From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!feeder.eternal-september.org!gandalf.srv.welterde.de!news.jacob-sparre.dk!franka.jacob-sparre.dk!pnx.dk!.POSTED.rrsoftware.com!not-for-mail
From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: How to Iterate over all elements of a hashed_map.
Date: Tue, 29 Oct 2019 16:56:08 -0500
Organization: JSA Research & Innovation
Message-ID: <qpachq$deo$1@franka.jacob-sparre.dk>
References: <6ea868a2-6f4b-413c-955d-08e8735f2880@googlegroups.com>
 <bfdcdb58-0aa9-42f5-a487-52f21dfa8ffd@googlegroups.com>
 <1559a685-7483-4f2f-8674-d7b61c23bfe8@googlegroups.com>
Injection-Date: Tue, 29 Oct 2019 21:56:10 -0000 (UTC)
Injection-Info: franka.jacob-sparre.dk;
 posting-host="rrsoftware.com:24.196.82.226";
	logging-data="13784"; mail-complaints-to="news@jacob-sparre.dk"
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.5931
X-RFC2646: Format=Flowed; Original
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.7246
Xref: reader01.eternal-september.org comp.lang.ada:57382
Date: 2019-10-29T16:56:08-05:00
List-Id: <comp.lang.ada>

<joakimds@kth.se> wrote in message 
news:1559a685-7483-4f2f-8674-d7b61c23bfe8@googlegroups.com...
> Den tisdag 29 oktober 2019 kl. 15:20:43 UTC+1 skrev Alain De Vos:
>> I found code which takes a different approach, here there is a function 
>> .Iterate public ... ,
>>
>> with Ada.Containers.Indefinite_Hashed_Maps;
>> with Ada.Strings.Hash;
>>
>> with Ada.Text_IO; use Ada.Text_IO;
>>
>> procedure Show_Hashed_Map is
>>
>>    package Integer_Hashed_Maps is new
>>      Ada.Containers.Indefinite_Hashed_Maps
>>        (Key_Type        => String,
>>         Element_Type    => Integer,
>>         Hash            => Ada.Strings.Hash,
>>         Equivalent_Keys => "=");
>>
>>    use Integer_Hashed_Maps;
>>
>>    M : Map;
>>    --  Same as:  M : Integer_Hashed_Maps.Map;
>> begin
>>    M.Include ("Alice", 24);
>>    M.Include ("John",  40);
>>    M.Include ("Bob",   28);
>>
>>    if M.Contains ("Alice") then
>>       Put_Line ("Alice's age is "
>>                 & Integer'Image (M ("Alice")));
>>    end if;
>>
>>    --  Update Alice's age
>>    --  Key must already exist in M.
>>    --  Otherwise an exception is raised.
>>    M ("Alice") := 25;
>>
>>    New_Line; Put_Line ("Name & Age:");
>>    for C in M.Iterate loop
>>       Put_Line (Key (C) & ": " & Integer'Image (M (C)));
>>    end loop;
>>
>> end Show_Hashed_Map;
>
> I confirm that when you want to iterate over a hashed map and want both 
> key and value you need to use the .Iterate function as you do in the 
> example.

That's the reason it exists, of course. Not everything makes sense just with 
elements alone. (A cursor-based iterator is also much more like the existing 
iteration of Ada 95 than the element-based iterators of Ada 2005 and later.)

                          Randy.