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Escape sequences in our identifiers have already been handled

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This commit is contained in:
Tim Schaub
2013-06-07 12:05:45 -06:00
parent 0844df8cc2
commit 4d62cea700
1 changed files with 12 additions and 126 deletions
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138
src/ol/expression/lexer.js
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@@ -29,7 +29,6 @@ ol.expression.Char = {
LOWER_A: 97,
LOWER_E: 101,
LOWER_F: 102,
LOWER_U: 117,
LOWER_X: 120,
LOWER_Z: 122,
MINUS: 45,
@@ -374,129 +373,6 @@ ol.expression.Lexer.prototype.getCurrentCharCode_ = function() {
};
/**
* Get an identifier that includes escape sequences.
*
* @return {string} The identifier.
* @private
*/
ol.expression.Lexer.prototype.getEscapedIdentifier_ = function() {
var code = this.getCurrentCharCode_();
var id = String.fromCharCode(code);
this.increment_(1);
// the \u sequence denotes an escaped character
if (code === ol.expression.Char.BACKSLASH) {
if (this.getCurrentCharCode_() !== ol.expression.Char.LOWER_U) {
throw new Error('Unexpected token at index ' + this.index_ +
': ' + this.getCurrentChar_());
}
this.increment_(1);
code = this.scanEscapeSequence_(ol.expression.Char.LOWER_U);
if (!code || code === ol.expression.Char.BACKSLASH ||
!this.isIdentifierStart_(code)) {
throw new Error('Unexpected token at index ' + this.index_ +
': ' + this.getCurrentChar_());
}
id = String.fromCharCode(code);
}
while (this.index_ < this.length_) {
code = this.getCurrentCharCode_();
if (!this.isIdentifierPart_(code)) {
break;
}
this.increment_(1);
id += String.fromCharCode(code);
// the \u sequence denotes an escaped character
if (code === ol.expression.Char.BACKSLASH) {
if (this.getCurrentCharCode_() !== ol.expression.Char.LOWER_U) {
throw new Error('Unexpected token at index ' + this.index_ +
': ' + this.getCurrentChar_());
}
id = id.substr(0, id.length - 1);
this.increment_(1);
code = this.scanEscapeSequence_(ol.expression.Char.LOWER_U);
if (!code || code === ol.expression.Char.BACKSLASH ||
!this.isIdentifierStart_(code)) {
throw new Error('Unexpected token at index ' + this.index_ +
': ' + this.getCurrentChar_());
}
id += String.fromCharCode(code);
}
}
return id;
};
/**
* Get an identifier. This assumes we've encountered an identifier that doesn't
* start with an escape sequence. If an escape sequence is encountered during
* the scan, we switch to the `getEscapedIdentifier_` method.
*
* @return {string} The identifier.
* @private
*/
ol.expression.Lexer.prototype.getIdentifier_ = function() {
goog.asserts.assert(
this.getCurrentCharCode_() !== ol.expression.Char.BACKSLASH,
'Must not be called with first char a backslash');
var start = this.index_;
this.increment_(1);
var code;
while (this.index_ < this.length_) {
code = this.getCurrentCharCode_();
if (code === ol.expression.Char.BACKSLASH) {
// reset cursor and start over scanning escaped identifier
this.index_ = start;
return this.getEscapedIdentifier_();
}
if (this.isIdentifierPart_(code)) {
this.increment_(1);
} else {
break;
}
}
return this.source_.slice(start, this.index_);
};
/**
* Scan an escape sequence of characters prefixed by the given character
* code. This works for both unicode escape sequences (e.g. \u0123) and
* hex escape sequences (e.g. \x12).
* http://www.ecma-international.org/ecma-262/5.1/#sec-7.8.4
*
* @param {number} prefix The character code of the escape prefix.
* @return {number} The unicode of the string resulting from the escape
* sequence. For invalid escape sequences, 0 is returned.
* @private
*/
ol.expression.Lexer.prototype.scanEscapeSequence_ = function(prefix) {
var code = 0;
var len = (prefix === ol.expression.Char.LOWER_U) ? 4 : 2;
var ch;
for (var i = 0; i < len; ++i) {
if (this.index_ < this.length_ &&
this.isHexDigit_(this.getCurrentCharCode_())) {
ch = this.getCurrentChar_();
code = (code * 16) + parseInt(ch, 16);
this.increment_(1);
} else {
return 0;
}
}
return code;
};
/**
* Scan hex literal as numeric token.
*
@@ -546,8 +422,18 @@ ol.expression.Lexer.prototype.scanIdentifier_ = function() {
goog.asserts.assert(this.isIdentifierStart_(code),
'Must be called with a valid identifier');
var id = (code === ol.expression.Char.BACKSLASH) ?
this.getEscapedIdentifier_() : this.getIdentifier_();
var start = this.index_;
this.increment_(1);
while (this.index_ < this.length_) {
code = this.getCurrentCharCode_();
if (this.isIdentifierPart_(code)) {
this.increment_(1);
} else {
break;
}
}
var id = this.source_.slice(start, this.index_);
var type;
if (id.length === 1) {