Initial data commit

Task/Hash-join/11l/hash-join.11l

@@ -0,0 +1,24 @@
+F hash_join(table1, table2)
+   DefaultDict[String, [(Int, String)]] h
+   L(s) table1
+      h[s[1]].append(s)
+
+   [((Int, String), (String, String))] res
+   L(r) table2
+      L(s) h[r[0]]
+         res [+]= (s, r)
+   R res
+
+V table1 = [(27, ‘Jonah’),
+            (18, ‘Alan’),
+            (28, ‘Glory’),
+            (18, ‘Popeye’),
+            (28, ‘Alan’)]
+V table2 = [(‘Jonah’, ‘Whales’),
+            (‘Jonah’, ‘Spiders’),
+            (‘Alan’, ‘Ghosts’),
+            (‘Alan’, ‘Zombies’),
+            (‘Glory’, ‘Buffy’)]
+
+L(row) hash_join(table1, table2)
+   print(row)