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authorJörg Frings-Fürst <debian@jff-webhosting.net>2015-04-03 13:14:53 +0200
committerJörg Frings-Fürst <debian@jff-webhosting.net>2015-04-03 13:14:53 +0200
commitc43dfb815a4951b8248f4f0e98babe4f80204f03 (patch)
tree82745ed2353757c41ea1865bad9ac7a1b0a8a366 /src/NaturalCollate.vala
parent2785a691b958a79a1dd606c445188c71c3f58b3c (diff)
Imported Upstream version 0.22.0upstream/0.22.0
Diffstat (limited to 'src/NaturalCollate.vala')
-rw-r--r--src/NaturalCollate.vala98
1 files changed, 98 insertions, 0 deletions
diff --git a/src/NaturalCollate.vala b/src/NaturalCollate.vala
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+/**
+ * NaturalCollate
+ * Simple helper class for natural sorting in Vala.
+ *
+ * (c) Tobia Tesan <tobia.tesan@gmail.com>, 2014
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the Lesser GNU General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the License, or (at your option) any later version.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; see the file COPYING. If not,
+ * see <http://www.gnu.org/licenses/>.
+ */
+
+namespace NaturalCollate {
+
+private const unichar SUPERDIGIT = ':';
+private const unichar NUM_SENTINEL = 0x2; // glib uses these, so do we
+private const string COLLATION_SENTINEL = "\x01\x01\x01";
+
+private static int read_number(owned string s, ref int byte_index) {
+ /*
+ * Given a string in the form [numerals]*[everythingelse]*
+ * returns the int value of the first block and increments index
+ * by its length as a side effect.
+ * Notice that "numerals" is not just 0-9 but everything else
+ * Unicode considers a numeral (see: string::isdigit())
+ */
+ int number = 0;
+
+ while (s.length != 0 && s.get_char(0).isdigit()) {
+ number = number*10;
+ number += s.get_char(0).digit_value();
+ int second_char = s.index_of_nth_char(1);
+ s = s.substring(second_char);
+ byte_index += second_char;
+ }
+ return number;
+}
+
+public static int compare(string str1, string str2) {
+ return strcmp(collate_key(str1), collate_key(str2));
+}
+
+public static string collate_key(owned string str) {
+ /*
+ * Computes a collate key.
+ * Has roughly the same effect as g_utf8_collate_key_for_file, except that it doesn't
+ * handle the dot as a special char.
+ */
+ assert (str.validate());
+ string result = "";
+ bool eos = (str.length == 0);
+
+ while (!eos) {
+ assert(str.validate());
+ int position = 0;
+ while (!(str.get_char(position).to_string() in "0123456789")) {
+ // We only care about plain old 0123456789, aping what g_utf8_collate_key_for_filename does
+ position++;
+ }
+
+ // (0... position( is a bunch of non-numerical chars, so we compute and append the collate key...
+ result = result + (str.substring(0, position).collate_key());
+
+ // ...then throw them away
+ str = str.substring(position);
+
+ eos = (str.length == 0);
+ position = 0;
+
+ if (!eos) {
+ // We have some numbers to handle in front of us
+ int number = read_number(str, ref position);
+ str = str.substring(position);
+ int number_of_superdigits = number.to_string().length;
+ string to_append = "";
+ for (int i = 1; i < number_of_superdigits; i++) {
+ // We append n - 1 superdigits where n is the number of digits
+ to_append = to_append + SUPERDIGIT.to_string();
+ }
+ to_append = to_append + (number.to_string()); // We append the actual number
+ result = result +
+ COLLATION_SENTINEL +
+ NUM_SENTINEL.to_string() +
+ to_append;
+ }
+ eos = (str.length == 0);
+ }
+
+ result = result + NUM_SENTINEL.to_string();
+ // No specific reason except that glib does it
+
+ return result;
+}
+}