Re: Table of pointers question

[Rob Solomon <usenet@drrob1-noreply.com>]

On Sat, 26 Sep 2009 11:51:48 -0700, Dennis Lee Bieber
<wlfraed@ix.netcom.com> wrote:

>On Sat, 26 Sep 2009 09:36:26 -0400, Rob Solomon
><usenet@drrob1-noreply.com> declaimed the following in comp.lang.ada:
>
>
>> When  I did the same routine in Modula-2, I structured it the same
>> way, only used an array of pointer rather than indices.   AFAIK,
>> Modula-2 does not have the capability to place data in the heap and
>> return a pointer in one assignment.  
>>
>	Based on the example at http://www.modula2.org/tutor/chapter11.php,
>no... They use ALLOCATE() to create one structure on the heap,
>specifying the size (apparently Modula-2 either doesn't have the
>intelligence to infer the data size, of they also use it to create
>dynamic arrays of smaller components); followed by assigning values to
>the allocated memory.
>
>	In Ada, "new" is the keyword that allocates memory... There is no
>equivalent "free" as, in the realm Ada was originally spec'd for,
>garbage collection operations would have been detrimental. There is a
>generic "unchecked_deallocation" procedure -- as the name should
>indicate, usage is really up to the programmer to ensure they aren't
>leaving dangling references, etc.
>
>	Note that, as with Pascal, Modula-2 requires the user to explicitly
>code pointer dereference operations. Ada rarely needs such as one can
>not perform arithmetic on access types.

I could have been clearer as to my meaning.  ALLOCATE creates a
pointer to an empty object.  A separate assignment statement is
required to add the data.  That is, Modula-2 needs 2 statements to
achieve what Ada is allowing in that one statement.

This contraction confused me.  

If I come across any embedded assignment statements in this Ada book,
like is allowed in C, I'll give up.