From f66c95d8da7fcad29f0faf4a1aa910b9fddcf1a3 Mon Sep 17 00:00:00 2001
From: Julien Lengrand-Lambert <julien@lengrand.fr>
Date: Sat, 23 Nov 2013 18:06:43 +0100
Subject: [PATCH] Starts implementing add method of version with collisions.

---
 02_hash_maps/hm.py      | 22 +++++++++++++++++++++-
 02_hash_maps/hm_test.py | 12 ++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/02_hash_maps/hm.py b/02_hash_maps/hm.py
index a236ce6..7c405a5 100644
--- a/02_hash_maps/hm.py
+++ b/02_hash_maps/hm.py
@@ -55,4 +55,24 @@ class HashMap():
 			
 		return h % self._hash_size
 
-	
+class HMTableCollision(HashMap):
+	"""
+	Extension of the previous HashMap implementation that takes care of
+	collisions.
+	Instead of having only one slot available per index in the table, 
+	each index will contain a list. This means several elements can be 
+	stored with the same index.
+	"""
+	def add(self, key, value):
+			"""
+			Adds the provided value to the hashmap.
+			Raises an Exception if a collision is detected
+			"""
+			my_key = self._hash(key)
+			
+			
+			if self.hmap[my_key] == None:
+				self.hmap[my_key] = value
+				self._size += 1
+			else: 
+				raise Exception("Collision detected at index %d", key)
diff --git a/02_hash_maps/hm_test.py b/02_hash_maps/hm_test.py
index 26b151b..21f1e8a 100644
--- a/02_hash_maps/hm_test.py
+++ b/02_hash_maps/hm_test.py
@@ -5,9 +5,21 @@ Unit tests for the Hash Map table implementation
 """
 
 from hm import HashMap
+from hm import HMTableCollision
 
 import unittest
 
+class test_hash_map_table_collision(unittest.TestCase):
+	
+	def test_add(self):
+		hm = HMTableCollision()
+		
+		hm.add("a", "Ibiza")
+		self.assertEqual(hm.size(), 1)
+
+		# Tests Collision
+		self.assertRaises(Exception, lambda x : hm.add("a", "Ibiza"))
+		self.assertEqual(hm.size(), 1)
 
 class test_hash_map(unittest.TestCase):