You anticipated me. So, is there a core method for foldl/foldr/inject/reduce, or do you have to roll your own as in p5?
On 3/29/08, Larry Wall <[EMAIL PROTECTED]> wrote: > On Sat, Mar 29, 2008 at 10:18:53PM -0400, Mark J. Reed wrote: > : In general, is > : > : [op] (p1,p2,p3,p4...) > : > : expected to return the same result as > : > : p1 op p2 op p3 op p4... > : > : including precedence considerations? > : > : That is, should > : > : [**](2,3,4) > : > : return 2^(3^4)=2^81, or (2^3)^4 = 4096? > > Yes, in fact the section on Reduction Operators uses exponentiation > obliquely in one of its examples of something that should work > right-to-left. Admittedly it's not clearly stated there... > > But the basic idea is always that the reduction form should produce > the same result as if you'd written it out with interspersed infixes. > It's a linguistic construct, not a functional programming construct. > It's not intended to be in the same league as foldl and foldr, and > is only just slightly beyond a macro insofar as it can intersperse > however many operators it needs to for an arbitrarily sized list. > It's not making any attempt to deal with anonymous first-class > functions though. Call a real function for that. :) > > Larry > -- Sent from Gmail for mobile | mobile.google.com Mark J. Reed <[EMAIL PROTECTED]>
