On 10/19/2010 08:28 PM, Michael Van Canneyt wrote:
On Tue, 19 Oct 2010, Sven Barth wrote:
Am 19.10.2010 19:54, schrieb Juha Manninen (gmail):
On Tuesday 19 October 2010 19:10:39 Luiz Americo Pereira Camara wrote:
Yes it's ready in fpc 240:
uses
Fgl;
type
TIntegerList = specialize TFPGList<Integer>;
Well, yes. It is almost as good as a dedicated class. It has a Sort
method but
you must feed the compare function for it.
It does not have a Find method for a binary search in a sorted list.
Indexof does a linear search.
Anyway, it could be used as a base class in Lazarus. I don't know
what is the
Lazarus team's policy for using generics in Lazarus code-base.
In FPC 2.4.0 I had problems with memory consumption of generics
containers.
A<Integer, Integer> map hogged gigabytes of memory while my data
took only
kilobytes (less than 1 MB for sure), on a 64 bit Linux.
Now I have the latest FPC trunk 2.5.1 and the problems are gone. I
added
100000 integers to both a List and to a Map and didn't even notice
the memory
increase in resource monitor.
TIntegerList = specialize TFPGList<Integer>;
TIntegerMap = specialize TFPGMap<Integer, Integer>;
TFPGMap's problem still is that it is not a hash map and is
butt-slow with
lots of data. A hash map is a superior container type, it really
should be
changed.
Besides, people expect to get a hash map when they see "map" in the
class
name. Now they get a list which is deceivingly named as "map".
As you seem to have experience with efficient data structures, what
about creating such a generic hash map? :)
(but don't use 2.4.2rc1 and current/unpatched 2.4.3 as a test base as
those don't have the fixes from trunk to make "specialize" working
again)
Currently, the FPC team is looking at an implementation of Vlado Boza
<us...@ksp.sk> for a standard template library for inclusion in FPC.
The code is on
http://code.google.com/p/stlpascal
Please have a look and comment on it.
I'm not a generics expert and am not in the position to judge whether
this library is good or not.
Michael.
Hash_map implementation shouldn't be a big problem. But I also think,
that other structures can be usefull as well (for example in map done by
red-black tree you can find greatest key which less than X in a good
time, ...).
A is there any decision if it is worth to put it in FPC and where to put it?
Vlad.
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