2008年9月5日 · A monad appears to be a "comprehensible unit which is predictable upon its full understanding" -- If you understand "Maybe" monad, there's no possible way it will do anything except be "Maybe", which appears trivial, but in most non monadic code, a simple function "helloworld" can fire the missiles, do nothing, or destroy the universe or even ...

2010年4月24日 · The monad is the "glue code" executed before and after each evaluated argument. This glue code function "bind" is supposed to integrate each argument's environment output into the original environment. Thus, the monad concatenates the results of all arguments in a way that is implementation-specific to a particular monad.

2011年12月3日 · Monads capable of this are called "vernünftige Seelen" or "Geister" (intelligent souls or spirits, "animae"). Now, there is a hierarchy of monads with regard to their apperceptions: From "schlummernden" (slumbering) up to the omniscient monad, the "monas monadum" (monad of monads) – God. Somewhere in between are animal and spirit monads.

A monad is a highly composable unit (a kind of building block of programming) in functional programming. (IMO, introducing "Monad laws" without any context and rationalization is merely a useless classification and hazard to understand the concept.

That's why Bind takes a func from T to Monad<U>-- because the whole point of the thing is to be able to take a function g from T to Monad<U> and a function f from U to Monad<V> and compose them into a function h from T to Monad<V>. If you want to take a function g from T to U and a function f from U to Monad<V> then you don't need Bind in the ...

2011年12月19日 · (See also my previous thoughts on magicMonadUnwrap :: Monad m => m a -> a) Suppose I tell you I have a value which has the type [Int]. Since we know that [] is a monad, this is similar to telling you I have a value which has the type Monad m => m Int. So let's suppose you want to get the Int out of that [Int]. Well, which Int do you want? The ...

2010年8月1日 · The Continuation monad is especially brain-breaking, but mathematically join is actually rather neat here: M(X) corresponds to the "double dual space" of X, what mathematicians might write as X** (continuations themselves, i.e. maps from X->R where R is a set of final results, correspond to the single dual space X*), and join corresponds to an ...

2014年1月7日 · For example, monad comprehensions were turned into list comprehensions. Similarly, to remove the do type class issue, the MonadZero class was removed; for the use of do, the method fail was added to Monad; and for other uses of …

2015年1月5日 · What I think you might actually want is the Functor and not the Monad. That is the fmap : (a->b) -> f a ...

2020年1月26日 · I note that your sequence monad does not implement the sequence monad. The characteristic behaviour of the sequence monad is that the bind operation's behaviour is map-and-concatenate. That is, if we have a sequence of ints s equal to {1, 2, 3}, then s.Bind(x => Repeat(x, 2)) is the sequence {1,1,2,2,3,3}, for example. Your implementation does ...