Re: GCC 4.0 Ada.Containers Cursor danger.

["Dmitriy Anisimkov" <anisimkov@yahoo.com>]

<<If you remove cursors, like for example from Insert/4,
then you will definitly have algorithms that will run
more slowly using more memory cells or register cells.>>

Depend on what to do with returned cursor later.
In some cases it would be enought to have Insert_Or_Replace without
cursors routine.

<<I'm assuming you somehow found a way around the case where you have
to compare strings and/or hash them in order to repeatedly
find a key? Or how do you remember a position in a dynamic container?>>


Algorithm should be designed for be able to get value by key just once.
Use and modify it and put it back. Other option is to use
Generic_Update_Element routine.

<<And how do you _not_ loose efficiency if on every loop
iteration you check the validity of your variables related
to container elements? >>

Iteration could be done in the generic routine too.  Like in
Generic_Iteration but with a one more out parameter "Quit : out
Boolean" in Process procedure generic parameter.

<< If there were a number of generic algorithms working on
top of Ada.Containers, would they be useful in your work?

How about idiomatic uses of the library? >>

AWS (Ada Web Server) was based on ADT containers before move to AI302
containers.  I found a lot of errors in AWS after move to AI302, all of
them was a broken memory on invalid cursors.

I'm using ADT containers to keep forex trading accounts, prices,
positions and configuration of the operative part of the Internet
Currency Trading system.
There is a indexed containers

Currency_Pairs
Accounts
Accounst in Currency_Pairs
Currency_Pairs in Accounts
Trades
Trades in Accounts/Currency Pairs

Some of the elements linked directly by Access type.

The operations on them is get by key, modify by key, iteration untill
condition, and all of them is without cursors and without find more
then once.