53 lines
1.1 KiB
OCaml
53 lines
1.1 KiB
OCaml
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type _ typ =
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| Int : int -> int typ
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| Unit : unit typ
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let typ_to_string : type a. a typ -> string = function
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| Int n -> Printf.sprintf "%d" n
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| Unit -> "()"
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type (_, _) binop =
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| Add : (int, int) binop
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| Sub : (int, int) binop
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| Mul : (int, int) binop
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| Div : (int, int) binop
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let binop_to_string : type a b. (a, b) binop -> string = function
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| Add -> "+"
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| Sub -> "-"
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| Mul -> "*"
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| Div -> "/"
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type _ t =
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| Value : 'a typ -> 'a t
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| Binop : 'a t * ('a, 'b) binop * 'a t -> 'b t
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| Set_binop_pre : ('a, 'b) binop * int t -> unit t
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let value v = Value v
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let binop left op right =
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Binop (left, op, right)
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let set_binop_pre op pre =
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Set_binop_pre (op, pre)
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(* print ast LISP style. *)
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let print ast =
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let pr = Printf.printf in
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let pv v = pr "%s" @@ typ_to_string v in
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let rec aux : type a. a t -> unit = function
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| Value n -> pv n
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| Binop (left, op, right) -> begin
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pr "(%s " @@ binop_to_string op;
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aux left;
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pr " ";
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aux right;
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pr ")";
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end
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| Set_binop_pre (op, pre) ->
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pr "(set_pre %s " (binop_to_string op);
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aux pre;
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pr ")"
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in
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aux ast; pr "\n"
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