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Programming puzzles: processing lists!
02-14-2019, 05:01 PM
Post: #273
RE: Programming puzzles: processing lists!
On the subject of slow up list operations, there are a couple of ways of speeding up programs where items are appended to an existing list.

One is to store the list in a global (not local) variable. This prevents the system having to save a copy of the original list after every operation.

The best way is to not append items to an existing list in the first place. If there is a way to accumulate the items on the stack and then assemble them into a list using \->LIST that is the fastest way. For example, to create a list of 1000 RANDs:

Slow program:


\<< { }  1. 1000.

Fast program:


\<< 1. 1000.
   NEXT 1000. \->LIST

Of course there are programs where the items must be in a list because intermediate list processing operations need to be performed. Unfortunately using arrays instead of lists will usually not be helpful in these cases.
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RE: Programming puzzles: processing lists! - John Keith - 02-14-2019 05:01 PM

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