Re: Table of pointers question

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

>Rob Solomon <usenet@drrob1-noreply.com> writes:
>
>>   EntryList        : array (1..MaxEntries) of DirectoryEntryType;
>>   EntryPointerList : array (1..MaxEntries) of DirectoryEntryPointerType;
>
>> My question is that I would expect to have an array that contains the
>> data, 
>
>That might appear to be EntryList. Except that EntryList is never used
>in the code you quoted. I don't have the book handy, so I don't know
>if it is used elsewhere.
>
>> and a second array that is an array of pointers to the 1st array.
>
>That's EntryPointerList. However, the pointers simply point to
>allocated memory, not to elements of EntryList or any other data
>structure. 
>
>Why did you expect pointers into an array?
>
>> The example does not define that.
>>
>> How does the line:
>> EntryPointerList(NumberOfEntries) := new DirectoryEntryType'(NewEntry)
>> ;
>>
>> Do what's needed?
>
>This allocates memory for the data contained in NewEntry, and stores a
>pointer to it in EntryPointerList.
>
>The rest of the code then moves these pointers around in
>EntryPointerList.
>
>What other languages are you familiar with? Perhaps we could relate
>this Ada code to one of them.

I am very familiar with Wirth languages.  I have been using Modula-2
since the 80's.  

Some of my confusion can be due to the fact that I am merely a
recreational programmer that programs for his own use and amusement.