Lisp vs. C++ (not off-topic)

[Lionello Lunesu]

Sean Kelly wrote:
> Oh, a quick comment on loops, since the article mentions those as well. 
>  Here is the Lisp code:
> 
>     (loop for word in (gethash n *dict*) do
> 
> 
> His C++ version:
>     for (HashMap::iterator i = gDict.equal_range(n).begin();
>          i != gDict.equal_range(n).end(); i++)
> 
> In D, if the words were stored in a sorted array, I would write:
> 
>     foreach( word; dict[lowerBound(n) .. upperBound(n)] )
> 
> 
> And if they were in an AA (char[][][int] dict):
> 
>     foreach( word; dict[n] )
> 
> Note that this expects the lookup for n to succeed or the current AA 
> code will throw an exception.  A more robust version:
> 
>     char[][]* list = n in dict;
>     if( list ) foreach( word; *list )
> 
> seems unnecessarily wordy and somewhat unreadable.  It would be nice if 
> AAs had some lookup method that returned a default value on failure 
> instead of requiring the pointer check above.

Perhaps foreach could always check for 'null' if you pass it a pointer 
to an array.

L.