On Thu, Sep 29, 2016 at 2:43 AM, Random832 <random...@fastmail.com> wrote: > On Wed, Sep 28, 2016, at 11:41, Paul Moore wrote: >> What "allows side effects" in languages like Haskell is the fact that the >> runtime behaviour of the language is not defined as "calculating the >> value of the main function" but rather as "making the process that the >> main functon defines as an abstract monad actually happen". > > Well, from another point of view, the output (that is, the set of > changes to files, among other things, that is defined by the > monad-thingy) is *part of* the value of the main function. And the state > of the universe prior to running it is part of the input is part of the > arguments.
That's exactly how a function works in an imperative language, and it's exactly what the FP advocates detest: opaque state. So is the difference between "function" and "monad" in Haskell the same as "pure function" and "function" in other contexts? ChrisA -- https://mail.python.org/mailman/listinfo/python-list
