1 files changed, 59 insertions, 1 deletions
diff --git a/modules/language/python/for.scm b/modules/language/python/for.scm
index 47f6992..f23ce6e 100644
--- a/modules/language/python/for.scm
+++ b/modules/language/python/for.scm
@@ -1,7 +1,12 @@
 (define-module (language python for)
+  #:use-module (language python yield)
   #:use-module (oop pf-objects)
+  #:use-module (language python exceptions)
+  #:use-module (oop goops)
   #:use-module (ice-9 control)
-  #:export (for break))
+  #:export (for break next write))
+
+(define-syntax-rule (aif it p x y) (let ((it p)) (if it x y)))
 
 (eval-when (compile eval load)
   (define (generate-temporaries2 x)
@@ -129,6 +134,59 @@
                    (lambda q (values)))))))))))
 
 
+(define-class <scm-list>   () l)
+(define-class <scm-string> () s i)
+  
+(define-method (next (l <scm-list>))
+  (let ((ll (slot-ref l 'l)))
+    (if (pair? ll)
+        (begin
+          (slot-set! l 'l (cdr ll))
+          (car ll))
+        (throw StopIteration))))
+
+(define-method (next (l <scm-string>))
+  (let ((s (slot-ref l 's))
+        (i (slot-ref l 'i)))
+    (if (= i (string-length s))
+        (throw StopIteration)
+        (begin
+          (slot-set! l 'i (+ i 1))
+          (string-ref s i)))))
+
+(define-method (next (l <yield>))
+  (let ((k (slot-ref l 'k))
+        (s (slot-ref l 's)))
+    (if k
+        (k (lambda () 'None))
+        (s))))
+
+
+(define-method (next (l <p>))
+  ((ref l '__next__)))
+
+(define-method (wrap-in  (x <p>))
+  (aif it (ref x '__iter__ #f)
+       (it)
+       x))
+
+(define-method (wrap-in x)
+  (cond
+   ((pair? x)
+    (let ((o (make <scm-list>)))
+      (slot-set! o 'l x)
+      o))
+   
+   ((string? x)
+    (let ((o (make <scm-string>)))
+      (slot-set! o 's x)
+      (slot-set! o 'i 0)
+      o))
+   
+   (else
+    x)))
+
+
 #;
 (pk
  (for c ((x : (gen '(1 2 3)))) ((s 0))