lib/xregexp/unicode-base.js
function charCode(chr) {
        var esc = /^\\[xu](.+)/.exec(chr);
        return esc ?
            dec(esc[1]) :
            chr.charCodeAt(chr.charAt(0) === '\\' ? 1 : 0);
    }
function charCode(chr) {
        var esc = /^\\[xu](.+)/.exec(chr);
        return esc ?
            dec(esc[1]) :
            chr.charCodeAt(chr.charAt(0) === '\\' ? 1 : 0);
    }
function charCode ( chr ) { var esc = / ^\\[xu](.+) / . exec ( chr ) ; return esc ? dec ( esc [ 1 ] ) : chr . charCodeAt ( chr . charAt ( 0 ) === '\\' ? 1 : 0 ) ; }
Gets the decimal code of a literal code unit, \xHH, \uHHHH, or a backslash-escaped literal
Gets the decimal code of a literal code unit \ xHH \ uHHHH or a backslash - escaped literal