1
0
Fork 0
mirror of https://github.com/Luzifer/vault-otp-ui.git synced 2024-11-14 02:52:45 +00:00
vault-otp-ui/vendor/github.com/tdewolff/parse/js/lex.go
Knut Ahlers a483fab651
Vendor dependencies
Signed-off-by: Knut Ahlers <knut@ahlers.me>
2017-06-14 21:26:35 +02:00

540 lines
12 KiB
Go

// Package js is an ECMAScript5.1 lexer following the specifications at http://www.ecma-international.org/ecma-262/5.1/.
package js
import (
"io"
"strconv"
"unicode"
"github.com/tdewolff/buffer"
)
var identifierStart = []*unicode.RangeTable{unicode.Lu, unicode.Ll, unicode.Lt, unicode.Lm, unicode.Lo, unicode.Nl, unicode.Other_ID_Start}
var identifierContinue = []*unicode.RangeTable{unicode.Lu, unicode.Ll, unicode.Lt, unicode.Lm, unicode.Lo, unicode.Nl, unicode.Mn, unicode.Mc, unicode.Nd, unicode.Pc, unicode.Other_ID_Continue}
////////////////////////////////////////////////////////////////
// TokenType determines the type of token, eg. a number or a semicolon.
type TokenType uint32
// TokenType values.
const (
ErrorToken TokenType = iota // extra token when errors occur
UnknownToken // extra token when no token can be matched
WhitespaceToken // space \t \v \f
LineTerminatorToken // \r \n \r\n
CommentToken
IdentifierToken
PunctuatorToken /* { } ( ) [ ] . ; , < > <= >= == != === !== + - * % ++ -- << >>
>>> & | ^ ! ~ && || ? : = += -= *= %= <<= >>= >>>= &= |= ^= / /= >= */
NumericToken
StringToken
RegexpToken
TemplateToken
)
// String returns the string representation of a TokenType.
func (tt TokenType) String() string {
switch tt {
case ErrorToken:
return "Error"
case UnknownToken:
return "Unknown"
case WhitespaceToken:
return "Whitespace"
case LineTerminatorToken:
return "LineTerminator"
case CommentToken:
return "Comment"
case IdentifierToken:
return "Identifier"
case PunctuatorToken:
return "Punctuator"
case NumericToken:
return "Numeric"
case StringToken:
return "String"
case RegexpToken:
return "Regexp"
case TemplateToken:
return "Template"
}
return "Invalid(" + strconv.Itoa(int(tt)) + ")"
}
////////////////////////////////////////////////////////////////
// Lexer is the state for the lexer.
type Lexer struct {
r *buffer.Lexer
regexpState bool
templateState bool
}
// NewLexer returns a new Lexer for a given io.Reader.
func NewLexer(r io.Reader) *Lexer {
return &Lexer{
r: buffer.NewLexer(r),
}
}
// Err returns the error encountered during lexing, this is often io.EOF but also other errors can be returned.
func (l *Lexer) Err() error {
return l.r.Err()
}
// Free frees up bytes of length n from previously shifted tokens.
func (l *Lexer) Free(n int) {
l.r.Free(n)
}
// Next returns the next Token. It returns ErrorToken when an error was encountered. Using Err() one can retrieve the error message.
func (l *Lexer) Next() (TokenType, []byte) {
tt := UnknownToken
c := l.r.Peek(0)
switch c {
case '(', ')', '[', ']', '{', '}', ';', ',', '~', '?', ':':
if c == '}' && l.templateState && l.consumeTemplateToken() {
tt = TemplateToken
} else {
l.r.Move(1)
tt = PunctuatorToken
}
case '<', '>', '=', '!', '+', '-', '*', '%', '&', '|', '^':
if l.consumeLongPunctuatorToken() {
tt = PunctuatorToken
}
case '/':
if l.consumeCommentToken() {
return CommentToken, l.r.Shift()
} else if l.regexpState && l.consumeRegexpToken() {
tt = RegexpToken
} else if l.consumeLongPunctuatorToken() {
tt = PunctuatorToken
}
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.':
if l.consumeNumericToken() {
tt = NumericToken
} else if c == '.' {
l.r.Move(1)
tt = PunctuatorToken
}
case '\'', '"':
if l.consumeStringToken() {
tt = StringToken
}
case ' ', '\t', '\v', '\f':
l.r.Move(1)
for l.consumeWhitespace() {
}
return WhitespaceToken, l.r.Shift()
case '\n', '\r':
l.r.Move(1)
for l.consumeLineTerminator() {
}
tt = LineTerminatorToken
case '`':
l.templateState = true
if l.consumeTemplateToken() {
tt = TemplateToken
}
default:
if l.consumeIdentifierToken() {
tt = IdentifierToken
} else if c >= 0xC0 {
if l.consumeWhitespace() {
for l.consumeWhitespace() {
}
return WhitespaceToken, l.r.Shift()
} else if l.consumeLineTerminator() {
for l.consumeLineTerminator() {
}
tt = LineTerminatorToken
}
} else if l.Err() != nil {
return ErrorToken, nil
}
}
// differentiate between divisor and regexp state, because the '/' character is ambiguous!
