blob: bc9858a29276a739531d8f3d612f5d955239a3c7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
## Copyright (c) Eduardo Julian. All rights reserved.
## The use and distribution terms for this software are covered by the
## Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
## which can be found in the file epl-v10.html at the root of this distribution.
## By using this software in any fashion, you are agreeing to be bound by
## the terms of this license.
## You must not remove this notice, or any other, from this software.
(;import lux
(lux/control (functor #as F #refer #all)
(monad #as M #refer #all)))
## [Types]
(deftype #export (State s a)
(-> s (, s a)))
## [Structures]
(defstruct #export State/Functor (Functor State)
(def (F;map f ma)
(lambda [state]
(let [[state' a] (ma state)]
[state' (f a)]))))
(defstruct #export State/Monad (All [s]
(Monad (State s)))
(def M;_functor State/Functor)
(def (M;wrap x)
(lambda [state]
[state x]))
(def (M;join mma)
(lambda [state]
(let [[state' ma] (mma state)]
(ma state')))))
|
