From: Jean Privat <jean@pryen.org>
Date: Fri, 6 Mar 2015 04:07:21 +0000 (+0700)
Subject: lib/map: document `Map.has_key` and implement it efficienlty
X-Git-Tag: v0.7.3~39^2~1
X-Git-Url: http://nitlanguage.org?ds=sidebyside

lib/map: document `Map.has_key` and implement it efficienlty

Signed-off-by: Jean Privat <jean@pryen.org>
---

diff --git a/lib/standard/collection/abstract_collection.nit b/lib/standard/collection/abstract_collection.nit
index 20d1584..d38e001 100644
--- a/lib/standard/collection/abstract_collection.nit
+++ b/lib/standard/collection/abstract_collection.nit
@@ -416,7 +416,14 @@ interface MapRead[K, V]
 		return default
 	end
 
-	# Alias for `keys.has`
+	# Is there an item associated with `key`?
+	#
+	#     var x = new HashMap[String, Int]
+	#     x["four"] = 4
+	#     assert x.has_key("four") == true
+	#     assert x.has_key("five") == false
+	#
+	# By default it is a synonymous to `keys.has` but could be redefined with a direct implementation.
 	fun has_key(key: K): Bool do return self.keys.has(key)
 
 	# Get a new iterator on the map.
@@ -987,6 +994,8 @@ interface CoupleMap[K, V]
 			return c.second
 		end
 	end
+
+	redef fun has_key(key) do return couple_at(key) != null
 end
 
 # Iterator on CoupleMap
diff --git a/lib/standard/collection/hash_collection.nit b/lib/standard/collection/hash_collection.nit
index b62d876..cdc7906 100644
--- a/lib/standard/collection/hash_collection.nit
+++ b/lib/standard/collection/hash_collection.nit
@@ -274,6 +274,7 @@ class HashMap[K, V]
 
 	redef var keys: RemovableCollection[K] = new HashMapKeys[K, V](self)
 	redef var values: RemovableCollection[V] = new HashMapValues[K, V](self)
+	redef fun has_key(k) do return node_at(k) != null
 end
 
 # View of the keys of a HashMap