// ErrorToken, WhitespaceToken and CommentToken are already returned
if tt == LineTerminatorToken || tt == PunctuatorToken && regexpStateByte[c] {
l.regexpState = true
} else {
l.regexpState = false
}
if tt == UnknownToken {
_, n := l.r.PeekRune(0)
l.r.Move(n)
}
return tt, l.r.Shift()
}
////////////////////////////////////////////////////////////////
/*
The following functions follow the specifications at http://www.ecma-international.org/ecma-262/5.1/
*/
func (l *Lexer) consumeWhitespace() bool {
c := l.r.Peek(0)
if c == ' ' || c == '\t' || c == '\v' || c == '\f' {
l.r.Move(1)
return true
} else if c >= 0xC0 {
if r, n := l.r.PeekRune(0); r == '\u00A0' || r == '\uFEFF' || unicode.Is(unicode.Zs, r) {
l.r.Move(n)
return true
}
}
return false
}
func (l *Lexer) consumeLineTerminator() bool {
c := l.r.Peek(0)
if c == '\n' {
l.r.Move(1)
return true
} else if c == '\r' {
if l.r.Peek(1) == '\n' {
l.r.Move(2)
} else {
l.r.Move(1)
}
return true
} else if c >= 0xC0 {
if r, n := l.r.PeekRune(0); r == '\u2028' || r == '\u2029' {
l.r.Move(n)
return true
}
}
return false
}
func (l *Lexer) consumeDigit() bool {
if c := l.r.Peek(0); c >= '0' && c <= '9' {
l.r.Move(1)
return true
}
return false
}
func (l *Lexer) consumeHexDigit() bool {
if c := l.r.Peek(0); (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F') {
l.r.Move(1)
return true
}
return false
}
func (l *Lexer) consumeBinaryDigit() bool {
if c := l.r.Peek(0); c == '0' || c == '1' {
l.r.Move(1)
return true
}
return false
}
func (l *Lexer) consumeOctalDigit() bool {
if c := l.r.Peek(0); c >= '0' && c <= '7' {
l.r.Move(1)
return true
}
return false
}
func (l *Lexer) consumeUnicodeEscape() bool {
if l.r.Peek(0) != '\\' || l.r.Peek(1) != 'u' {
return false
}
mark := l.r.Pos()
l.r.Move(2)
if c := l.r.Peek(0); c == '{' {
l.r.Move(1)
if l.consumeHexDigit() {
for l.consumeHexDigit() {
}
if c := l.r.Peek(0); c == '}' {
l.r.Move(1)
return true
}
}
l.r.Rewind(mark)
return false
} else if !l.consumeHexDigit() || !l.consumeHexDigit() || !l.consumeHexDigit() || !l.consumeHexDigit() {
l.r.Rewind(mark)
return false
}
return true
}
////////////////////////////////////////////////////////////////
func (l *Lexer) consumeCommentToken() bool {
if l.r.Peek(0) != '/' || l.r.Peek(1) != '/' && l.r.Peek(1) != '*' {
return false
}
if l.r.Peek(1) == '/' {
l.r.Move(2)
// single line
for {
c := l.r.Peek(0)
if c == '\r' || c == '\n' || c == 0 {
break
} else if c >= 0xC0 {
mark := l.r.Pos()
if r, _ := l.r.PeekRune(0); r == '\u2028' || r == '\u2029' {
l.r.Rewind(mark)
break
}
}
l.r.Move(1)
}
} else {
l.r.Move(2)
// multi line
for {
c := l.r.Peek(0)
if c == '*' && l.r.Peek(1) == '/' {
l.r.Move(2)
return true
} else if c == 0 {
break
}
l.r.Move(1)
}
}
return true
}
func (l *Lexer) consumeLongPunctuatorToken() bool {
c := l.r.Peek(0)
if c == '!' || c == '=' || c == '+' || c == '-' || c == '*' || c == '/' || c == '%' || c == '&' || c == '|' || c == '^' {
l.r.Move(1)
if l.r.Peek(0) == '=' {
l.r.Move(1)
if (c == '!' || c == '=') && l.r.Peek(0) == '=' {
l.r.Move(1)
}
} else if (c == '+' || c == '-' || c == '&' || c == '|') && l.r.Peek(0) == c {
l.r.Move(1)
} else if c == '=' && l.r.Peek(0) == '>' {
l.r.Move(1)
}
} else { // c == '<' || c == '>'
l.r.Move(1)
if l.r.Peek(0) == c {
l.r.Move(1)
if c == '>' && l.r.Peek(0) == '>' {
l.r.Move(1)
}
}
if l.r.Peek(0) == '=' {
l.r.Move(1)
}
}
return true
}
func (l *Lexer) consumeIdentifierToken() bool {
c := l.r.Peek(0)
if (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '$' || c == '_' {
l.r.Move(1)
} else if c >= 0xC0 {
if r, n := l.r.PeekRune(0); unicode.IsOneOf(identifierStart, r) {
l.r.Move(n)
} else {
return false
}
} else if !l.consumeUnicodeEscape() {
return false
}
for {
c := l.r.Peek(0)
if (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '$' || c == '_' {
l.r.Move(1)
} else if c >= 0xC0 {
if r, n := l.r.PeekRune(0); r == '\u200C' || r == '\u200D' || unicode.IsOneOf(identifierContinue, r) {
l.r.Move(n)
} else {
break
}
} else {
break
}
}
return true
}
func (l *Lexer) consumeNumericToken() bool {
// assume to be on 0 1 2 3 4 5 6 7 8 9 .
