Implement decorating without parenthesis

Author: Vopaaz

checkpointing/decorator/default.py

@@ -25,10 +25,17 @@ def checkpoint(
 
         cache_pickle_protocol: the pickle protocol used by the cache to save results to the disk.
                               If None, use the global default `cache.pickle_protocol`
+
+    Optionally user can directly decorate the function with `@checkpoint` (without parenthesis),
+    this will cause the function to be passed in directly with the `directory` parameter.
     """
 
+    # If true, the `directory` is actually the decorated function
+    # and the actual `directory` is None
+    used_without_parenthesis = callable(directory)
+
     identifier = AutoFuncCallIdentifier()
-    cache = PickleFileCache(directory, cache_pickle_protocol)
+    cache = PickleFileCache(None if used_without_parenthesis else directory, cache_pickle_protocol)
     decorator = DecoratorCheckpoint(identifier, cache, on_error)
 
-    return decorator
+    return decorator(directory) if used_without_parenthesis else decorator

docs/changelog.md

@@ -1,6 +1,11 @@
 ## v1.0.x
 
-### v1.0.0
+### v1.0.1
+
+- Added support to decorate a function without parenthesis (`@checkpoint` instead of `@checkpoint()`)
+    - Thanks for the proposal in https://github.com/Vopaaz/checkpointing/issues/8
+
+### [v1.0.0](https://checkpointing.readthedocs.io/en/v1.0.0/)
 
 - Drop support for Python 3.7 to remove the pickle5 dependency
 

integtests/no-parenthesis/Readme.md

@@ -0,0 +1,2 @@
+As requested in https://github.com/Vopaaz/checkpointing/issues/8 we are introducing a new syntax
+to decorate with `checkpoint` without parenthesis.

integtests/no-parenthesis/re-executed/outputs/output0.txt

@@ -0,0 +1,2 @@
+Running
+0

integtests/no-parenthesis/re-executed/outputs/output1.txt

@@ -0,0 +1,2 @@
+Running
+1

integtests/no-parenthesis/re-executed/workspaces/workspace0/main.py

@@ -0,0 +1,9 @@
+from checkpointing import checkpoint
+
+@checkpoint
+def foo(a):
+    print("Running")
+    return a
+
+if __name__ == "__main__":
+    print(foo(0))

integtests/no-parenthesis/re-executed/workspaces/workspace1/main.py

@@ -0,0 +1,9 @@
+from checkpointing import checkpoint
+
+@checkpoint
+def foo(a):
+    print("Running")
+    return a + 1
+
+if __name__ == "__main__":
+    print(foo(0))

integtests/no-parenthesis/skipped/comment-annotation/outputs/output0.txt

@@ -0,0 +1,2 @@
+Running
+1

integtests/no-parenthesis/skipped/comment-annotation/outputs/output1.txt

@@ -0,0 +1 @@
+1

integtests/no-parenthesis/skipped/comment-annotation/workspaces/workspace0/main.py

@@ -0,0 +1,11 @@
+from checkpointing import checkpoint
+
+
+@checkpoint
+def foo(a):
+    print("Running")
+    return a
+
+
+if __name__ == "__main__":
+    print(foo(1))