JavaScript: Create regular expression string of input text to create search string match

script.js

var makeComp = (function(){
    var accents = {
            a: 'àáâãäåæ',
            c: 'ç',
            e: 'èéêëæ',
            i: 'ìíîï',
            n: 'ñ',
            o: 'òóôõöø',
            s: 'ß',
            u: 'ùúûü',
            y: 'ÿ'
        },
        chars = /[aceinosuy]/g;

    return function makeComp(input) {
        return input.replace(chars, function(c){
            return '[' + c + accents[c] + ']';
        });
    };
}());