Playing with clojure monads

monad.clj

(ns playground.monad
  (:use [clojure.algo.monads :only 
    [domonad defmonadfn with-monad state-m fetch-state set-state 
     update-state m-fmap]]))
     
(def get-name
  (domonad state-m
    [a (fetch-state)]
    (:name a)))

(defn upper [s]
  (.toUpperCase s)) 

(def scream
  (domonad state-m
    [a-name get-name]
    (upper a-name)))

(defmonadfn screaming-title [s]
    (m-bind get-name 
            (comp m-result (partial str s " - ") upper)))

;
; To run screaming-title
; ((with-monad state-m 
;     (screaming-title "hello")) {:name "roman"})
; -> "hello - ROMAN"
;
; In order to run this function we need to use the with-monad call, this
; because the function is using m-bind and m-result as abstract functions.
;------------------------------------------------------------------------------
; To run scream
; (scream {:name "esse"})
; -> "ESSE"
;
; This function doesn't require the with-monad call, given that we already
; binded the domonad.
;