add protocols

Author: sovelten

src/state_flow/protocols.clj

@@ -0,0 +1,44 @@
+(ns state-flow.protocols)
+
+(defprotocol Functor
+  "A data type that can be mapped over without altering its context."
+  (-fmap [ftor f fv] "Applies function f to the value(s) inside the context of the functor fv."))
+
+(defprotocol Applicative
+  "The Applicative abstraction."
+  (-fapply [app af av]
+    "Applies the function(s) inside af's context to the value(s)
+     inside av's context while preserving the context.")
+  (-pure [app v]
+    "Takes any context or monadic value `app` and any value `v`, and puts
+     the value `v` in the most minimal context (normally `mempty`) of same type of `app`"))
+
+(defprotocol Monad
+  "The Monad abstraction."
+  (-mreturn [m v])
+  (-mbind [m mv f]))
+
+(defprotocol Contextual
+  "Abstraction that establishes a concrete type as a member of a context.
+
+  A great example is the Maybe monad type Just. It implements
+  this abstraction to establish that Just is part of
+  the Maybe monad."
+  (-get-context [_] "Get the context associated with the type."))
+
+(defprotocol Extract
+  "A type class to extract the
+  value from a monad context."
+  (-extract [mv] "Extract the value from monad context."))
+
+(defprotocol Printable
+  "An abstraction to make a type printable in a platform
+  independent manner."
+  (-repr ^String [_] "Get the repl ready representation of the object."))
+
+(defprotocol MonadState
+  "A specific case of Monad abstraction for
+  work with state in pure functional way."
+  (-get-state [m] "Return the current state.")
+  (-put-state [m newstate] "Update the state.")
+  (-swap-state [m f] "Apply a function to the current state and update it."))