----- Original Message ----- From: "Rob Stewart" <stewart@sig.com> To: <boost@lists.boost.org> Cc: <boost@lists.boost.org> Sent: Tuesday, January 11, 2005 1:18 PM Subject: Re: [boost] Re: Re: Re: Re: Functions as Filters (was Program Reuse...)
From: christopher diggins <cdiggins@videotron.ca>
From: "Jonathan Turkanis" <technews@kangaroologic.com>
void DoWork() { // do work }
int main() { DoWork(); }
Okay, but do you really expect people to start writing programs this way?
Yes, especially if the iostreams library provides the functionality to them. My point is that C++ code is pointlessly hard to reuse as is, and I am pushing for new ways to make small programs more reusable. This is incrediby important when managing large numbers of small programs (for instance library tests and demos). It is trivial to refactor code to make it look like the above, just cut and paste the main!
You assume that nothing fails in the above, since main() falls through and, therefore, returns zero. Are you proposing that main() should actually catch exceptions and, possibly, extract its exit status from the exception object?
No I am not proposing that. I don't care at this point how a programmer chooses to deal with that.
I think people would only do this to conform to your filter concept. My question is: why aren't the other concepts sufficient?
The other concepts are fine, they are just more obfuscated than most programmers require. Just imagine trying to explain how to use a filter
You've admitted to being relatively new to C++. Can you rightly determine what "most programmers require?"
First off, I said "I'm not exactly wet behind the ears". Exactly how much, or how little I know about C++ should be irrelevant. I think it is extremely rude to put someone's credentials into question in such a discussion. If you disagree with something I said, then please state why, don't question the validity of my opinion.
concept in a way which makes sense to a Java / Delphi / C programmer. I think it is important to try and provide alternatives where possible which makes sense to professional programmers who may not be familiar with the intricacies of generic programming techniques and functors.
A reasonable goal, though all C++ programmers need to become familiar with generic programming and function objects. These really aren't novel or academic techniques.
No, but they are overkill in cases when a void procedure will do just as well.
Nonetheless, I do currently have a non-trivial program which converts C++ into a <pre></pre> html tag, CppToHtmlPreTag, it operates obviously on the stdin and outputs to stdout. It looks essentially like this:
void CppToHtmlPreTag() { // calls multiple other functions to do the work };
int main() { CppToHtmlPreTag(); return 0; }
So the result of this program is to write "<PRE>" to stdout, copy stdin to stdout, and write "</PRE>"? Why do you need a program for that?
Sorry I was unclear, the CppToHtmlPreTag adds <div class="xxx"></div> tags around the various syntactic elements so that a css document can control coloring. [big snip]
This would be even easier to assemble via scripting and you don't need to compile anything or maintain source and binaries independently.
I am perfectly aware of how to use the various shells and scripting languages. I don't see how that is relevant to a discussion of C++ techniques. CD