gistfile1.hx

function orderedMerge(a:Array<Int>, b:Array<Int>){
    var result = new Array<Int>();
    
    var ai = 0, bi = 0;
    while(ai < a.length || bi < b.length){
        var nextA:Null<Int> = ai < a.length ? a[ai] : null;
        var nextB:Null<Int> = bi < b.length ? b[bi] : null;

        if((nextA < nextB && nextA != null) || nextB == null){
            result.push(nextA);
            ai++;
        }else{
            result.push(nextB);
            bi++;
        }
    }

    return result;
}