.Get("lastIndex"))
index := lastIndex
global := toBoolean(this.Get("global"))
if !global {
index = 0
}
if 0 > index || index > int64(len(target)) {
} else {
result = this.RegExp.RegularExpression.FindStringSubmatchIndex(target[index:])
}
if result == nil {
this.WriteValue("lastIndex", toValue(0), true)
return // !match
}
match = true
endIndex := result[len(result)-1]
if global {
this.WriteValue("lastIndex", toValue(endIndex), true)
}
return // match
}
func execResultToArray(runtime *_runtime, target string, result []int) *_object {
captureCount := len(result) / 2
valueArray := make([]Value, captureCount)
for index := 0; index < captureCount; index++ {
offset := 2 * index
if result[offset] != -1 {
valueArray[index] = toValue(target[result[offset]:result[offset+1]])
} else {
valueArray[index] = UndefinedValue()
}
}
return runtime.newArray(valueArray)
}
// 0031,0032,0033,0034,0035,0036,0037,0038,0039 // 1 - 9
// 0043,0045,0046,0047,0048,0049,004A,004B,004C,004D,004E,004F
// 0050,0052,0054,0055,0056,0058,0059,005A
// 0063,0065,0067,0068,0069,006A,006B,006C,006D,006F
// 0070,0071,0075,0078,0079
// 0080,0081,0082,0083,0084,0085,0086,0087,0088,0089,008A,008B,008C,008D,008E,008F
// 0090,0091,0092,0093,0094,0095,0096,0097,0098,0099,009A,009B,009C,009D,009E,009F
// 00A0,00A1,00A2,00A3,00A4,00A5,00A6,00A7,00A8,00A9,00AA,00AB,00AC,00AD,00AE,00AF
// 00B0,00B1,00B2,00B3,00B4,00B5,00B6,00B7,00B8,00B9,00BA,00BB,00BC,00BD,00BE,00BF
// 00C0,00C1,00C2,00C3,00C4,00C5,00C6,00C7,00C8,00C9,00CA,00CB,00CC,00CD,00CE,00CF
// ...
// c = 63* c[A-Z]
// p = 70
// u = 75* u[:xdigit:]{4}
// x = 78* x[:xdigit:]{2}
//\x{0031}-\x{0039}
var transformRegExp_matchSlashU = regexp.MustCompile(`\\u([[:xdigit:]]{1,4})`)
var transformRegExp_unescape = regexp.MustCompile(strings.NewReplacer("\n", "", "\t", "", " ", "").Replace(`
(?:
\\(
[
\x{0043}\x{0045}-\x{004F}
\x{0050}\x{0052}\x{0054}-\x{0056}\x{0058}-\x{005A}
\x{0065}\x{0067}-\x{006D}\x{006F}
\x{0070}\x{0071}\x{0079}
\x{0080}-\x{FFFF}
]
)()
) |
(?:
\\(c)([^A-Z])
) |
(?:
\\(u)([^[:xdigit:]])
) |
(?:
\\(u)([:xdigit:][^[:xdigit:]])
) |
(?:
\\(u)([:xdigit:][:xdigit:][^[:xdigit:]])
) |
(?:
\\(u)([:xdigit:][:xdigit:][:xdigit:][^[:xdigit:]])
) |
(?:
\\(x)([^[:xdigit:]])
) |
(?:
\\(x)([:xdigit:][^[:xdigit:]])
)
`))
var transformRegExp_unescapeDollar = regexp.MustCompile(strings.NewReplacer("\n", "", "\t", "", " ", "").Replace(`
(?:
\\([cux])$
)
`))
// TODO Go "regexp" bug? Can't do: (?:)|(?:$)
func transformRegExp(ecmaRegExp string) (goRegExp string) {
tmp := []byte(ecmaRegExp)
tmp = transformRegExp_unescape.ReplaceAll(tmp, []byte(`$1$2`))
tmp = transformRegExp_unescapeDollar.ReplaceAll(tmp, []byte(`$1`))
tmp = transformRegExp_matchSlashU.ReplaceAll(tmp, []byte(`\x{$1}`))
return string(tmp)
}
func isValidRegExp(ecmaRegExp string) bool {
shibboleth := 0 // The shibboleth in this case is (?
// Since we're looking for (?! / (?=
inSet := false // In a bracketed set, e.g. [0-9]
escape := false
for _, chr := range ecmaRegExp {
if escape {
escape = false
shibboleth = 0
continue
}
if chr == '\\' {
escape = true
continue
}
if inSet {
if chr == ']' {
inSet = false
shibboleth = 0
}
continue
}
switch chr {
case '[':
inSet = true
continue
case '(':
shibboleth = 1
continue
case '?':
if shibboleth == 1 {
shibboleth = 2
}
continue
case '=', '!':
if shibboleth == 2 {
return false
}
}
shibboleth = 0
}
return true
}
// _regExpStash
type _regExpStash struct {
_regExpObject *_regExpObject
_stash
}
func newRegExpStash(_regExpObject *_regExpObject, stash _stash) *_regExpStash {
self := &_regExpStash{
_regExpObject,
stash,
}
return self
}
func (self *_regExpStash) CanRead(name string) bool {
switch name {
case "global", "ignoreCase", "multiline", "lastIndex", "source":
return true
}
return self._stash.CanRead(name)
}
func (self *_regExpStash) Read(name string) Value {
switch name {
case "global":
return toValue(self._regExpObject.Global)
case "ignoreCase":
return toValue(self._regExpObject.IgnoreCase)
case "multiline":
return toValue(self._regExpObject.Multiline)
case "lastIndex":
return self._regExpObject.LastIndex
case "source":
return toValue(self._regExpObject.Source)
}
return self._stash.Read(name)
}
func (self *_regExpStash) Write(name string, value Value) {
switch name {
case "global", "ignoreCase", "multiline", "source":
// TODO Is this good enough? Check DefineOwnProperty
panic(newTypeError())
case "lastIndex":
self._regExpObject.LastIndex = value
return
}
self._stash.Write(name, value)
}
func (self *_regExpStash) property(name string) *_property {
switch name {
case "global":
return &_property{Value: toValue(self._regExpObject.Global), Mode: 0} // -Write -Enumerate -Configure
case "ignoreCase":
return &_property{Value: toValue(self._regExpObject.IgnoreCase), Mode: 0} // -Write -Enumerate -Configure
case "multiline":
return &_property{Value: toValue(self._regExpObject.Multiline), Mode: 0} // -Write -Enumerate -Configure
case "lastIndex":
return &_property{Value: (self._regExpObject.LastIndex), Mode: propertyModeWrite} // +Write -Enumerate -Configure
case "source":
return &_property{Value: toValue(self._regExpObject.Source), Mode: 0} // -Write -Enumerate -Configure
}
return self._stash.property(name)
}
func (self *_regExpStash) Enumerate(each func(string)) {
// Skip global, ignoreCase, multiline, source, & lastIndex
self._stash.Enumerate(each)
}