Re: [boost] Interest for a perl6-like-junctions-class?

From: FlSt_at_[hidden]
Date: 2005-08-06 08:53:13

Rob Stewart wrote:

>From: FlSt_at_[hidden]
>  
>
>>Rob Stewart wrote:
>>    
>>
>>>From: FlSt_at_[hidden]
>>>
>>>I just tried that version tonight.  So far, it has taken well
>>>over 30 minutes to compile junction_example.cpp, and it's still
>>>      
>>>
>
>It took just over 39 minutes to complete.
>
g++ 4.0.1 is a lot faster, but needs more RAM (as I saw with top). 
Compilation times of my test program with the new version:

g++4.0.1  1,5 minutes
g++3.3.6  7,5 minutes
g++2.95  3,75 minutes

I'm using Linux and tested the compilers with -O0 -g -Wall -W options 
(no optimizing and debug infos) and the "time" command for the 
compilation time measurement. I think comparisons with optimizing 
activated makes no sense, because the compiler version are to different.

>>test program. I removed the xxx_of functions for STL-Iterators, because 
>>Ranges of STL-Iterators can be generated with make_iterator_range( 
>>begin, end )
>>
>
>I haven't looked at supporting pairs of iterators yet.  You're
>right that one can use make_iterator_range, but if we can use a
>pair right out of the box, all the better
>
see below. There is another reason why I removed them.

>>    
>>
>
>I switched back to your test program and it again took a very
>long time to compile.  When I ran it, it dumped core due to what
>looks like infinite recursion (SIGSEGV).
>
No, the problem is that you removed the storage of the Range. When you 
create a instance of a junction with the STL-iterator-range with 
boost::range::make_iterator_range() it creates a temporary object which 
is lost after creating the junction creation. That was the secons reason 
I removed the STL Ranges support. ;-) In my new version (v9) I use 
references to the range. ( But I think the cost of holding a range would 
be minimal. )

>
>BTW, you should consider writing your tests such that you don't
>have to visually inspect each test each run to decide whether
>you're getting the correct answer.  Do you save a vetted copy of
>the output and diff the output of a new run against that each
>time?
>
No :-). I have seperate test programs, which I haven't put into the zip 
file, because they are still under construction.

>Also, you should not put your code directly into namespaceboost.
>Following Boost guidelines, you'd create a "junctions" namespace
>for everything.
>
>  
>
Ok, will be done for the next version

Sincerly
  Florian