Add all the A tasks

2013-04-10 14:58:50 -07:00 · 2013-04-10 14:58:50 -07:00 · 051504d65b
commit 051504d65b
parent 2dd7375f96
1608 changed files with 18584 additions and 0 deletions
--- a/Task/Arithmetic-evaluation/PicoLisp/arithmetic-evaluation-1.l
+++ b/Task/Arithmetic-evaluation/PicoLisp/arithmetic-evaluation-1.l
@ -0,0 +1,23 @@
+(de ast (Str)
+   (let *L (str Str "")
+      (aggregate) ) )
+
+(de aggregate ()
+   (let X (product)
+      (while (member (car *L) '("+" "-"))
+         (setq X (list (intern (pop '*L)) X (product))) )
+      X ) )
+
+(de product ()
+   (let X (term)
+      (while (member (car *L) '("*" "/"))
+         (setq X (list (intern (pop '*L)) X (term))) )
+      X ) )
+
+(de term ()
+   (let X (pop '*L)
+      (cond
+         ((num? X) X)
+         ((= "+" X) (term))
+         ((= "-" X) (list '- (term)))
+         ((= "(" X) (prog1 (aggregate) (pop '*L)))) ) ) )