Ah! Using repeat for each key is essentially using the keys of an array as a 'proper list' - it is probably the fastest way currently to iterate over a sequence of strings.
In this case the value of each element in that array is immaterial - so the performance benefit comes iterating over the keys in this manner, rather than the way that array was constructed. Mark. Sent from my iPhone > On 20 Aug 2016, at 00:07, Mark Talluto <m...@canelasoftware.com> wrote: > > I do not remember how much of a performance boost we got from manipulating > long lists this way, but if memory serves, it was quite beneficial. > This code sample is just something I made up on the fly. Hopefully it > demonstrates the value of this method. > > command createArray > local tListOfRecordIDs, tTableID > > put fld "recordID data" into tListOfRecordIDs > put uuid() into tTableID > > --FOUND IT FASTER TO WALK THROUGH LONG LISTS > --WHEN WE PUT THEM IN AN ARRAY LIKE THIS > --ONCE THE ARRAY IS MADE, IT WILL BE USED MANY TIMES OVER > --NEGATING THE COST OF MAKING THIS ARRAY > repeat for each line xRecordID in tListOfRecordIDs > put empty into tArrayA[tTableID][xRecordID] > end repeat > > processArray tArrayA > end createArray > > > command processArray @rArrayA > put the keys of rArrayA into tTableID > > --WALK THROUGH ARRAY LIST > repeat for each key xRecordID in rArrayA[tTableID] > --do something with xRecordID here > --we might modify something in this list > end repeat > > --WALK THROUGH ARRAY LIST > repeat for each key xRecordID in rArrayA[tTableID] > --do something with this modified list from previous repeat > end repeat > end processArray > > > -Mark > > > >> On Aug 19, 2016, at 12:22 PM, Mark Waddingham <m...@livecode.com> wrote: >> >> With the current implementation of the engine, the only reason using empty >> is faster than using pValue is because the latter requires a variable >> lookup, the former is a constant. >> >> What are you using sValueCache for? >> >> Sent from my iPhone >> >>> On 19 Aug 2016, at 19:37, Mark Talluto <m...@canelasoftware.com> wrote: >>> >>> >>>> On Aug 19, 2016, at 10:42 AM, Mark Waddingham <m...@livecode.com> wrote: >>>> >>>> command shareAndStoreKey @xArray, pKey, pValue >>>> set the caseSensitive to true -- this is assuming your values are >>>> sensitive to case >>>> if pValue is not among the keys of sValueCache then >>>> put pValue into sValueCache[pValue] >>>> end if >>>> put sValueCache[pValue] into xArray[pKey] >>>> end command >>> >>> >>> Hi Mark, >>> >>> We have been doing: >>> put empty into sValueCache[pValue] --as an optimization. >>> >>> How does this compare to: >>> put pValue into sValueCache[pValue] --in terms of performance? >>> >>> >>> Best regards, >>> >>> Mark Talluto >>> livecloud.io >>> canelasoftware.com >>> >>> >>> >>> >>> _______________________________________________ >>> use-livecode mailing list >>> use-livecode@lists.runrev.com >>> Please visit this url to subscribe, unsubscribe and manage your >>> subscription preferences: >>> http://lists.runrev.com/mailman/listinfo/use-livecode >> >> _______________________________________________ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your subscription >> preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
