[openbeos] Re: Coding Suggestion -- Templates, Iterators

  • From: "Michael Phipps" <mphipps1@xxxxxxxxxxxxxxxx>
  • To: openbeos@xxxxxxxxxxxxx
  • Date: Sat, 27 Oct 2001 17:04:20 -0400

I 100% agree with you about the typedef. Some things are nearly (if not 
completely)
impossible without typedef (try using pointers to methods without a typedef).

The macro? Well.... I can't say I like the whole #define thing. :-)
The for loop, in general, is for iterations:
for (int i=0; i<10; i++)

That is a paradigm that EVERY C/C++ programmer out there has seen
a bazillion times and understands. The foreach() macro is a new paradigm.
I (as the viewer of your code) would go and look to see what was happening
in there. That slows me down. 

I think that, though, a function (inline, maybe) might work well for sometime 
like that.
Implementation is an exercise for the reader. :-)

>At the risk (ah heck, certainty) of starting a language war, I have a 
>couple of suggestion regarding coding style with C++.
>
>I came across the following code today (actually its from CppTest):
>
>void TestSuite::run (TestResult *result)
>{
>    for (std::vector<Test *>::iterator it = m_tests.begin ();
>            it != m_tests.end ();
>            ++it) {
>               // loop code
>    }
>
>}
>
>(I've snipped out the loop code)
>
>A couple of things occur to me as I stare at this code (besides the 
>fact that I'm not crazy about C++). One is that the template 
>declaration syntax is often extremely awkward to read. In many cases, 
>it makes sense to typedef these buggers into something more friendly. 
>In this example, I would do:
>
>typedef std::vector<Test *>::iterator TestIterator;
>
>Another thing is that iterators are pretty common, so I think having a 
>standard macro for traversing with one would be very useful. Here's my 
>suggestion:
>
>#define foreach(elem,set) for (elem = set.begin (); elem != set.end (); 
>++elem)
>
>Oh, I know, I can hear the groaning out there... "we don't use #define 
>macros -- that's old-style, icky C crap that we sophisticated C++ 
>programmers don't use". Maybe, but I still think macros are extremely 
>useful when used sparingly and judiciously. They're awfully good at 
>hiding uglies.
>
>Now using those two code snippets above, I can rewrite the example 
>(using OpenTracker formatting) as follows:
>
>void
>TestSuite::run (TestResult *result)
>{
>       TestIterator i;
>       foreach (i, m_tests) {
>               // loop code
>       }
>}
>
>Now that's a bit cleaner/clearer. When reading the iterator loop, you 
>have to mentally put the word "in" in there. IOW, read it as "for each 
>i in m_tests".
>
>So whadya think? Love it? Hate it?
>
>

Other related posts:

  1. Home
  2. haiku
  3. Archive
  4. 10-2001