Category:Monads: Difference between revisions

In functional programming, the [[wp:Monad_(functional_programming)|Monad]] design pattern is a general solution to the problem of nesting (or 'composing') a class of functions which enclose their output values in some kind of useful wrapping. The output envelope might, for example, contain, in addition to the returned value, a log string, or a boolean indicator of whether or not the input was a legal value. Sometimes the output might simply be enclosed in a list representing a range of possible values rather than a single value.