[fpc-pascal] IntList

[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".


Juha