var A = ['A', 'B', 'C', 'A', 'B', 'B', 'A'],
    B = ['C', 'B', 'A', 'B', 'A', 'C'];

var editScript = diff(A, B);
// editScript = {
//     deletions: [0, 1, 5],
//     insertions: [1, 5],
// }

setCode: function(code, diff) {
    // Clear
    this.el.update("");

        // Create copies of the edit script
    var insertions = diff.insertions.slice(0),
        deletions = diff.deletions.slice(0),

        // Obtain reference to HTML templates
        lineTpl = Ext.ux.CodeViewer.lineTpl,
        emptyLineTpl = Ext.ux.CodeViewer.emptyLineTpl,

        // Create a "pre" tag to hold the code
        pre = this.el.createChild({tag: 'pre'}),

        // Normalize line-breaks in the code
        code = code.replace(/\r\n?/g, '\n'),

        // Split code into discrete lines
        lines = code.split('\n'),

        // Cursors/flags for walking the edit script
        sideAIndex = 0,
        sideBIndex = 0,
        sideAChangeIndex = deletions.shift(),
        sideBChangeIndex = insertions.shift(),
        prevWasModified = false;

    // Loop over each line
    for (var i = 0, n = lines.length; i<n; i++) {
        // Create the HTML for the line, including highlighting
        var el = lineTpl.append(pre, [i+1, this.highlightLine(lines)]);

        // By default we want to move both cursors forward
        var advanceA = true,
            advanceB = true;

        // If both cursors indicate a change, consider it to be a modification
        if (sideAIndex === sideAChangeIndex && sideBIndex === sideBChangeIndex) {
            Ext.fly(el).addClass('ux-codeViewer-modified');

            // Get next changes
            sideAChangeIndex = deletions.shift();
            sideBChangeIndex = insertions.shift();

            // Set modified flag so that following lines
            // are marked accordingly
            prevWasModified = true;
        }
        else {
            // Different logic for side A vs side B
            // For instance, an insert means an empty line on side A
            // and highlighting on side B
            if (this.sideA) {
                // If there was a deletion
                if (sideAIndex === sideAChangeIndex) {
                    // Either highlight as deleted or modified depending
                    // on the previous line
                    Ext.fly(el).addClass(prevWasModified ? 'ux-codeViewer-modified' : 'ux-codeViewer-deleted');

                    // Get next change
                    sideAChangeIndex = deletions.shift();

                    // Don't advance B cursor
                    advanceB = false;
                }
                else {
                    // If there were insertions, generate empty lines
                    while (sideBIndex === sideBChangeIndex) {
                        // Insert empty line
                        emptyLineTpl.insertBefore(el);

                        // Get next change
                        sideBChangeIndex = insertions.shift();

                        // Keep advancing as long as there was an insertion
                        sideBIndex++;
                    }
                }
            }
            // Side B
            else {
                //  If there was an insertation
                if (sideBIndex == sideBChangeIndex) {
                    // Either highlight as inserted or modified depending
                    // on the previous line
                    Ext.fly(el).addClass(prevWasModified ? 'ux-codeViewer-modified' : 'ux-codeViewer-inserted');

                    // Get next change
                    sideBChangeIndex = insertions.shift();

                    // Don't advance A cursor
                    advanceA = false;
                }
                else {
                    // If there were deletions, generate empty lines
                    while (sideAIndex === sideAChangeIndex) {
                        // Insert empty line
                        emptyLineTpl.insertBefore(el);

                        // Get next change
                        sideAChangeIndex = deletions.shift();

                        // Keep advancing as long as there was a deletion
                        sideAIndex++;
                    }
                }
            }

            // Reset modified flag
            prevWasModified = false;
        }

        // Advance cursors
        if (advanceA) { sideAIndex++; }
        if (advanceB) { sideBIndex++; }
    }
}