Re: [fpc-pascal] Procedural generics question
> I remember something like this in RTTI though but can't find it in your
docs yet for generics.
{$mode objfpc}
uses
typinfo;
generic procedure Add;
begin
if TypeInfo(T) = TypeInfo(Integer) then WriteLn('an integer');
if TypeInfo(T) = TypeInfo(String) then WriteLn('a string');
end;
begin
specialize Add;
specialize Add;
end.
--
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[fpc-pascal] Procedural generics question
Inside a generic procedure (no objects used just a procedure) is there a way to check which type the code is being used for such as: generic procedure Add(); begin if type = integer then... if type = string then... begin // specialized code for that type only end end; I remember something like this in RTTI though but can't find it in your docs yet for generics. The current way might be to code up separate procedures for each type, but that's kind of defeating the purpose of generics since that would simply be an overloaded regular function. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How reliable are Hashlists in Contnrs
On 2020-08-24 14:01, nore...@z505.com wrote: I've noticed some problem with another hashlist that after adding about 2000 items to it, it starts to have problems. BTW, sorry to be more clear I meant I used another hashlist unit, not the contnrs one but another open source public domain one This one: https://github.com/z505/delphi-hashlist And had problems with it. I will try out contnrs one to compare soon! ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Difference between Associative array and Hashlist?
Am 24.08.2020 um 21:47 schrieb Lars via fpc-pascal: Since FPC has no associative array I was thinking that the closest is TStringList with name/value pairs. Then there is a hashlist in contnrs. Maybe an associative array means you don't have to implement it using hashes in order for it to work? If there is a need for one I might write one as the TStringList is a bit slow, but do they already exist elsewhere before undertaking it... I suggest you to take a look at TDictionary<,> in Generics.Collections. You can find a comparison regarding performace of various hash list classes available with/for FPC here: http://www.benibela.de/fpc-map-benchmark_en.html Regards, Sven ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How reliable are Hashlists in Contnrs
Am 24.08.2020 um 21:01 schrieb Lars via fpc-pascal: I've noticed some problem with another hashlist that after adding about 2000 items to it, it starts to have problems. There are duplicates added (possibly a collision?) Is there a such thing as a perfect hashlist which never has a collision, or will they always have problems... In that case a regular but slower List might be of use for perfection. If there is an error would it throw an exception? Hash lists will always create collisions if enough elements are added. After all their purpose is to speed up the search thus they reduce the search space. This is by design. If there should really be a problem with adding an element then an exception will be thrown. Regards, Sven ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How reliable are Hashlists in Contnrs
On Mon, Aug 24, 2020 at 9:25 PM Lars via fpc-pascal wrote: > Is there a such thing as a perfect hashlist which never has a collision, No, there are infinite possible items you can add to a haslist, but only a finite number of available hashes. It's the pigeon hole principle: https://en.wikipedia.org/wiki/Pigeonhole_principle -- Bart ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] Difference between Associative array and Hashlist?
Since FPC has no associative array I was thinking that the closest is TStringList with name/value pairs. Then there is a hashlist in contnrs. Maybe an associative array means you don't have to implement it using hashes in order for it to work? If there is a need for one I might write one as the TStringList is a bit slow, but do they already exist elsewhere before undertaking it... ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] How reliable are Hashlists in Contnrs
I've noticed some problem with another hashlist that after adding about 2000 items to it, it starts to have problems. There are duplicates added (possibly a collision?) Is there a such thing as a perfect hashlist which never has a collision, or will they always have problems... In that case a regular but slower List might be of use for perfection. If there is an error would it throw an exception? ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Lazarus start problem after power outage on RPi4
On Mon, 24 Aug 2020 09:59:19 +0200, Mattias Gaertner via fpc-pascal wrote: >> Can I copy this file from an RPi3B where I have installed the same >> versions of Lazarus and Fpc in the same file locations (I use the same >> install scripts on all RPi:s)? > >Yes. >After start fix the paths in Tools / Options / Env. / Files to point to >the right fpc. Same paths, different RPi. It worked fine so I can continue working where I left off. Thanks. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Regression in 3.2.0 ??
