Is there any scala library that treat tuples as monads

Question

Is there any scala library that enriches basic scala tuples with monad syntax. Something similar to the Writer monad but adjusted for usage with tuples.

What I look for:

val pair = (2, "as")
pair >>= (a => point(a+1))

should equal to (3, "as"). As well as

for (p <- pair) yield (p+1)

Answer 1

Yep, Scalaz provides monad instances for tuples (up to Tuple8):

import scalaz.std.anyVal._, scalaz.std.tuple._, scalaz.syntax.monad._

scala> type IntTuple[A] = (Int, A)
defined type alias IntTuple

scala> pair >>= (a => (a+1).point[IntTuple])
res0: (Int, String) = (2,as1)

scala> for (p <- pair) yield (p + 1)
res1: (Int, String) = (2,as1)

(Note that the type alias isn't necessary—it just makes using point a little easier.)