49 lines
1.3 KiB
JavaScript
49 lines
1.3 KiB
JavaScript
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/**
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* multiple ocurrences of:
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* - alphabetical letter, underscore or dash, or
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* - non-ascii character, or
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* - escaped character
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* @type {RegExp}
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*/
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var rIdentifier =
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/(?:[A-Za-z0-9_-]|[^\0-\237]|\\(?:[^A-Fa-f0-9]|[A-Fa-f0-9]{1,6} ?))+/;
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/**
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* backslash followed by a non-hexadecimal letter or
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* a 1 to 6 digit hexadecimal number followed by an optional white space
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* @type {RegExp}
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*/
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var rEscapedCharacter = /\\([^A-Fa-f0-9]|[A-Fa-f0-9]{1,6} ?)/g;
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/**
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* Unescapes a single character
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* @param {string} escapedCharacter escaped character starting with a backslash
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* @return {string} unescaped character
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*/
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function unescapeCharacter(escapedCharacter) {
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var escapeValue = escapedCharacter.substr(1);
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var numberValue = parseInt(escapeValue, 16);
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if (isNaN(numberValue)) {
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return escapeValue;
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}
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return String.fromCharCode(numberValue);
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}
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/**
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* Unescapes all escaped characters in the given identifier
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* @param {string} identifier identifier with possible escaped characters
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* @return {string} unescaped identifier
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*/
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function unescapeIdentifier(identifier) {
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return identifier.replace(rEscapedCharacter, unescapeCharacter);
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}
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module.exports = {
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rIdentifier: rIdentifier,
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rEscapedCharacter: rEscapedCharacter,
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unescapeIdentifier: unescapeIdentifier,
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unescapeCharacter: unescapeCharacter
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};
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