On Sat, Apr 19, 2008 at 07:37:50PM -0500, Creighton Hogg wrote: > This isn't about Haskell per se, but I was reading the old Meijer et al. > paper > "Functional Programming with Bananas, Lenses, Envelopes and Barbed Wire" & I > think there's a notational pun that's really confusing me. > On page 12 we have the CataEval equation > (|phi|) . in = phi . (|phi|)_L > Now, the subscript L & the following example of cons lists implies that L is a > functor in this equation, yet the line immediately after this equation says > that "(CataEval) states how to evaluate an application of (|phi|) to an > arbitrary element of L...." so then that makes it sound like the L here is the > fixed point of some functor F, not the functor itself.
Yes, the explanatory text should say mu L instead of L. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
