Implement uniq

README.md

@@ -283,6 +283,18 @@ Or using decorators:
         >>> [5, -4, 3, -2, 1] | sort(key=abs) | concat
         '1, -2, 3, -4, 5'
 
+    dedup()
+        Deduplicate values
+
+        >>> [1,1,2,2,3,3,1,2,3] | uniq | as_list
+        [1, 2, 3,]
+
+    uniq()
+        Like dedup() but only deduplicate consecutive values.
+
+        >>> [1,1,2,2,3,3,1,2,3] | uniq | as_list
+        [1, 2, 3, 1, 2, 3]
+
     reverse
         Like Python's built-in "reversed" primitive.
         >>> [1, 2, 3] | reverse | concat

pipe.py

@@ -92,15 +92,27 @@ def skip(iterable, qte):
 
 @Pipe
 def dedup(iterable):
-    """Only yield unique items. Rely on __hash__ of the item type to find duplication."""
+    """Only yield unique items. Use a set to keep track of duplicate data."""
     seen = set()
     for item in iterable:
-        if item in seen:
-            continue
-        else:
+        if item not in seen:
             seen.add(item)
             yield item
 
+@Pipe
+def uniq(iterable):
+    """Deduplicate consecutive duplicate values."""
+    iterator = iter(iterable)
+    try:
+        prev = next(iterator)
+    except StopIteration:
+        return []
+    yield prev
+    for item in iterator:
+        if item != prev:
+            yield item
+        prev = item
+
 @Pipe
 def all(iterable, pred):
     """Returns True if ALL elements in the given iterable are true for the