adding option to decrease weight

added a new option, -d/--decrease to decrease the weight of a path.
added --increase as an alias to --add for symetry.

bin/autojump

@@ -83,7 +83,7 @@ class Database:
 
     def add(self, path, increment = 10):
         """
-        Increment existing paths or initialize new ones to 10.
+        Increase wheight of existing paths or initialize new ones to 10.
         """
         if path not in self.data:
             self.data[path] = increment
@@ -92,6 +92,15 @@ class Database:
             self.data[path] = math.sqrt((self.data[path]**2)+(increment**2))
         self.save()
 
+    def decrease(self, path, increment=10):
+        """
+        Decrease wheight of existing path. Unknown ones are ignored.
+        """
+        if path in self.data:
+            import math
+            self.data[path] = math.sqrt((self.data[path] ** 2) - (increment ** 2))
+            self.save()
+
     def decay(self):
         """
         Decay database entries.
@@ -221,8 +230,10 @@ def options():
             epilog="Please see autojump(1) man pages for full documentation.")
     parser.add_argument('directory', metavar='DIR', nargs='*', default='',
             help='directory to jump to')
-    parser.add_argument('-a', '--add', metavar='DIR',
-            help='manually add path to database')
+    parser.add_argument('-a', '--add', '--increase', metavar='DIR',
+            help='manually add path to database, or increase path weight for existing paths')
+    parser.add_argument('-d', '--decrease', metavar='DIR',
+            help='manually decrease path weight in the database')
     parser.add_argument('-b', '--bash', action="store_true", default=False,
             help='enclose directory quotes to prevent errors')
     parser.add_argument('--complete', action="store_true", default=False,
@@ -243,6 +254,12 @@ def options():
             db.add(decode(ARGS.add))
         return True
 
+    if (ARGS.decrease):
+        if(ARGS.decrease != os.path.expanduser("~")):
+            db = Database(DB_FILE)
+            db.decrease(ARGS.decrease)
+        return True
+
     if (ARGS.purge):
         db = Database(DB_FILE)
         removed = db.purge()

tests/runtests.py

@@ -53,6 +53,15 @@ class TestAutojump(unittest.TestCase):
         self.db.add('/2', 10)
         self.assertEqual(self.db.get_weight('/2'), 14.142135623730951)
 
+    def test_db_decrease(self):
+        self.db.add('/1', 100)
+        self.db.decrease('/a', 42)
+        self.assertTrue(self.db.get_weight('/a') < 100)
+        self.db.add('/2', 100)
+        self.db.add('/2', 42)
+        self.db.decrease('/2', 42)
+        self.assertEquals(self.db.get_weight('/2'), 100)
+
     def test_db_get_weight(self):
         self.assertEqual(self.db.get_weight('/'), 0)