From e4938284cef9e4048528839d29e5930b0e1928f4 Mon Sep 17 00:00:00 2001
From: Stefan Israelsson Tampe <stefan.itampe@gmail.com>
Date: Mon, 9 Oct 2017 21:40:34 +0200
Subject: reversed

---
 modules/language/python/for.scm           |   5 --
 modules/language/python/list.scm          | 103 +++++++++++++++++++++++++-----
 modules/language/python/module/python.scm |   6 +-
 3 files changed, 90 insertions(+), 24 deletions(-)

(limited to 'modules')

diff --git a/modules/language/python/for.scm b/modules/language/python/for.scm
index f9cdd1e..cbbbbea 100644
--- a/modules/language/python/for.scm
+++ b/modules/language/python/for.scm
@@ -101,11 +101,6 @@
 (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)
diff --git a/modules/language/python/list.scm b/modules/language/python/list.scm
index 36d15e9..b0111c1 100644
--- a/modules/language/python/list.scm
+++ b/modules/language/python/list.scm
@@ -16,8 +16,8 @@
             pylist-pop! pylist-count pylist-extend! len in
             pylist-insert! pylist-remove! pylist-sort!
             pylist-index pylist-null pylist-delete!
-            pylist pylist-listing
-            py-all py-any))
+            pylist pylist-listing py-reversed
+            py-all py-any py-reversed))
 
 (define scm-list list)
 
@@ -40,7 +40,6 @@
     (slot-set! o 'vec (make-vector 0))
     (slot-set! o 'n   0)
     o))
-        
 
 (define-method (py-hash (o <py-list>))
   (let ((n (min complexity (slot-ref o 'n)))
@@ -145,7 +144,7 @@
 (defpair (pylist-set! o n val)
   (list-set! o n val))
 
-(defpair (pylist-set! o n val)
+(define-method (pylist-set! (o <vector>) n val)
   (vector-set! o n val))
 
 (define-method (pylist-set! (o <p>) n val)
@@ -180,6 +179,7 @@
         (to-list
          (pylist-slice (to-pylist o) n1 n2 n3)))))
 
+
 (defpair (pylist-slice o n1 n2 n3)
   (to-list
    (pylist-slice (to-pylist o) n1 n2 n3)))
@@ -472,14 +472,16 @@
 (define-method (equal? o1             (o2 <py-list>)) #f)
 
 
-(define-class <py-list-iter> (<py-list>) i)
-(define-class <string-iter> () str i)
+(define-class <py-seq-iter>  () o i n d)
+(define-class <py-list-iter> (<py-list>) i d)
+(define-class <string-iter> () str i d)
 
 ;;WRAP-IN
 (define-method (wrap-in (s <string>))
   (let ((out (make <string-iter>)))
     (slot-set! out 'str s)
     (slot-set! out 'i   0)
+    (slot-set! out 'd   1)
     out))
 
 (define-method (wrap-in (o <py-list>))
@@ -487,29 +489,95 @@
     (slot-set! out 'n   (slot-ref o 'n  ))
     (slot-set! out 'vec (slot-ref o 'vec))
     (slot-set! out 'i   0)
+    (slot-set! out 'd   1)
+    out))
+
+(define-method (py-reversed (o <py-list>))
+  (let ((out (make <py-list-iter>)))
+    (slot-set! out 'i   (- (slot-ref o 'n) 1))
+    (slot-set! out 'vec (slot-ref o 'vec))
+    (slot-set! out 'n   0)
+    (slot-set! out 'd   -1)
     out))
 
