Peter Verswyvelen
Haskell seems to have pretty strong support for dynamic casting using Data.Typeable and Data.Dynamic. All kinds of funky dynamic programming seems to be possible with these "hacks".
Is this considered as being as bad as - say - unsafePerformIO? What kind of evil is lurking here?
Uncertainty. Noone on #haskell seems to know how Typeable-dispatches compare to pattern matching wrt. performance, and I was either too lazy or too uninterested to measure it myself. Combined with a custom type class and existentials, they safe you from writing catch-all ADTs and thus give code flexibility (and conciseness), while retaining static typing, modulo unexhaustive pattern warnings. This is how XHB uses Typeable, and, IMHO, it's a Good Thing. -- (c) this sig last receiving data processing entity. Inspect headers for copyright history. All rights reserved. Copying, hiring, renting, performance and/or quoting of this signature prohibited.