1 files changed, 96 insertions, 0 deletions
diff --git a/lib/unistring/uninorm/composition.c b/lib/unistring/uninorm/composition.c
new file mode 100644
index 0000000..d08ec84
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+++ b/lib/unistring/uninorm/composition.c
@@ -0,0 +1,96 @@
+/* Canonical composition of Unicode characters.
+   Copyright (C) 2002, 2006, 2009, 2011-2021 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2009.
+
+   This program is free software: you can redistribute it and/or
+   modify it under the terms of either:
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at your
+       option) any later version.
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at your
+       option) any later version.
+
+   or both in parallel, as here.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "uninorm.h"
+
+#include <string.h>
+
+struct composition_rule { char codes[6]; unsigned int combined; };
+
+#include "composition-table.h"
+
+ucs4_t
+uc_composition (ucs4_t uc1, ucs4_t uc2)
+{
+  if (uc1 < 0x12000 && uc2 < 0x12000)
+    {
+      if (uc2 >= 0x1161 && uc2 < 0x1161 + 21
+          && uc1 >= 0x1100 && uc1 < 0x1100 + 19)
+        {
+          /* Hangul: Combine single letter L and single letter V to form
+             two-letter syllable LV.  */
+          return 0xAC00 + ((uc1 - 0x1100) * 21 + (uc2 - 0x1161)) * 28;
+        }
+      else if (uc2 > 0x11A7 && uc2 < 0x11A7 + 28
+               && uc1 >= 0xAC00 && uc1 < 0xD7A4 && ((uc1 - 0xAC00) % 28) == 0)
+        {
+          /* Hangul: Combine two-letter syllable LV with single-letter T
+             to form three-letter syllable LVT.  */
+          return uc1 + (uc2 - 0x11A7);
+        }
+      else
+        {
+#if 0
+          unsigned int uc = MUL1 * uc1 * MUL2 * uc2;
+          unsigned int index1 = uc >> composition_header_0;
+          if (index1 < composition_header_1)
+            {
+              int lookup1 = u_composition.level1[index1];
+              if (lookup1 >= 0)
+                {
+                  unsigned int index2 = (uc >> composition_header_2) & composition_header_3;
+                  int lookup2 = u_composition.level2[lookup1 + index2];
+                  if (lookup2 >= 0)
+                    {
+                      unsigned int index3 = (uc & composition_header_4);
+                      unsigned int lookup3 = u_composition.level3[lookup2 + index3];
+                      if ((lookup3 >> 16) == uc2)
+                        return lookup3 & ((1U << 16) - 1);
+                    }
+                }
+            }
+#else
+          char codes[6];
+          const struct composition_rule *rule;
+
+          codes[0] = (uc1 >> 16) & 0xff;
+          codes[1] = (uc1 >> 8) & 0xff;
+          codes[2] = uc1 & 0xff;
+          codes[3] = (uc2 >> 16) & 0xff;
+          codes[4] = (uc2 >> 8) & 0xff;
+          codes[5] = uc2 & 0xff;
+
+          rule = gl_uninorm_compose_lookup (codes, 6);
+          if (rule != NULL)
+            return rule->combined;
+#endif
+        }
+    }
+  return 0;
+}