+(define-method (py-reversed (s <string>))
+  (let ((out (make <string-iter>)))
+    (slot-set! out 'str s)
+    (slot-set! out 'i   0)
+    (slot-set! out 'd   -1)
+    out))
+
+(define-method (py-reversed (o <p>))
+  (aif it (ref o '__reversed__)
+       it
+       (let ((a (ref o '__getitem__))
+             (n (ref o '__len__)))
+         (if (and a n)
+             (let ((ret (make <py-seq-iter>)))
+               (slot-set! ret 'o a)
+               (slot-set! ret 'i (n))
+               (slot-set! ret 'n -1)
+               (slot-set! ret 'd -1))
+             (next-method)))))
+
+(define-method (wrap-in (o <p>))
+  (aif it (ref o '__iter__)
+       it
+       (let ((a (ref o '__getitem__)))
+         (if a
+             (let ((ret (make <py-seq-iter>)))
+               (slot-set! ret 'o a)
+               (slot-set! ret 'i 0)
+               (slot-set! ret 'n -1)
+               (slot-set! ret 'd 1))
+             (next-method)))))
+
+
 (define-method (wrap-in (o <py-list-iter>)) o)
 (define-method (wrap-in (o <string-iter> )) o)
+(define-method (wrap-in (o <py-seq-iter> )) o)
+
 ;;NEXT
+(define-method (next (o <py-seq-iter>))
+  (let ((i (slot-ref o 'i))
+        (d (slot-ref o 'd))
+        (a (slot-ref o 'a)))
+    (let ((r (a i)))
+      (slot-set! o 'i (+ i d))
+      r)))
+        
 (define-method (next (o <string-iter>))
   (let ((i   (slot-ref o 'i  ))
+        (d   (slot-ref o 'd))
         (str (slot-ref o 'str)))
-    (if (< i (string-length str))
-        (let ((ret (string-ref str i)))
-          (slot-set! o 'i (+ i 1))
-          (list->string (scm-list ret)))
-        (throw StopIteration))))
+    (if (> d 0)
+        (if (< i (string-length str))
+            (let ((ret (string-ref str i)))
+              (slot-set! o 'i (+ i d))
+              (list->string (scm-list ret)))
+            (throw StopIteration))
+        (if (>= i 0)
+            (let ((ret (string-ref str i)))
+              (slot-set! o 'i (+ i d))
+              (list->string (scm-list ret)))
+            (throw StopIteration)))))
 
 (define-method (next (o <py-list-iter>))
   (let ((i   (slot-ref o 'i  ))
+        (d   (slot-ref o 'd))
         (n   (slot-ref o 'n  ))
         (vec (slot-ref o 'vec)))
-    (if (< i n)
-        (let ((ret (vector-ref vec i)))
-          (slot-set! o 'i (+ i 1))
-          ret)
-        (throw StopIteration))))
+    (if (> d 0)
+        (if (< i n)
+            (let ((ret (vector-ref vec i)))
+              (slot-set! o 'i (+ i 1))
+              ret)
+            (throw StopIteration))
+        (if (>= i n)
+            (let ((ret (vector-ref vec i)))
+              (slot-set! o 'i (- i 1))
+              ret)
+            (throw StopIteration)))))
   
 ;;INSERT
 (define-method (pylist-insert! (o <py-list>) i val)
@@ -645,7 +713,8 @@
        (next-method)))
 
 
-#:len
+;; len
+
 
 (defpair (len l)  (length l))
 (define-method (len (v <vector>))  (vector-length v))
diff --git a/modules/language/python/module/python.scm b/modules/language/python/module/python.scm
index c391907..0dab709 100644
--- a/modules/language/python/module/python.scm
+++ b/modules/language/python/module/python.scm
@@ -27,9 +27,10 @@
   #:re-export (Exception StopIteration send sendException next
                          GeneratorExit sendClose RuntimeError
                          len dir next dict None property range
-			 tuple)
+                         tuple
+			 )
   #:export (print repr complex float int round
-                  set all any bin callable
+                  set all any bin callable reversed
                   chr classmethod staticmethod
                   divmod enumerate filter format
                   getattr hasattr hex isinstance
@@ -200,3 +201,4 @@
 (define min  py-min)
 (define max  py-max)
 (define list pylist)
+(define reversed py-reversed)
-- 
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