On Mon, Sep 6, 2010 at 10:22 PM, wren ng thornton <w...@freegeek.org> wrote: > On 9/6/10 1:33 PM, David Menendez wrote: >> >> For that matter, can you even describe what pure is intended to do >> without reference to<*> or join? > > As already stated: fmap f . pure = pure . f
That's pretty general. For lists, the functions having that property include const [], \x -> [x,x], and repeat. In fact, I think *every* appropriately-typed function satisfies that law. Does anyone know of a counter-example? -- Dave Menendez <d...@zednenem.com> <http://www.eyrie.org/~zednenem/> _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe