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=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,4f316de357ae35e9
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-07-30 21:52:35 PST
Path: archiver1.google.com!postnews1.google.com!not-for-mail
From: bam@snoopy.apana.org.au (Brian May)
Newsgroups: comp.lang.ada
Subject: Re: FAQ and string functions
Date: 30 Jul 2002 21:52:34 -0700
Organization: http://groups.google.com/
Message-ID: <29e5ffff.0207302052.465a3193@posting.google.com>
References: <20020730093206.A8550@videoproject.kiev.ua>
 <4519e058.0207300548.15eeb65c@posting.google.com>
NNTP-Posting-Host: 203.25.148.63
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Trace: posting.google.com 1028091154 23528 127.0.0.1 (31 Jul 2002 04:52:34
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: 31 Jul 2002 04:52:34 GMT
Xref: archiver1.google.com comp.lang.ada:27506
Date: 2002-07-31T04:52:34+00:00
List-Id: <comp.lang.ada>

> Strings in Ada are particularly tricky for newcommers. One trap is
> underuse of perfectly sized string constants. Most strings get their
> value once and never need it changed. If that is the case, its fairly
> easy to declare the string at the point its value is known, with the
> perfect bounds, by using a string constant (possibly inside a
> "declare" block). If you do that, it becomes very easy to deal with.

I have two questions concerning strings that I can't find answers for
in the RM:

1. How do I split a string up into tokens and iterate through the list
of tokens (compare with C's strtok function)?

2. Can this ugly looking code be simplified?

      declare
         I    : Iterator;
      begin
         I := Element_Iterator(Class_Element,"parent");
         while More(I) loop
            declare
               My_Node : Node renames Value(I);
               Class_Ref : DOM_String renames
Get_Attribute(My_Node,"ref");
            begin
               Put_Line(Class_Name(Package_Id,Class_Ref)&"($1,$2,$3)");
            end;
            Next(I);
         end loop;
         Free(I);
      end;

where Element_Iterator, More, Value, Next, and Free are my own
functions to iterate over elements in a DOM tree in xmlada (without
these the code was a real mess). DOM_String is similiar to a string
(in fact, I think internally it is defined as a string, but don't
quote me on that).

Ideally I don't want to have the nested declare block for the sole
purpose of
saving the result from Get_Attribute, but I am not sure this is
possible?

eg. I would like to be able to say

      declare
         I    : Iterator;
         Class_Ref : DOM_String;
      begin
         I := Element_Iterator(Class_Element,"parent");
         while More(I) loop
            Class_Ref := Get_Attribute(Value(I),"ref");
            Put_Line(Class_Name(Package_Id,Class_Ref)&"($1,$2,$3)");
            Next(I);
         end loop;
         Free(I);
      end;

but do it in a legal way. I think this would make the code more
readable.

Any comments?