Merge c571ffd into fe64e14

.travis.yml

@@ -2,6 +2,9 @@ language: python
 python:
  - "3.5"
  - "3.6"
+ - "3.7"
+ - "3.8"
+dist: xenial
 
 install:
  - pip install .

pragma/core/__init__.py

@@ -20,6 +20,8 @@ def _is_indexable(x):
 safe_new_contract('indexable', _is_indexable)
 safe_new_contract('literal', 'int|float|str|bool|tuple|list|None')
 for name, tp in inspect.getmembers(ast, inspect.isclass):
+    if name[0] == '_':  # python 3.8 added ast._AST which pycontracts does not like
+        continue
     safe_new_contract(name, tp)
 
 # Astor tries to get fancy by failing nicely, but in doing so they fail when traversing non-AST type node properties.

pragma/core/transformer.py

@@ -30,6 +30,17 @@ def function_ast(f):
     except (KeyError, AttributeError):  # pragma: nocover
         f_file = ''
 
+    try:
+        found = inspect.findsource(f)
+    except IndexError as err:
+        raise IOError((
+            'Discrepancy in number of decorator @magics expected by '
+            'inspect vs. __code__.co_firstlineno\n'
+            '{} in {}.\n'
+            'Try using the decorators after declaring the function'
+            'instead of @-magic').format(f, f_file)
+        ) from err
+
     root = ast.parse(textwrap.dedent(inspect.getsource(f)), f_file)
     return root, root.body[0].body, f_file
 
@@ -388,6 +399,10 @@ def inner(f):
                 func = glbls[f_mod.body[0].name]
                 if save_source:
                     func.__tempfile__ = temp
+                    # When there are other decorators, the co_firstlineno of *some* python distributions gets confused
+                    # and thinks they will be there even when they are not written to the file, causing readline overflow
+                    # So we put some empty lines to make them align
+                    temp.write('\n' * func.__code__.co_firstlineno)
                     temp.write(source)
                     temp.flush()
                 return func

pragma/lift.py

@@ -143,19 +143,17 @@ def __call__(self, f):
         new_kws = [ast.arg(arg=k, annotation=self._annotate(k, v)) for k, v in free_vars]
         new_kw_defaults = [self._get_default(k, v) for k, v in free_vars]
 
+        # python 3.8 introduced a new signature for ast.arguments.__init__, so use whatever they use
+        ast_arguments_dict = func_def.args.__dict__
+        ast_arguments_dict['kwonlyargs'] += new_kws
+        ast_arguments_dict['kw_defaults'] += new_kw_defaults
+
         new_func_def = ast.FunctionDef(
             name=func_def.name,
             body=f_body,
             decorator_list=[],  # func_def.decorator_list,
             returns=func_def.returns,
-            args=ast.arguments(
-                args=func_def.args.args,
-                vararg=func_def.args.vararg,
-                kwarg=func_def.args.kwarg,
-                defaults=func_def.args.defaults,
-                kwonlyargs=func_def.args.kwonlyargs + new_kws,
-                kw_defaults=func_def.args.kw_defaults + new_kw_defaults
-            )
+            args=ast.arguments(**ast_arguments_dict)
         )
 
         f_mod.body[0] = new_func_def

tests/test_collapse_literals.py

@@ -40,6 +40,27 @@ def f():
         ''')
         self.assertEqual(f.strip(), result.strip())
 
+    def test_repeated_decoration(self):
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        @pragma.collapse_literals
+        def f():
+            return 2
+        f = pragma.collapse_literals(f)
+
+        result = '''
+        def f():
+            return 2
+        '''
+
+        self.assertSourceEqual(f, result)
+        self.assertEqual(f(), 2)
+
     def test_vars(self):
         @pragma.collapse_literals(return_source=True)
         def f():
@@ -288,17 +309,41 @@ def test_simple_functions(self):
         def f():
             print(len(a))
             print(sum(a))
+            print(-a[0])
+            print(a[0] + a[1])
             print(a)
 
         result = '''
         def f():
             print(4)
             print(10)
+            print(-1)
+            print(3)
             print(a)
         '''
 
         self.assertSourceEqual(f, result)
 
+    def test_indexable_operations(self):
+        dct = dict(a=1, b=2, c=3, d=4)
+
+        @pragma.collapse_literals
+        def f():
+            print(len(dct))
+            print(-dct['a'])
+            print(dct['a'] + dct['b'])
+            print(dct)
+
+        result = '''
+        def f():
+            print(4)
+            print(-1)
+            print(3)
+            print(dct)
+        '''
+
+        self.assertSourceEqual(f, result)
+
     def test_reduction(self):
         a = [1, 2, 3]