47 lines
1.3 KiB
OCaml
47 lines
1.3 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Auxiliaries for the parser. *)
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open Syntax
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let regexp_for_string s =
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let l = String.length s in
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if l = 0 then
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Epsilon
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else begin
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let re = ref(Characters [String.get s (l - 1)]) in
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for i = l - 2 downto 0 do
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re := Sequence(Characters [String.get s i], !re)
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done;
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!re
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end
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let char_class c1 c2 =
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let cl = ref [] in
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for i = Char.code c2 downto Char.code c1 do
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cl := Char.chr i :: !cl
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done;
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!cl
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let all_chars = char_class '\001' '\255'
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let rec subtract l1 l2 =
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match l1 with
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[] -> []
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