Rename REAMDE to README.md

[nit.git] / lib / counter.nit

diff --git a/lib/counter.nit b/lib/counter.nit
index 6545b73..befce9c 100644 (file)
--- a/lib/counter.nit
+++ b/lib/counter.nit
@@ -53,14 +53,14 @@ class Counter[E]
        redef fun iterator do return map.iterator
 
        # The number of counted occurrences of `e`
-       redef fun [](e: E): Int
+       redef fun [](e)
        do
                var map = self.map
                if map.has_key(e) then return map[e]
                return 0
        end
 
-       redef fun []=(e: E, value: Int)
+       redef fun []=(e, value)
        do
                sum -= self[e]
                self.map[e] = value
@@ -93,6 +93,22 @@ class Counter[E]
                for e in es do inc(e)
        end
 
+       # Decrement the value of `e` by 1
+       fun dec(e: E) do
+               if not has_key(e) then
+                       self.map[e] = 0
+               else
+                       self.map[e] = self[e] - 1
+                       sum += - 1
+               end
+       end
+
+       # Decrement the value for each element of `es`
+       fun dec_all(es: Collection[E])
+       do
+               for e in es do dec(e)
+       end
+
        # A new Counter initialized with `inc_all`.
        init from(es: Collection[E])
        do