2 files changed, 56 insertions, 0 deletions
diff --git a/control/monad.scm b/control/monad.scm
new file mode 100644
index 0000000..e5dc89d
--- /dev/null
+++ b/control/monad.scm
@@ -0,0 +1,39 @@
+(define-module (control monad)
+  #:use-module (control monad procedures)
+  ;; #:use-module (control monad syntax)
+  #:export (do <-)
+  ;; #:re-export (>>= do <-)
+                )
+
+(define-syntax do
+  (syntax-rules (<- let =)
+    ((_ let var = val rest ...)
+     (let ((var val)) (do rest ...)))
+    ((_ ptrn <- val rest ...)
+     (<- ptrn val rest ...))
+    ((_ a) a)
+    ((_ token rest ...)
+     (begin token (do rest ...)))))
+
+(define-syntax <-
+  (syntax-rules (just writer)
+    ((_ (just var) val rest ...)
+     (>>= val (lambda (var) rest ...)))
+    ((_ (writer var) val rest ...)
+     (>>= val (lambda (var) rest ...))))
+  
+  
+  #;
+  (lambda (x)
+    (syntax-case x (just writer)
+      ((_ (just var) val rest ...)
+       #'(>>= val (lambda (var) rest ...)))
+      ((_ (writer var) val rest ...)
+       #'(>>= val (lambda (var) rest ...)))
+      #; 
+      ((_ (left var) val rest ...)      ;
+      #'(>>= val (lambda (var) rest ...)))
+      #; 
+      ((_ (right var) val rest ...)     ;
+      #'(>>= val (lambda (var) rest ...))))))
+
diff --git a/control/monad/procedures.scm b/control/monad/procedures.scm
new file mode 100644
index 0000000..701f871
--- /dev/null
+++ b/control/monad/procedures.scm
@@ -0,0 +1,17 @@
+(define-module (control monad procedures)
+  #:use-module (oop goops)
+  #:use-module (srfi srfi-1)            ; concatenate!
+  #:export (>>=))
+
+(define-generic >>=)
+
+(define-method (>>= (this <null>)
+                    proc)
+  '())
+(define-method (>>= (this <pair>)
+                    (proc <procedure>))
+  (concatenate! (map proc this)))
+
+;; bind :: Monad m => m a -> (a -> m b) -> m b
+;; return :: Monad m => a -> m a
+;; map :: Functor f => (a -> b) -> f a -> f b