Re: [boost] Re: Re: Re: Re: Re: Adding Loki to Boost (reprise)

From: Vesa Karvonen (vesa_karvonen_at_[hidden])
Date: 2002-04-13 08:18:04

Joel de Guzman:
>If knowledge of 'fold' et al is required to write an MPL
>algorithm, then it contradicts its primary goal.

I'm not sure about what you are talking about here. I thought that the goal 
of MPL is to facilitate template metaprogramming. One of the things provided 
by MPL (in order to facilitate template metaprogramming) is a sequence 
abstraction and a set of algorithms (higher order functions) for 
manipulating sequences. I don't see how this would contradict the goal of 
MPL.

>Now you are saying that one needs to learn FP (specifically higher
>order functions) to write an MPL algorithm?

No, I don't think that it is strictly necessary to learn about higher order 
functions in order to write algoritms using the MPL, but I can't see why 
someone would want to waste time writing the same pattern matching + 
recursion patterns over and over again.

>I thought that
>the reason why there was the concept of mutators, erase, replace
>etc. was to make it more familiar to the typical STL programmer.

Some of the terminology used in MPL is borrowed from STL, which borrowed 
some of the terminology from functional programming languages. AFAIK the 
idea is to make it easier for STL programmers to understand MPL. This does 
not imply that the MPL primitives would be any less functional.

'erase' and 'replace' are reasonable names for functions in a functional 
setting. Even in FP languages some list manipulation functions may have 
names that one might confuse to be imperative.

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