24 lines
588 B
OCaml
24 lines
588 B
OCaml
open Ast
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let arith f a b =
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match a, b with
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| Int a, Int b -> Int (f a b)
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| _ -> failwith "typecheck failed"
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let binop_to_func = function
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| Add -> arith Int.add
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| Sub -> arith Int.sub
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| Mul -> arith Int.mul
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| Div -> arith Int.div
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let rec eval = function
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| Value v -> v
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| Binop (l, op, r) ->
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let f = binop_to_func op in
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f (eval l) (eval r)
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| Set_binop_pre (op, l) ->
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let l = match eval l with Int n -> n | _ -> failwith "not int" in
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Hashtbl.replace Parser.precedence op l;
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Unit
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| Get_binop_pre op ->
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Int (Hashtbl.find Parser.precedence op)
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