lib/jaconv.js
function toKatakana(s) {
        var res = '';
        for (var i = 0; i < s.length; i += 1) {
            var cd = s.charCodeAt(i);
            res += (minHira <= cd && cd <= maxHira) ?
                String.fromCharCode(cd - minHira + minKata) : s.charAt(i);
        }
        return res;
    }
function toKatakana(s) {
        var res = '';
        for (var i = 0; i < s.length; i += 1) {
            var cd = s.charCodeAt(i);
            res += (minHira <= cd && cd <= maxHira) ?
                String.fromCharCode(cd - minHira + minKata) : s.charAt(i);
        }
        return res;
    }
全角ひらがなを全角カタカナに変換します。