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package js_ast
import (
"strings"
"unicode"
"unicode/utf8"
)
func IsIdentifier(text string) bool {
if len(text) == 0 {
return false
}
for i, codePoint := range text {
if i == 0 {
if !IsIdentifierStart(codePoint) {
return false
}
} else {
if !IsIdentifierContinue(codePoint) {
return false
}
}
}
return true
}
func IsIdentifierES5AndESNext(text string) bool {
if len(text) == 0 {
return false
}
for i, codePoint := range text {
if i == 0 {
if !IsIdentifierStartES5AndESNext(codePoint) {
return false
}
} else {
if !IsIdentifierContinueES5AndESNext(codePoint) {
return false
}
}
}
return true
}
func ForceValidIdentifier(prefix string, text string) string {
sb := strings.Builder{}
// Private identifiers must be prefixed by "#"
if prefix != "" {
sb.WriteString(prefix)
}
// Identifier start
c, width := utf8.DecodeRuneInString(text)
text = text[width:]
if IsIdentifierStart(c) {
sb.WriteRune(c)
} else {
sb.WriteRune('_')
}
// Identifier continue
for text != "" {
c, width := utf8.DecodeRuneInString(text)
text = text[width:]
if IsIdentifierContinue(c) {
sb.WriteRune(c)
} else {
sb.WriteRune('_')
}
}
return sb.String()
}
// This does "IsIdentifier(UTF16ToString(text))" without any allocations
func IsIdentifierUTF16(text []uint16) bool {
n := len(text)
if n == 0 {
return false
}
for i := 0; i < n; i++ {
isStart := i == 0
r1 := rune(text[i])
if r1 >= 0xD800 && r1 <= 0xDBFF && i+1 < n {
if r2 := rune(text[i+1]); r2 >= 0xDC00 && r2 <= 0xDFFF {
r1 = (r1 << 10) + r2 + (0x10000 - (0xD800 << 10) - 0xDC00)
i++
}
}
if isStart {
if !IsIdentifierStart(r1) {
return false
}
} else {
if !IsIdentifierContinue(r1) {
return false
}
}
}
return true
}
// This does "IsIdentifierES5AndESNext(UTF16ToString(text))" without any allocations
func IsIdentifierES5AndESNextUTF16(text []uint16) bool {
n := len(text)
if n == 0 {
return false
}
for i := 0; i < n; i++ {
isStart := i == 0
r1 := rune(text[i])
if r1 >= 0xD800 && r1 <= 0xDBFF && i+1 < n {
if r2 := rune(text[i+1]); r2 >= 0xDC00 && r2 <= 0xDFFF {
r1 = (r1 << 10) + r2 + (0x10000 - (0xD800 << 10) - 0xDC00)
i++
}
}
if isStart {
if !IsIdentifierStartES5AndESNext(r1) {
return false
}
} else {
if !IsIdentifierContinueES5AndESNext(r1) {
return false
}
}
}
return true
}
func IsIdentifierStart(codePoint rune) bool {
switch codePoint {
case '_', '$',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z':
return true
}
// All ASCII identifier start code points are listed above
if codePoint < 0x7F {
return false
}
return unicode.Is(idStartES5OrESNext, codePoint)
}
func IsIdentifierContinue(codePoint rune) bool {
switch codePoint {
case '_', '$', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z':
return true
}
// All ASCII identifier start code points are listed above
if codePoint < 0x7F {
return false
}
// ZWNJ and ZWJ are allowed in identifiers
if codePoint == 0x200C || codePoint == 0x200D {
return true
}
return unicode.Is(idContinueES5OrESNext, codePoint)
}
func IsIdentifierStartES5AndESNext(codePoint rune) bool {
switch codePoint {
case '_', '$',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z':
return true
}
// All ASCII identifier start code points are listed above
if codePoint < 0x7F {
return false
}
return unicode.Is(idStartES5AndESNext, codePoint)
}
func IsIdentifierContinueES5AndESNext(codePoint rune) bool {
switch codePoint {
case '_', '$', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z':
return true
}
// All ASCII identifier start code points are listed above
if codePoint < 0x7F {
return false
}
// ZWNJ and ZWJ are allowed in identifiers
if codePoint == 0x200C || codePoint == 0x200D {
return true
}
return unicode.Is(idContinueES5AndESNext, codePoint)
}
// See the "White Space Code Points" table in the ECMAScript standard
func IsWhitespace(codePoint rune) bool {
switch codePoint {
case
'\u0009', // character tabulation
'\u000B', // line tabulation
'\u000C', // form feed
'\u0020', // space
'\u00A0', // no-break space
// Unicode "Space_Separator" code points
'\u1680', // ogham space mark
'\u2000', // en quad
'\u2001', // em quad
'\u2002', // en space
'\u2003', // em space
'\u2004', // three-per-em space
'\u2005', // four-per-em space
'\u2006', // six-per-em space
'\u2007', // figure space
'\u2008', // punctuation space
'\u2009', // thin space
'\u200A', // hair space
'\u202F', // narrow no-break space
'\u205F', // medium mathematical space
'\u3000', // ideographic space
'\uFEFF': // zero width non-breaking space
return true
default:
return false
}
}
|
