1 files changed, 51 insertions, 0 deletions
diff --git a/tools/coqdoc/alpha.ml b/tools/coqdoc/alpha.ml
new file mode 100644
index 0000000000..36ce405fe6
--- /dev/null
+++ b/tools/coqdoc/alpha.ml
@@ -0,0 +1,51 @@
+(************************************************************************)
+(*         *   The Coq Proof Assistant / The Coq Development Team       *)
+(*  v      *   INRIA, CNRS and contributors - Copyright 1999-2018       *)
+(* <O___,, *       (see CREDITS file for the list of authors)           *)
+(*   \VV/  **************************************************************)
+(*    //   *    This file is distributed under the terms of the         *)
+(*         *     GNU Lesser General Public License Version 2.1          *)
+(*         *     (see LICENSE file for the text of the license)         *)
+(************************************************************************)
+
+open Cdglobals
+
+let norm_char_latin1 c = match Char.uppercase_ascii c with
+  | '\192'..'\198' -> 'A'
+  | '\199' -> 'C'
+  | '\200'..'\203' -> 'E'
+  | '\204'..'\207' -> 'I'
+  | '\209' -> 'N'
+  | '\210'..'\214' -> 'O'
+  | '\217'..'\220' -> 'U'
+  | '\221' -> 'Y'
+  | c -> c
+
+let norm_char_utf8 c = Char.uppercase_ascii c
+
+let norm_char c =
+  if !utf8 then norm_char_utf8 c else
+  if !latin1 then norm_char_latin1 c else
+  Char.uppercase_ascii c
+
+let norm_string = String.map (fun s -> norm_char s)
+
+let compare_char c1 c2 = match norm_char c1, norm_char c2 with
+  | ('A'..'Z' as c1), ('A'..'Z' as c2) -> compare c1 c2
+  | 'A'..'Z', _ -> -1
+  | _, 'A'..'Z' -> 1
+  | '_', _ -> -1
+  | _, '_' -> 1
+  | c1, c2 -> compare c1 c2
+
+let compare_string s1 s2 =
+  let n1 = String.length s1 in
+  let n2 = String.length s2 in
+  let rec cmp i =
+    if i == n1 || i == n2 then
+      n1 - n2
+    else
+      let c = compare_char s1.[i] s2.[i] in
+      if c == 0 then cmp (succ i) else c
+  in
+  cmp 0