Gammon Forum

function find (name)
  dim names, walks 'Storing your location names and speed walks.
  names = split(world.getvariable("???"),",") 'What ever ones you use.
  walks = split(world.getvariable("???"),",")
  w
  fd = false
  st = 0
  en = ubound(record)
  do until fd or st = en
    cr = st + int((en-st)/2)
    if names(cr) > name then
      en = cr
    else if names(cr) < name then
      st = cr
    else
      fd = True
    end if
    if le = en and lst = st then 'Otherwise it goes forever if no match exists.
      exit do
    else
      lst = st
      le = en
    end if
  loop
  if fd then
    find = walks(cr)
  else
    find = "Unknown!" 'Check for this in the calling script (since sending it is pointless.) ;)
  end if
end function

function find (name) {
  var temp = new StringTokenizer(world.getvariable("names"),","); //Replace 'names' with the variable you are using for them.
  var names = new arraylist()
  while (temp.hasMoreTokens()) {
    names.add(temp.nextToken());
  }
  temp = new StringTokenizer(world.getvariable("walks"),","); //Replace 'walks' with the variable you are using to store them.
  var walks = new arraylist()
  while (temp.hasMoreTokens()) {
    walks.add(temp.nextToken());
  }
  var fd = false;
  var st = 0;
  var en = names.size();
  var cr;
  var le = 0;
  var lst = 0;
  do {
    cr = st + int((en-st)/2);
    if (names(cr) > name)
      en = cr;
    else {
      if (names(cr) < name)
        st = cr;
      else
        fd = True;
    }
    if (le = en and lst = st) //Otherwise it goes forever if no match exists.
      break; //'exit do' would be better and more specific, but apparently they wan't it to be confusing. lol
             // Not to mention there being some question in my mind as to how you force an exit of a sub or
             // other nested object if you can't specifically tell it what you are 'break'ing out of. :p
    else {
      lst = st;
      le = en;
    }
  while not(fd) and st <> en}
  if (fd)
    find = walks(cr);
  else
    find = "Unknown!"; //'Check for this in the calling script (since sending it is pointless.) ;)
}

Now.. As I said I don't know javascript hardly at all and don't claim that this can or will work right. Prehaps if Nick or
someone gave it a look over first, but I have no idea if it work work as written. Specifically... The use of 'Arraylist' and
StringTokenizer. These 'should' collectively work like 'split' in VB, but I really can't say for certain. Most of this is
pulled a bit at a time from a Java manual and may work differently or not at all under Javascript.

Anyway, good luck and hopefully someone will look this over for you, instead of glossing over it like they seem to have done
with the VB version (which had several errors).

function find (name) {
  var names_string, names_array
  var walks_string, walks_array
  var found, start, end, current
  var last_start, last_end

  // get names from variable, as a comma-delimited string  
  names_string = world.getvariable("names");
  // convert into an array
  names_array = names_string.split (",");

  // get walks from variable, as a comma-delimited string  
  walks_string = world.getvariable("walks");
  // convert into an array
  walks_array = walks_string.split (",");

  found = false;  // not found yet
  start = 0;      // start at left
  end = names_array.length;  // end at right
  last_start = 0;  // for checking end of loop
  last_end = 0;    // ditto

  // loop until found
  while (!found || start != end)
    {
    // find half-way point
    current = start + ( (end - start) >> 1);
 
    // if name is > this position, it must be to the left
    if (names_array [current] > name)
      end = current;
    // if name is < this position, it must be to the right
    else if (names_array [current] < name)
      start = current;
    else
      {
      found = true;
      break;
      }

    // this check makes sure we don't loop indefinitely
    if (last_end == end && last_start == start)
      break;
    else
       {
       last_end = end;
       last_start = start;
       }

    }  // end of while loop


  if (found)
    return walks_array [current];

  return "Unknown!"; 

}	// end of function find