Hi, On Thursday 22 October 2009 09:47:32 Martijn van Steenbergen wrote: > Bonjour café, > > > data ExprF r > > = Add r r > > > > | Sub r r > > | Mul r r > > | Div r r > > | Num Int > > This is a well-known pattern that for example allows nice notation of > morphisms. But what is it called? > ...
The multirec package calls this the "pattern functor" (more accurately, it generates a sum-of-products-like higher order functor whose fixed point is isomorphic to your family of types, and calls that the pattern functor). -- Greetings, Daniel _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe