how faster is it when I avoid using DO
do performance

  the price of DO
At 10:08 23.03.99 -0800, Terry Schussler wrote on the pros and cons (mainly) 
of using DO:

>Performance costs for using DO:

>-- Welcome to Director --
>doTest (executed three successive times)
>-- 54
>-- 50
>-- 52
>callTest (executed three successive times)
>-- 15
>-- 15
>-- 15

The ratio of this performance costs differed when I tested it with dfw 6.02, 
NT4, pII 300Mhz (1:2 instead of 1:3), but the tendency is the same. I definately
agree with Terry's advice to use alternatives whereever it is suitable. Thanks 
for the fine examples. 

However, I don't think the speed of executing the called handler is different. 
I think Terry's test shows a difference in the time needed to find the handler 
that should be executed.

I extended that test script a bit in order to compare the performance costs 
when executing different handlers (and setting the number of iterations, 
since - look yourself)

testem "dummy",100000
-- "do: 706"
-- "call: 337"

testem "stringTest",100
-- "do: 200"
-- "call: 199"

So, it appears that the performance gain that can be reached by using call is 
substantial  (50%) with a very short handler but not very impressive (0,5%) 
with a slow routine.

-- movie script "test"

on testem cmd,times
  dotest cmd,times
  callTest cmd,times

on doTest cmd,times
  repeat with loopCounter = 1 to times
    do cmd
  end repeat
  put "do:" && the timer
end doTest

on callTest cmd,times
  repeat with loopCounter = 1 to times
    call symbol(cmd), (script "test")
  end repeat
  put "call:" && the timer
end callTest

on dummy

on stringTest
  replaceChar the scripttext of member "test","e","x"  

on replaceChar str, oldChar, newChar
  -- replaces all occurences of oldChar in str with newChar
  -- ok for use in small input, it would be slow for large text
  repeat while str contains oldChar
    put newChar into char (offset (oldChar, str)) of str
  end repeat
  return str

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