Deleting lines within a 'repeat for each' loop

[Martin Steer]

Hello There,

Just a quick question to everyone here.

I've been trying to remove filenames (lines) from the string that the 
'files' function returns. The basic algorithm I've been using is below, 
but I think I've found a problem in the 'repeat for each chunkType' 
control structure in Rev.

Here's a little piece of code I was using to test. I've taken the 
filename checking out of the loop because that's not the problem. Just 
put this in a button's script and step through it using the variable 
watcher...

-----
on mouseUp

   put ".ds_store" & return & "Help File 1.xml" & return & "Help File 
3.xml" into fileList

   put 1 into i

   breakpoint
   repeat for each line currLine in fileList
     delete line i of fileList
     add 1 to i
   end repeat

end mouseUp
-----

The first iteration, the currLine variable gets ".ds_store", and then 
it deletes line 1. All is okay.

The second iteration, the currLine variable gets the sting "1.xml"... 
not "Help File 1.xml" as I assumed.

I tried removing the spaces in the file name thinking that may be 
stuffing up the chunks, but the second iteration results in currLine 
being set to the string "xml"

If you comment out the line that deletes the line from fileList, the 
repeat loop works fine.

I know the algorithm is flawed i.e. when you delete line 1, increment i 
to 2, then iterate again and delete line 2 it's actually deleting the 
original line 3. This is my buggy test script :) That bug doesn't 
matter though if each 'repeat' iteration the chunkType isn't correctly 
being evaluated. Originally, the deletion of a line occurs when a line 
matches the extension string at the end of the line (can't use 
'contains' so I've been using matchText and regular expressions.)

So, my questions are these:

1) Regardless of weather there's an easier way to remove lines from a 
string that don't match a pattern, is there something wrong with the 
way the 'repeat for each' control structure evaluates chunks when you 
manipulate the string it's repeating 'with'?

2) Is there an easier way to remove filenames from a list that don't 
have specific file extensions?

Oh, I've tried in Rev 2.0.2 and 2.1 and I'm running on Mac OS X 10.2.6

Thanks for reading this far :)

- Marty Steer
martin at pixelmedia.com.au