Initial data commit

Task/Parsing-RPN-calculator-algorithm/Ela/parsing-rpn-calculator-algorithm.ela

@@ -0,0 +1,42 @@
+open string generic monad io
+
+type OpType = Push | Operate
+  deriving Show
+
+type Op = Op (OpType typ) input stack
+  deriving Show
+
+parse str = split " " str
+
+eval stack []      = []
+eval stack (x::xs) = op :: eval nst xs
+  where (op, nst)  = conv x stack
+        conv "+"@x = operate x (+)
+        conv "-"@x = operate x (-)
+        conv "*"@x = operate x (*)
+        conv "/"@x = operate x (/)
+        conv "^"@x = operate x (**)
+        conv x     = \stack ->
+          let n = gread x::stack in
+          (Op Push x n, n)
+        operate input fn (x::y::ys) =
+          let n = (y `fn` x) :: ys in
+          (Op Operate input n, n)
+
+print_line (Op typ input stack) = do
+  putStr input
+  putStr "\t"
+  put typ
+  putStr "\t\t"
+  putLn stack
+
+print ((Op typ input stack)@x::xs) lv = print_line x `seq` print xs (head stack)
+print [] lv = lv
+
+print_result xs = do
+  putStrLn "Input\tOperation\tStack after"
+  res <- return $ print xs 0
+  putStrLn ("Result: " ++ show res)
+
+res = parse "3 4 2 * 1 5 - 2 3 ^ ^ / +" |> eval []
+print_result res ::: IO