There should be a "unique" option on sort . . .

[Richard Gaskin]

Peter Haworth wrote:
> Your handler to use an array isn't quite the same as mine. You have a
> repeat loop adding 1 to the key to create the array whereas I used combine.
> Be interesting to see if that makes any significant difference.

Good catch.  The arithmetic operation isn't needed there (I just blindly 
copied-and-pasted from some old MetaCard stuff and revised it only to 
use my var names), so conceivably it could be slightly faster to omit 
the arithmetic and just put empty into that array value.

Or so it would seem....

I couldn't resist trying this, so I just ran another test with two array 
functions, one being the original and the other replacing this:

       add 1 to tA[tLine]

...with this:

       put empty into tA[tLine]

Here's the results:

10 iterations on 100000 lines of 5 or fewer chars:
Non-Arithmetic Array: 499 ms (49.9 ms per iteration)
Original Array: 470 ms (47 ms per iteration)
Results match - Each list has 996 lines


I'm guessing this has to do with a certain amount of overhead associated 
with strings.

So then I tried another variant, in which it puts a value that has been 
coerced to a number into the array slot:

function UniqueListFromArray2 pData
    put 0+0 into y
    repeat for each line tLine in pData
       put y into tA[tLine]
    end repeat
    put the keys of tA into tKeys
    sort lines of tKeys
    return tKeys
end UniqueListFromArray2

And the results:

10 iterations on 100000 lines of 5 or fewer chars:
"Add 1" Array: 479 ms (47.9 ms per iteration)
"Put Y" Array: 530 ms (53 ms per iteration)
Results match - Each list has 993 lines

Hmmm.....

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  Richard Gaskin
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