Why is dispatch so fast?

Richard Gaskin ambassador at fourthworld.com
Tue Nov 12 04:06:29 CET 2013


Mark Wieder wrote:

> Saturday, November 9, 2013, 10:30:38 PM, Richard wrote:
>
>>> Why is the dispatch command so much faster than do, send, or call?
>
>> The main difference appears to be send needs to parse the params
>> from the string. Do obviously needs to be parsed on the fly too.
>
> Yes, it's the runtime parsing that slows these down.

Here's an example where the overhead should be the same, yet dispatch 
takes only 287 ms to do's 405 ms:

on mouseUp
    put 100000 into n
    put "foo" into tCmd
    --
    -- Test 1: Do
    put the millisecs into t
    repeat n
       do tCmd
    end repeat
    put the millisecs - t into t1
    --
    -- Test 2: Dispatch
    put the millisecs into t
    repeat n
       dispatch tCmd
    end repeat
    put the millisecs - t into t2
    --
    put t1 && t2
end mouseUp

on foo
    get 1+1
end foo

-- 
  Richard Gaskin
  Fourth World Systems
  Software Design and Development for Desktop, Mobile, and Web
  ____________________________________________________________
  Ambassador at FourthWorld.com        http://www.FourthWorld.com



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