Incrementing indexes or putting empty into an array

[David Bovill]

For a long time I've incremente indexes with a line_Add or line_Insert
function - now that I'm optimising things for release I've started doing the
following:

repeat for each line someLine in someText
  process someLine
  put empty into lineArray [someLine]
end repeat
put keys (lineArray) into unsortedindex

It's nice and convenient to write, but I wonder how fast it is...