Does this monadic Haskell function already exist (or is a simple combination of known functions)?
haskell, monads
Solution
It's also called `flip (foldl (>>=))`.
In general, if you are looking for a function like `[a] -> b`, you are looking for a fold. To compose objects in the monad you might first reach for `(>>=)`. The `flip` is there because `foldl` takes arguments in the opposite order from what you want.
Problem
I'm a relative beginner at Haskell, but with plenty of background in Mathematics, algebra in particular, so statements like "A monad is a monoid in the category of endofunctors" are not a problem for me. Even so, I'm only part of the way to understanding monads in Haskell, and in the course of learning I've found myself writing the following function: ``` bindMap ::(Monad m) => [a -> m a] -> m a -> m a bindMap (f:fs) s = bindMap fs (s >>= f) bindMap _ s = s ``` This serves my purposes completely, but it seems such an obvious function that I thought that either I should be able to find it or define with some simple combinators or (more likely) that I should be thinking about things in a different way. I originally wrote it with the type signature ``` [a -> [a]] -> [a] -> [a] ``` which may give more of an indication of what I'm after. The idea is to join up a list of functions ``` a -> [a] ``` into one big function. I'm using it in a Sudoku solver. If you think there could be more relevant context let me know.