Thanks to Sven & Michael for commenting. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Lazarus start problem after power outage on RPi4
On Mon, 24 Aug 2020 09:12:19 +0200 Bo Berglund via fpc-pascal wrote: > Tonight there was a power outage in my home where I have a RaspberryPi > 4B development system with Lazarus 2.0.8 and Fpc 3.0.4. > > When it happened the system was running including Lazarus. > Now when I start Lazarus I get to a dialog saying: > > - > Upgrade configuration > THere is already a configuration from version prior to 2.0.8 in > /home/pi/.lazarus_2.0.8 > The old configuration will be upgraded. > If you want to use two different Lazarus versions you must > start the second Lazarus with the command line parameter > primary-config-path or pcp > > > [Abort] [Upgrade] > - > > Obviously my start desktop file for Lazarus specifies to use pcp as I > have several versions of Lazarus installed. > > In order not to break anything I used Abort and started checking the > content of my config dir and comparing to another 2.0.8 version. > > What I found is that there are 3 files in the problem dir that have > suspicious timestamps/sizes: > > -rw-r--r-- 1 pi pi306 Aug 24 03:59 EditorMacros.xml > -rw-r--r-- 1 pi pi 0 Jan 1 1970 environmentoptions.xml > -rw-r--r-- 1 pi pi 2883 Aug 24 03:59 inputhistory.xml > > In the other Lazarus 2.0.8 config dir (set to use fpc 3.2) these files > are as follows: > > -rw-r--r-- 1 pi pi 9735 Jun 21 17:13 environmentoptions.xml > -rw-r--r-- 1 pi pi712 Jun 21 17:13 inputhistory.xml > > EditorMacros.xml is missing in the other dir. > > > What to do? It seems like the environmentoptions.xml got hosed in the > power outage... > > Can I copy this file from an RPi3B where I have installed the same > versions of Lazarus and Fpc in the same file locations (I use the same > install scripts on all RPi:s)? Yes. After start fix the paths in Tools / Options / Env. / Files to point to the right fpc. > I really do not want to lose any of what I worked on last night before > I stopped at 00:31 after finally fixing a persistent bug. Mattias ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] Lazarus start problem after power outage on RPi4
Tonight there was a power outage in my home where I have a RaspberryPi 4B development system with Lazarus 2.0.8 and Fpc 3.0.4. When it happened the system was running including Lazarus. Now when I start Lazarus I get to a dialog saying: - Upgrade configuration THere is already a configuration from version prior to 2.0.8 in /home/pi/.lazarus_2.0.8 The old configuration will be upgraded. If you want to use two different Lazarus versions you must start the second Lazarus with the command line parameter primary-config-path or pcp [Abort] [Upgrade] - Obviously my start desktop file for Lazarus specifies to use pcp as I have several versions of Lazarus installed. In order not to break anything I used Abort and started checking the content of my config dir and comparing to another 2.0.8 version. What I found is that there are 3 files in the problem dir that have suspicious timestamps/sizes: -rw-r--r-- 1 pi pi306 Aug 24 03:59 EditorMacros.xml -rw-r--r-- 1 pi pi 0 Jan 1 1970 environmentoptions.xml -rw-r--r-- 1 pi pi 2883 Aug 24 03:59 inputhistory.xml In the other Lazarus 2.0.8 config dir (set to use fpc 3.2) these files are as follows: -rw-r--r-- 1 pi pi 9735 Jun 21 17:13 environmentoptions.xml -rw-r--r-- 1 pi pi712 Jun 21 17:13 inputhistory.xml EditorMacros.xml is missing in the other dir. What to do? It seems like the environmentoptions.xml got hosed in the power outage... Can I copy this file from an RPi3B where I have installed the same versions of Lazarus and Fpc in the same file locations (I use the same install scripts on all RPi:s)? I really do not want to lose any of what I worked on last night before I stopped at 00:31 after finally fixing a persistent bug. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
