Bruno Mayerle Leite wrote:
> Im trying to implement some features of functional programming in C++. I
> think lazy lists can be useful since we can create infinite lists in some
> functional languages too. Imagine a very big list being traversed by an
> iterator and for some reason when the iterator reaches a certain Node the
> loop is over. In this case it isnt necessary to have the entire big list in
> memory. It is only one point that came to my mind.
Sounds an awful lot like what I tried to do when I first learned C...I
wanted to bring my BASIC baggage with me to use familiar functions like
Left(), Mid(), and Right(). I finally got that _functionality_ when I
moved to Safe C++ but the _implementation_ is different.
I'm sure what you want to do is possible, but it may result in
unreadable/unmaintainable code. Just because something is possible
doesn't mean you should do it. In fact, you _shouldn't_ do it unless
you have a VERY specific reason to do so. Don't write code unless you
actually need it.
The example provided by the document you showed can be done via a very
simple class that increments an internal number:
class IncNumber
{
public:
IncNumber(int Num)
{
MxInternal = Num;
}
inline int GetNext()
{
int x = MxInternal;
MxInternal++;
return x;
}
// Or you could get fancy and do the whole ostream << operator thing.
private:
int MxInternal;
};
IncNumber MyNum(1);
for (x = 0; x < 10; x++) cout << MyNum.GetNext() << endl;
Now I realize that it was just an example, but what I'm trying to say is
that there is no need to write
unmaintainable/unreadable/non-understandable code if you can avoid it.
There's almost always a better way to implement something.
--
Thomas Hruska
CubicleSoft President
Ph: 517-803-4197
*NEW* VerifyMyPC 2.5
Change tracking and management tool.
Reduce tech. support times from 2 hours to 5 minutes.
http://www.CubicleSoft.com/VerifyMyPC/
