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

From: FlSt_at_[hidden]
Date: 2005-07-28 01:49:50

>
>
>>>>[...]
>>>>
>If that is a useful expression, it's more of a set operation than
>a junction operation (as exemplified by Perl's junctions) anyway,
>
http://www.linux-magazine.com/issue/38/Perl_BlackJack.pdf.
This is the article from where my idea comes to have something similar 
in C++ (I read the German translation in Linux Magazin 12/2003)

>right?  Besides, normal algorithms can be used to express that
>quite succinctly.  Do you need a new type for it?  Maybe.  I
>don't think it should be merged with the simpler ideas from Perl
>junctions.  I think they are orthogonal behaviors, and the
>complexity argues against one type doing both tasks.
>  
>
The Perl junctions aren't simpler, in Perl you can call functions either 
in a scalar context or in a list context. The called function can 
determine in which context it is called and return a scalar or a list. I 
think my mistake was, I tried to bring this concept into C++ for 
junctions, but it doesn't fit into the C++ type system. And there was no 
example for this in the article I denoted in my first message.

A junction without junction result type and arithmetic operations is 
something completely different I had in mind at the beginning of this 
discussion. What remains now at the view point of the client are the 
four functions any_of<T>, all_of<T>, one_of<T> and none_of<T> and the 
comparison operators. The XXX_of functions should operate on ranges or 
containers. I aggree.

Florian