7 Sep
2010
7 Sep
'10
11:22 a.m.
On Mon, Sep 6, 2010 at 10:22 PM, wren ng thornton <wren@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 <dave@zednenem.com> <http://www.eyrie.org/~zednenem/>