Initial data commit

Task/Sort-three-variables/TXR/sort-three-variables.txr

@@ -0,0 +1,50 @@
+(defmacro sort-places (. places)
+  (caseql (len places)
+    ((0 1) nil)
+    (2 (with-gensyms (p0 p1)
+         ^(placelet ((p0 (read-once ,[places 0]))
+                     (p1 (read-once ,[places 1])))
+            (if (greater p0 p1)
+              (swap p0 p1)))))
+    (3 (with-gensyms (p0 p1 p2)
+         ^(placelet ((p0 (read-once ,[places 0]))
+                     (p1 (read-once ,[places 1]))
+                     (p2 (read-once ,[places 2])))
+            (if (greater p0 p1)
+              (swap p0 p1))
+            (if (greater p1 p2)
+              (swap p1 p2))
+            (if (greater p0 p1)
+              (swap p0 p1)))))
+    (t (let ((gens [mapcar (ret (gensym)) places]))
+         (with-gensyms (vec)
+           ^(placelet ,(zip gens places)
+              (let ((,vec (vec ,*gens)))
+                (nsort ,vec)
+                (set ,*(append-each ((g gens)
+                                     (i 0))
+                         ^(,g [,vec ,i]))))))))))
+
+(prinl (sort-places))
+
+(let ((x 1))
+  (sort-places x)
+  (prinl x))
+
+(let ((x 2)
+      (y 1))
+  (sort-places x y)
+  (prinl (list x y)))
+
+(let ((a 3)
+      (b 2)
+      (c 1))
+  (sort-places a b c)
+  (prinl (list a b c)))
+
+(let ((a 4)
+      (b 3)
+      (c 2)
+      (d 1))
+  (sort-places a b c d)
+  (prinl (list a b c d)))