str-escape.js

// A simple string escape function.
define(function() { return function str_escape(s) {
        if (s.toSource) {
            // If available, abuse `toSource()` to properly quote a string
            // value.
            return s.toSource().slice(12,-2);
        }
        // Erg, use hand-coded version.
        var quotes = '"';
        if (s.indexOf('"') !== -1 && s.indexOf("'") === -1) {
            quotes = "'";
        }

        var table = {};
        table["\n"] = "n";
        table["\r"] = "r";
        table["\f"] = "f";
        table["\b"] = "b";
        table["\t"] = "t";
        table["\\"] = "\\";
        table[quotes] = quotes;

        var result = "", i=0;
        while (i < s.length) {
            var c = s.charAt(i);
            if (table.hasOwnProperty(c)) {
                result += "\\" + table[c];
            } else if (c < ' ' || c > '~') {
                // XXX allow some accented UTF-8 characters (printable ones)?
                var cc = c.charCodeAt(0).toString(16);
                while (cc.length < 4) {
                    cc = "0" + cc;
                }
                result += "\\u" + cc;
            } else {
                result += c;
            }
            i += 1;
        }
        return quotes + result + quotes;
    };
});