+; Copyright 2008 (c) Meikel Brandmeyer.
+; Permission is hereby granted, free of charge, to any person obtaining a copy
+; of this software and associated documentation files (the "Software"), to deal
+; in the Software without restriction, including without limitation the rights
+; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+; copies of the Software, and to permit persons to whom the Software is
+; furnished to do so, subject to the following conditions:
+; The above copyright notice and this permission notice shall be included in
+; all copies or substantial portions of the Software.
+; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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+; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ `monad` is a small support library for Clojure_ which provides some of
+ the infrastructure to handle monads. A monad is defined as a `struct-map`
+ which contains the key `:monad`, which defines the type of the actual
+ monad. This value is used as the dispatch value for the `bind` multimethod.
+ `bind` is obviously dependent on the actual monad implementation.
+ On application of monads are for example the parser combinators. Here
+ the monads server as means to combine different parsers together to form
+ new parsers. An example implementation for Clojure_ is „Parser_“ from the
+ .. _Clojure: http://clojure.org
+ .. _Parser: http://kotka.de/projects/clojure/parser.html")
+ `monad-structure` defines the basic structure of the monad supporting
+ structure. The :monad key is the dispatch value for the `bind` multimethod.
+ Whatever else is contained in the structure is completely up to the actual
+ implementation and will not be touched by the functions of the monad library."}
+ (create-struct :monad))
+ (bind monad (fn [result] ...)) : Monad a -> (a -> b)-> Monad b
+ `bind` makes the value of the given monad available to a function.
+ The function may act on the value, but it must return another monad.
+ (Although this cannot be enforced in Clojure."}
+ bind (fn [m f] (:monad m)))
+ `let-bind` binds the result of the given monads to the given variables
+ and executes the body in an implicit `do` block. How this done exactly
+ depends on the actual monad. The `let-bind` body should again return a
+ (let [[var monad & clauses] clauses]
+ `(bind ~monad (fn [~var] ~@body))
+ `(bind ~monad (fn [~var] (let-bind ~clauses ~@body))))))