mark := l.r.Pos()
c := l.r.Peek(0)
if c == '0' {
l.r.Move(1)
if l.r.Peek(0) == 'x' || l.r.Peek(0) == 'X' {
l.r.Move(1)
if l.consumeHexDigit() {
for l.consumeHexDigit() {
}
} else {
l.r.Move(-1) // return just the zero
}
return true
} else if l.r.Peek(0) == 'b' || l.r.Peek(0) == 'B' {
l.r.Move(1)
if l.consumeBinaryDigit() {
for l.consumeBinaryDigit() {
}
} else {
l.r.Move(-1) // return just the zero
}
return true
} else if l.r.Peek(0) == 'o' || l.r.Peek(0) == 'O' {
l.r.Move(1)
if l.consumeOctalDigit() {
for l.consumeOctalDigit() {
}
} else {
l.r.Move(-1) // return just the zero
}
return true
}
} else if c != '.' {
for l.consumeDigit() {
}
}
if l.r.Peek(0) == '.' {
l.r.Move(1)
if l.consumeDigit() {
for l.consumeDigit() {
}
} else if c != '.' {
// . could belong to the next token
l.r.Move(-1)
return true
} else {
l.r.Rewind(mark)
return false
}
}
mark = l.r.Pos()
c = l.r.Peek(0)
if c == 'e' || c == 'E' {
l.r.Move(1)
c = l.r.Peek(0)
if c == '+' || c == '-' {
l.r.Move(1)
}
if !l.consumeDigit() {
// e could belong to the next token
l.r.Rewind(mark)
return true
}
for l.consumeDigit() {
}
}
return true
}
func (l *Lexer) consumeStringToken() bool {
// assume to be on ' or "
mark := l.r.Pos()
delim := l.r.Peek(0)
l.r.Move(1)
for {
c := l.r.Peek(0)
if c == delim {
l.r.Move(1)
break
} else if c == '\\' {
l.r.Move(1)
if !l.consumeLineTerminator() {
if c := l.r.Peek(0); c == delim || c == '\\' {
l.r.Move(1)
}
}
continue
} else if c == '\n' || c == '\r' {
l.r.Rewind(mark)
return false
} else if c >= 0xC0 {
if r, _ := l.r.PeekRune(0); r == '\u2028' || r == '\u2029' {
l.r.Rewind(mark)
return false
}
} else if c == 0 {
break
}
l.r.Move(1)
}
return true
}
func (l *Lexer) consumeRegexpToken() bool {
// assume to be on / and not /*
mark := l.r.Pos()
l.r.Move(1)
inClass := false
for {
c := l.r.Peek(0)
if !inClass && c == '/' {
l.r.Move(1)
break
} else if c == '[' {
inClass = true
} else if c == ']' {
inClass = false
} else if c == '\\' {
l.r.Move(1)
if l.consumeLineTerminator() {
l.r.Rewind(mark)
return false
}
} else if l.consumeLineTerminator() {
l.r.Rewind(mark)
return false
} else if c == 0 {
return true
}
l.r.Move(1)
}
// flags
for {
c := l.r.Peek(0)
if (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '$' || c == '_' {
l.r.Move(1)
} else if c >= 0xC0 {
if r, n := l.r.PeekRune(0); r == '\u200C' || r == '\u200D' || unicode.IsOneOf(identifierContinue, r) {
l.r.Move(n)
} else {
break
}
} else {
break
}
}
return true
}
func (l *Lexer) consumeTemplateToken() bool {
// assume to be on ` or } when already within template
mark := l.r.Pos()
l.r.Move(1)
for {
c := l.r.Peek(0)
if c == '`' {
l.templateState = false
l.r.Move(1)
return true
} else if c == '$' && l.r.Peek(1) == '{' {
l.r.Move(2)
return true
} else if c == 0 {
l.r.Rewind(mark)
return false
}
l.r.Move(1)
}
}