TokenIterator = function(session, initialRow, initialColumn) {
    this.$session = session;
    this.$row = initialRow;
    this.$rowTokens = session.getTokens(initialRow);

    var token = session.getTokenAt(initialRow, initialColumn);
    this.$tokenIndex = token ? token.index : -1;
}
new TokenIterator(session, initialRow, initialColumn)
- session (EditSession): The session to associate with
- initialRow (Number): The row to start the tokenizing at
- initialColumn (Number): The column to start the tokenizing at

Creates a new token iterator object. The inital token index is set to the provided row and column coordinates.