Initial data commit

Task/Parsing-RPN-calculator-algorithm/OCaml/parsing-rpn-calculator-algorithm.ocaml

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+(* binop : ('a -> 'a -> 'a) -> 'a list -> 'a list *)
+let binop op = function
+  | b::a::r -> (op a b)::r
+  | _ -> failwith "invalid expression"
+
+(* interp : float list -> string -> string * float list *)
+let interp s = function
+  | "+" -> "add",    binop ( +. ) s
+  | "-" -> "subtr",  binop ( -. ) s
+  | "*" -> "mult",   binop ( *. ) s
+  | "/" -> "divide", binop ( /. ) s
+  | "^" -> "exp",    binop ( ** ) s
+  | str -> "push", (float_of_string str) :: s
+
+(* interp_and_show : float list -> string -> float list *)
+let interp_and_show s inp =
+  let op,s' = interp s inp in
+  Printf.printf "%s\t%s\t" inp op;
+  List.(iter (Printf.printf "%F ") (rev s'));
+  print_newline ();
+  s'
+
+(* rpn_eval : string -> float list *)
+let rpn_eval str =
+  Printf.printf "Token\tAction\tStack\n";
+  let ss = Str.(split (regexp_string " ") str) in
+  List.fold_left interp_and_show [] ss