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From: Maciej Sobczak <no.spam@no.spam.com>
Newsgroups: comp.lang.ada
Subject: Re: How come Ada isn't more popular?
Date: Fri, 09 Feb 2007 11:36:01 +0100
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Date: 2007-02-09T11:36:01+01:00
List-Id: <comp.lang.ada>

Jean-Pierre Rosen wrote:

>> While the inability to return limited types from a function is a bit of
>> an inconvenience, ...
> And you can always return a *pointer* to a limited type, which is what 
> you would do in most other languages.

Which is entirely missing the point.

The purpose of returning limited types from a function is to implement 
the constructor functionality for those types that are considered 
critical and cannot be left uninitialized.

Initialization by procedure is prone to bugs that cannot be checked at 
compile-time (forgetting or bypassing the initialization), same for 
initialization by pointer. Both "solutions" fail to meet the initial 
goal which is to enforce at compile time the proper initialization for 
selected important types.

The ideal solution is called "constructor", everything else is just 
patchwork. Returning limited types is a compromise that can be 
satisfying in most cases - that's why it's good that Ada 2005 provides 
at least this feature.

-- 
Maciej Sobczak : http://www.msobczak.com/
Programming    : http://www.msobczak.com/prog/