On Mon, 2009-03-02 at 13:14 -0500, David Abrahams wrote:
on Mon Mar 02 2009, Rogier van Dalen <rogiervd-AT-gmail.com> wrote:
Shouldn't this go into a more general library? Shouldn't RangeEx by default offer the well-known syntax of function calls?
The only standard syntax I know for stringing together sequence modifications like that is "|"
Do you mean the pipe operator in shell scripts?
(Even though I agree that also providing operator| is sensible, and not very hard at all.)
It should be the only syntax.
We're not only discussing "stringing together sequence modifications" though. The base case under discussion is a single operation. Implicitly you're saying that applying a transformation to all elements should be written as rng | transform (func) rather than transform (rng, func) The former is not standard syntax in C++, nor any other language language: http://en.wikipedia.org/wiki/Map_(higher-order_function) Could you give a rationale for centring your argument around chains of operations, rather than the base case of a single operation?
What we're doing with RangeEx (in general) only expresses a degenerate tree structure (i.e. a linear structure):
Is that true? I've used RangeEx-like facilities (that I wrote) mostly for more complicated trees, such as set operations.
"in general," meaning "most of the time."
What I meant to say was, are you expressing your personal experience with using RangeEx? Or a hunch about what most users will use it for? Or the lazy adaptors that the current version of RangeEx has? FWIW, My personal experience is different.
I do know that I find that "merge()" returning ranges copy (merge (rng1, rng2) | transform (f), output_it); gives expressiveness than ^^^^^^^^^^^^^^^^^^^ Parse error. I don't understand what you're trying to say.
Sorry about that. What I tried to say was that I find copy (transform (merge (rng1, rng2), func), output_it); or, if you wish copy (merge (rng1, rng2) | transform (func), output_it); more expressive than vector <T> intermediate; merge (rng1, rng2, back_inserter(intermediate)); transform (intermediate, output_it, func); Cheers, Rogier