53 lines
950 B
OCaml
53 lines
950 B
OCaml
type t =
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| Int of int
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| Float of float
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| String of string
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| Ident of string
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| Plus
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| Minus
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| Asterisk
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| Slash
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| Carret
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| Percent
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| LParen
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| RParen
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| Equal
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| Not_equal
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| Greater
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| Less
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| Greater_equal
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| Less_equal
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| Hash
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| Right_arrow
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(* list of tokens. because front tokens are detected first, longer
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* tokens must come earlier than shorter tokens. *)
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let tokens = ref [
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"->", Right_arrow;
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"<>", Not_equal;
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">=", Greater_equal;
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"<=", Less_equal;
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">", Greater;
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"<", Less;
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"+", Plus;
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"-", Minus;
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"*", Asterisk;
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"/", Slash;
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"^", Carret;
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"%", Percent;
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"(", LParen;
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")", RParen;
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"=", Equal;
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"#", Hash;
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]
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let to_string = function
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| Int n -> string_of_int n
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| Float n -> string_of_float n
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| String x -> x
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| Ident s -> s
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| t ->
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begin match List.find_opt (fun (_, tok) -> t = tok) !tokens with
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| None -> failwith "Token.to_string"
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| Some (s, _) -> s
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end
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