Re[2]: [fpc-pascal] about dynamic array
Hello FPC-Pascal, Sunday, May 9, 2010, 8:04:24 PM, you wrote: s Sorry to have launched such an argument by starting a new s thread about dynamic array. My purpose, as a newcomer discovering s the world of fpc, was just to get information I could not find s myself to help me and progress in the jungle ;-) From every discussion something new emerge :) -- Best regards, José ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: Re[2]: [fpc-pascal] about dynamic array
c TList wraps TFPList, which is based internally on an array. So access c is fast; insertion, deletion not. But it is faster than inserting elements in a dynamic array (unless reference counted ones) because it usually moves less amount of data (4/8 bytes per element). Implementing a dynamic array via a list implementation which is based on a dynamic array. Sure, that's faster. -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01 ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re[2]: [fpc-pascal] about dynamic array
Hello FPC-Pascal, Thursday, May 6, 2010, 3:53:59 PM, you wrote: c TList wraps TFPList, which is based internally on an array. So access c is fast; insertion, deletion not. But it is faster than inserting elements in a dynamic array (unless reference counted ones) because it usually moves less amount of data (4/8 bytes per element). -- Best regards, José ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re[2]: [fpc-pascal] about dynamic array
Hello FPC-Pascal, Thursday, May 6, 2010, 8:58:33 PM, you wrote: faster in fact. If the user plans to use a record (which is my suspect) with TList he must new and dispose the elements and he will end up with a dyn array of pointers after all, which is a TList. FK A dyn. array of records requires no new/dispose as well as no type casts FK as TList does. OK, I see :) Do you remember how this ver long thread starts ? A: array of MyArray; SetLength(A,x); A[0]:=MyArrayElement; Move(A,B,sizeof..); Entering the doom again... Next question could be why: p1: TObject; p2: TObject; p1:=TObject.Create(); p2:=p1; P1.free; p1:=nil; Why I get an AV if accesing p2 ? Because the object has been freed... So why is not p2 = nil as p1 ? This kind of messages will end up or in a master class of pointers for dummies or a lot of developers dropping the list for days. I had proposed the solution that I think is easy to understand what happends behind the scenes or maybe I wrongly choose the moment of hit reply :( -- Best regards, José ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re[2]: [fpc-pascal] about dynamic array
Hello FPC-Pascal, Thursday, May 6, 2010, 9:50:34 PM, you wrote: DC The short answer is because you have not set p2 to nil as you did to p1. I do not want to be rude but, do you read all the message ? I was trying to be ironic, but seems that I was unable maybe due my very limited english, sorry. -- Best regards, José ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
