Potential Categorization algorithm for Porter Stemmer

categorization.js

function categorizeGroups(token) {
    var previous = null;
    var current = null;
    var string = "";
    for(var c in token) {
        var ch = token[c];
        var next = null;

        // Y is a special case, it is only a vowel if preceeded by a vowel.
        if(ch === "y") {
            if(previous.match(/[aeiou]/)) {
                next = "C";
            } else {
                next = "V";
            }
        } else if(ch.match(/[^aeiou]/)) {
            next = "C";
        } else {
            next = "V";
        }

        if(next != current) {
            current = next;
            string += current;
        }

        previous = ch;
    }
    return string;
}

// denote single consonants with a C and single vowels with a V
function categorizeChars(token) {
    var previous = null;
    var string = "";
    for(var c in token) {
        var ch = token[c];
        var next = null;

        // Y is a special case, it is only a vowel if preceeded by a vowel.
        if(ch === "y") {
            if(previous.match(/[aeiou]/)) {
                next = "C";
            } else {
                next = "V";
            }
        } else if(ch.match(/[^aeiou]/)) {
            next = "C";
        } else {
            next = "V";
        }

        string += next;
        previous = ch;
    }
    return string;
}