Hyphenate long words

hyphenateLongWords.js

/**
 * Add a soft hypen (­) to any words in the string longer than the given character length
 * 
 * @param  {string} str             Input string
 * @param  {int}    maxWordSize     Max character length of a word
 * @param  {int}    minFragmentSize [optional] Minimum chars to leave after a hyphen
 * @return {string}
 */
var hyphenateLongWords = function (str, maxWordSize, minFragmentSize) {
    // TODO: Find out char codes of word break chars
    // TODO: Cope with html entities in input string
    var l = str.length,
        i,
        j,
        // Chars client will break at - including those forced by allowBreaks function above
        wordBreaks = ['/', '\\', '.', '?', '!', ' ', '-', '(', '@'],
        hyphenated = '',
        wordSize,
        fragmentSize,
        smallestFragment,
        fragmentDiff,
        numHyphens;

    if (!maxWordSize) {
        return str;
    }

    if (minFragmentSize == null) {
        minFragmentSize = Math.floor(maxWordSize/2);
    }

    // Loop through chars
    for (i=0; i<l; i+=1) {
        // Find next word ending
        for (j=i; j<l; j+=1) {
            if ($.inArray(str[j], wordBreaks) !== -1) {
                break;
            }
        }

        wordSize = j-i;

        // If too long split into fragments seperated by &shy;
        if (wordSize > maxWordSize) {
            numHyphens = Math.floor(wordSize / maxWordSize);
            fragmentSize = maxWordSize;
            smallestFragment = wordSize % maxWordSize;

            // If final fragment is too small reduce size of previous fragments to compensate
            if (smallestFragment !== 0 && smallestFragment < minFragmentSize) {
                fragmentDiff = minFragmentSize - smallestFragment;
                fragmentSize -= Math.ceil(fragmentDiff / numHyphens);
            }

            while (i < j) {
                if (numHyphens) {
                    hyphenated += str.substr(i, fragmentSize) + '&shy';
                    i += fragmentSize;
                    numHyphens -= 1;
                } else {
                    hyphenated += str.substring(i, j+1);
                    i = j;
                }
            }
        } else {
            hyphenated += str.substring(i, j+1);
        }

        i = j;
    }

    return hyphenated;
}