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-rw-r--r--src/basic/gunicode.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/src/basic/gunicode.c b/src/basic/gunicode.c
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+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/* gunicode.c - Unicode manipulation functions
+ *
+ * Copyright (C) 1999, 2000 Tom Tromey
+ * Copyright © 2000, 2005 Red Hat, Inc.
+ */
+
+#include "gunicode.h"
+
+#define unichar uint32_t
+
+/**
+ * g_utf8_prev_char:
+ * @p: a pointer to a position within a UTF-8 encoded string
+ *
+ * Finds the previous UTF-8 character in the string before @p.
+ *
+ * @p does not have to be at the beginning of a UTF-8 character. No check
+ * is made to see if the character found is actually valid other than
+ * it starts with an appropriate byte. If @p might be the first
+ * character of the string, you must use g_utf8_find_prev_char() instead.
+ *
+ * Return value: a pointer to the found character.
+ **/
+char *
+utf8_prev_char (const char *p)
+{
+ for (;;)
+ {
+ p--;
+ if ((*p & 0xc0) != 0x80)
+ return (char *)p;
+ }
+}
+
+struct Interval
+{
+ unichar start, end;
+};
+
+static int
+interval_compare (const void *key, const void *elt)
+{
+ unichar c = (unichar) (long) (key);
+ struct Interval *interval = (struct Interval *)elt;
+
+ if (c < interval->start)
+ return -1;
+ if (c > interval->end)
+ return +1;
+
+ return 0;
+}
+
+/*
+ * NOTE:
+ *
+ * The tables for g_unichar_iswide() and g_unichar_iswide_cjk() are
+ * generated from the Unicode Character Database's file
+ * extracted/DerivedEastAsianWidth.txt using the gen-iswide-table.py
+ * in this way:
+ *
+ * ./gen-iswide-table.py < path/to/ucd/extracted/DerivedEastAsianWidth.txt | fmt
+ *
+ * Last update for Unicode 6.0.
+ */
+
+/**
+ * g_unichar_iswide:
+ * @c: a Unicode character
+ *
+ * Determines if a character is typically rendered in a double-width
+ * cell.
+ *
+ * Return value: %TRUE if the character is wide
+ **/
+bool
+unichar_iswide (unichar c)
+{
+ /* See NOTE earlier for how to update this table. */
+ static const struct Interval wide[] = {
+ {0x1100, 0x115F}, {0x2329, 0x232A}, {0x2E80, 0x2E99}, {0x2E9B, 0x2EF3},
+ {0x2F00, 0x2FD5}, {0x2FF0, 0x2FFB}, {0x3000, 0x303E}, {0x3041, 0x3096},
+ {0x3099, 0x30FF}, {0x3105, 0x312D}, {0x3131, 0x318E}, {0x3190, 0x31BA},
+ {0x31C0, 0x31E3}, {0x31F0, 0x321E}, {0x3220, 0x3247}, {0x3250, 0x32FE},
+ {0x3300, 0x4DBF}, {0x4E00, 0xA48C}, {0xA490, 0xA4C6}, {0xA960, 0xA97C},
+ {0xAC00, 0xD7A3}, {0xF900, 0xFAFF}, {0xFE10, 0xFE19}, {0xFE30, 0xFE52},
+ {0xFE54, 0xFE66}, {0xFE68, 0xFE6B}, {0xFF01, 0xFF60}, {0xFFE0, 0xFFE6},
+ {0x1B000, 0x1B001}, {0x1F200, 0x1F202}, {0x1F210, 0x1F23A},
+ {0x1F240, 0x1F248}, {0x1F250, 0x1F251},
+ {0x1F300, 0x1F567}, /* Miscellaneous Symbols and Pictographs */
+ {0x20000, 0x2FFFD}, {0x30000, 0x3FFFD},
+ };
+
+ if (bsearch ((void *)(uintptr_t)c, wide, (sizeof (wide) / sizeof ((wide)[0])), sizeof wide[0],
+ interval_compare))
+ return true;
+
+ return false;
+}
+
+const char utf8_skip_data[256] = {
+ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+ 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1
+};