python.el: Enhance docstring detection following PEP-257.

* lisp/progmodes/python.el (python-docstring-at-p): Remove function.
(python-info-assignment-statement-p): New function.
(python-info-assignment-continuation-line-p): Use it.
(python-info-docstring-p): New function.
(python-font-lock-syntactic-face-function)
(python-fill-string): Use it.

* test/automated/python-tests.el (python-info-assignment-statement-p-1)
(python-info-assignment-statement-p-2)
(python-info-assignment-statement-p-3, python-info-docstring-p-1)
(python-info-docstring-p-2, python-info-docstring-p-3)
(python-info-docstring-p-4, python-info-docstring-p-5)
(python-info-docstring-p-6): New tests.

2 files changed, 182 insertions, 0 deletions

diff --git a/test/ChangeLog b/test/ChangeLog
index f7bec2ee119..813f5dd42b7 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,12 @@
+2015-04-06  Fabián Ezequiel Gallina  <fgallina@gnu.org>
+
+        * automated/python-tests.el (python-info-assignment-statement-p-1)
+        (python-info-assignment-statement-p-2)
+        (python-info-assignment-statement-p-3, python-info-docstring-p-1)
+        (python-info-docstring-p-2, python-info-docstring-p-3)
+        (python-info-docstring-p-4, python-info-docstring-p-5)
+        (python-info-docstring-p-6): New tests.
+
 2015-04-01  Artur Malabarba  <bruce.connor.am@gmail.com>
 
         * automated/package-test.el: Avoid async while testing.
diff --git a/test/automated/python-tests.el b/test/automated/python-tests.el
index b377a26f77a..22c111fc04a 100644
--- a/test/automated/python-tests.el
+++ b/test/automated/python-tests.el
@@ -4273,6 +4273,49 @@ def foo(a,
    (python-tests-look-at "c):")
    (should (not (python-info-block-continuation-line-p)))))
 
+(ert-deftest python-info-assignment-statement-p-1 ()
+  (python-tests-with-temp-buffer
+   "
+data = foo(), bar() \\\\
+       baz(), 4 \\\\
+       5, 6
+"
+   (python-tests-look-at "data = foo(), bar()")
+   (should (python-info-assignment-statement-p))
+   (should (python-info-assignment-statement-p t))
+   (python-tests-look-at "baz(), 4")
+   (should (python-info-assignment-statement-p))
+   (should (not (python-info-assignment-statement-p t)))
+   (python-tests-look-at "5, 6")
+   (should (python-info-assignment-statement-p))
+   (should (not (python-info-assignment-statement-p t)))))
+
+(ert-deftest python-info-assignment-statement-p-2 ()
+  (python-tests-with-temp-buffer
+   "
+data = (foo(), bar()
+        baz(), 4
+        5, 6)
+"
+   (python-tests-look-at "data = (foo(), bar()")
+   (should (python-info-assignment-statement-p))
+   (should (python-info-assignment-statement-p t))
+   (python-tests-look-at "baz(), 4")
+   (should (python-info-assignment-statement-p))
+   (should (not (python-info-assignment-statement-p t)))
+   (python-tests-look-at "5, 6)")
+   (should (python-info-assignment-statement-p))
+   (should (not (python-info-assignment-statement-p t)))))
+
+(ert-deftest python-info-assignment-statement-p-3 ()
+  (python-tests-with-temp-buffer
+   "
+data '=' 42
+"
+   (python-tests-look-at "data '=' 42")
+   (should (not (python-info-assignment-statement-p)))
+   (should (not (python-info-assignment-statement-p t)))))
+
 (ert-deftest python-info-assignment-continuation-line-p-1 ()
   (python-tests-with-temp-buffer
    "
@@ -4360,6 +4403,136 @@ foo = True  # another comment
    (forward-line 1)
    (should (python-info-current-line-empty-p))))
 
+(ert-deftest python-info-docstring-p-1 ()
+  "Test module docstring detection."
+  (python-tests-with-temp-buffer
+   "# -*- coding: utf-8 -*-
+#!/usr/bin/python
+
+'''
+Module Docstring Django style.
+'''
+u'''Additional module docstring.'''
+'''Not a module docstring.'''
+"
+   (python-tests-look-at "Module Docstring Django style.")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "u'''Additional module docstring.'''")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Not a module docstring.'''")
+   (should (not (python-info-docstring-p)))))
+
+(ert-deftest python-info-docstring-p-2 ()
+  "Test variable docstring detection."
+  (python-tests-with-temp-buffer
+   "
+variable = 42
+U'''Variable docstring.'''
+'''Additional variable docstring.'''
+'''Not a variable docstring.'''
+"
+   (python-tests-look-at "Variable docstring.")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "u'''Additional variable docstring.'''")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Not a variable docstring.'''")
+   (should (not (python-info-docstring-p)))))
+
+(ert-deftest python-info-docstring-p-3 ()
+  "Test function docstring detection."
+  (python-tests-with-temp-buffer
+   "
+def func(a, b):
+    r'''
+    Function docstring.
+
+    onetwo style.
+    '''
+    R'''Additional function docstring.'''
+    '''Not a function docstring.'''
+    return a + b
+"
+   (python-tests-look-at "Function docstring.")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "R'''Additional function docstring.'''")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Not a function docstring.'''")
+   (should (not (python-info-docstring-p)))))
+
+(ert-deftest python-info-docstring-p-4 ()
+  "Test class docstring detection."
+  (python-tests-with-temp-buffer
+   "
+class Class:
+    ur'''
+    Class docstring.
+
+    symmetric style.
+    '''
+    uR'''
+    Additional class docstring.
+    '''
+    '''Not a class docstring.'''
+    pass
+"
+   (python-tests-look-at "Class docstring.")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "uR'''")  ;; Additional class docstring
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Not a class docstring.'''")
+   (should (not (python-info-docstring-p)))))
+
+(ert-deftest python-info-docstring-p-5 ()
+  "Test class attribute docstring detection."
+  (python-tests-with-temp-buffer
+   "
+class Class:
+    attribute = 42
+    Ur'''
+    Class attribute docstring.
+
+    pep-257 style.
+
+    '''
+    UR'''
+    Additional class attribute docstring.
+    '''
+    '''Not a class attribute docstring.'''
+    pass
+"
+   (python-tests-look-at "Class attribute docstring.")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "UR'''")  ;; Additional class attr docstring
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Not a class attribute docstring.'''")
+   (should (not (python-info-docstring-p)))))
+
+(ert-deftest python-info-docstring-p-6 ()
+  "Test class method docstring detection."
+  (python-tests-with-temp-buffer
+   "
+class Class:
+
+    def __init__(self, a, b):
+        self.a = a
+        self.b = b
+
+    def __call__(self):
+        '''Method docstring.
+
+        pep-257-nn style.
+        '''
+        '''Additional method docstring.'''
+        '''Not a method docstring.'''
+        return self.a + self.b
+"
+   (python-tests-look-at "Method docstring.")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Additional method docstring.'''")
+   (should (python-info-docstring-p))
+   (python-tests-look-at "'''Not a method docstring.'''")
+   (should (not (python-info-docstring-p)))))
+
 (ert-deftest python-info-encoding-from-cookie-1 ()
   "Should detect it on first line."
   (python-tests-with-temp-buffer