Misc updates and types annotations + unused parameter deprecation

lib/python/pyflyby/_file.py

@@ -4,13 +4,13 @@
 
 
 
-from   functools                import total_ordering
+from   functools                import total_ordering, cached_property
 import io
 import os
 import re
 import sys
 
-from   pyflyby._util            import cached_attribute, cmp, memoize
+from   pyflyby._util            import cmp, memoize
 
 
 class UnsafeFilenameError(ValueError):
@@ -28,6 +28,8 @@ class Filename(object):
       Filename('/etc/passwd')
 
     """
+    _filename: str
+
     def __new__(cls, arg):
         if isinstance(arg, cls):
             return arg
@@ -85,7 +87,7 @@ def __cmp__(self, o):
             return NotImplemented
         return cmp(self._filename, o._filename)
 
-    @cached_attribute
+    @cached_property
     def ext(self):
         """
         Returns the extension of this filename, including the dot.
@@ -99,15 +101,15 @@ def ext(self):
             return None
         return dot + rhs
 
-    @cached_attribute
+    @cached_property
     def base(self):
         return os.path.basename(self._filename)
 
-    @cached_attribute
+    @cached_property
     def dir(self):
         return type(self)(os.path.dirname(self._filename))
 
-    @cached_attribute
+    @cached_property
     def real(self):
         return type(self)(os.path.realpath(self._filename))
 
@@ -338,6 +340,8 @@ class FileText:
     Represents a contiguous sequence of lines from a file.
     """
 
+    filename: Filename
+
     def __new__(cls, arg, filename=None, startpos=None):
         """
         Return a new ``FileText`` instance.
@@ -394,7 +398,7 @@ def _from_lines(cls, lines, filename, startpos):
         self.startpos = startpos
         return self
 
-    @cached_attribute
+    @cached_property
     def lines(self):
         r"""
         Lines that have been split by newline.
@@ -414,7 +418,7 @@ def lines(self):
         # (or requires extra work to process if we use splitlines(True)).
         return tuple(self.joined.split('\n'))
 
-    @cached_attribute
+    @cached_property
     def joined(self): # used if only initialized with 'lines'
         return '\n'.join(self.lines)
 
@@ -441,7 +445,7 @@ def alter(self, filename=None, startpos=None):
             result.startpos = startpos
             return result
 
-    @cached_attribute
+    @cached_property
     def endpos(self):
         """
         The position after the last character in the text.

lib/python/pyflyby/_imports2s.py

@@ -200,12 +200,10 @@ def insert_new_blocks_after_comments(self, blocks):
                     # insert in the middle.
                     self.blocks[:1] = (
                         [SourceToSourceTransformation(
-                            PythonBlock.concatenate(statements[:idx],
-                                                    assume_contiguous=True))] +
+                            PythonBlock.concatenate(statements[:idx]))] +
                         blocks +
                         [SourceToSourceTransformation(
-                            PythonBlock.concatenate(statements[idx:],
-                                                    assume_contiguous=True))])
+                            PythonBlock.concatenate(statements[idx:]))])
                 break
         else:
             # First block is entirely comments, so just insert after it.

lib/python/pyflyby/_parse.py

@@ -1,7 +1,7 @@
 # pyflyby/_parse.py.
 # Copyright (C) 2011, 2012, 2013, 2014, 2015, 2018 Karl Chen.
 # License: MIT http://opensource.org/licenses/MIT
-
+from __future__ import annotations
 
 
 import ast
@@ -13,6 +13,8 @@
 import sys
 from   textwrap                 import dedent
 import types
+from   typing                   import Optional
+import warnings
 
 from   pyflyby._file            import FilePos, FileText, Filename
 from   pyflyby._flags           import CompilerFlags
@@ -22,6 +24,8 @@
 
 from ast import TypeIgnore, AsyncFunctionDef
 
+_sentinel = object()
+
 
 def _is_comment_or_blank(line):
     """
@@ -741,7 +745,7 @@ class _DummyAst_Node(object):
     pass
 
 
-class PythonStatement(object):
+class PythonStatement:
     r"""
     Representation of a top-level Python statement or consecutive
     comments/blank lines.
@@ -753,7 +757,9 @@ class PythonStatement(object):
     top-level AST node.
     """
 
-    def __new__(cls, arg, filename=None, startpos=None, flags=None):
+    block: PythonBlock
+
+    def __new__(cls, arg:PythonStatement, filename=None, startpos=None, flags=None):
         if isinstance(arg, cls):
             if filename is startpos is flags is None:
                 return arg
@@ -773,23 +779,24 @@ def __new__(cls, arg, filename=None, startpos=None, flags=None):
         raise TypeError("PythonStatement: unexpected %s" % (type(arg).__name__,))
 
     @classmethod
-    def _construct_from_block(cls, block):
+    def _construct_from_block(cls, block:PythonBlock):
+        assert isinstance(block, PythonBlock), repr(block)
         # Only to be used by PythonBlock.
         assert isinstance(block, PythonBlock)
         self = object.__new__(cls)
         self.block = block
         return self
 
     @property
-    def text(self):
+    def text(self) -> FileText:
         """
         :rtype:
           `FileText`
         """
         return self.block.text
 
     @property
-    def filename(self):
+    def filename(self) -> Optional[str]:
         """
         :rtype:
           `Filename`
@@ -828,9 +835,17 @@ def ast_node(self):
             return ast_nodes[0]
         raise AssertionError("More than one AST node in block")
 
+    @property
+    def is_blank(self):
+        return self.ast_node is None and self.text.joined.strip() == ''
+
+    @property
+    def is_comment(self):
+        return self.ast_node is None and self.text.joined.strip() != ''
+
     @property
     def is_comment_or_blank(self):
-        return self.ast_node is None
+        return self.is_comment or self.is_blank
 
     @property
     def is_comment_or_blank_or_string_literal(self):
@@ -898,7 +913,7 @@ def __hash__(self):
 
 
 @total_ordering
-class PythonBlock(object):
+class PythonBlock:
     r"""
     Representation of a sequence of consecutive top-level
     `PythonStatement` (s).
@@ -993,17 +1008,21 @@ def __construct_from_annotated_ast(cls, annotated_ast_nodes, text, flags):
         return self
 
     @classmethod
-    def concatenate(cls, blocks, assume_contiguous=False):
+    def concatenate(cls, blocks, assume_contiguous=_sentinel):
         """
         Concatenate a bunch of blocks into one block.
 
         :type blocks:
           sequence of `PythonBlock` s and/or `PythonStatement` s
         :param assume_contiguous:
+          Deprecated, always True
           Whether to assume, without checking, that the input blocks were
           originally all contiguous.  This must be set to True to indicate the
           caller understands the assumption; False is not implemented.
         """
+        if assume_contiguous is not _sentinel:
+            warnings.warn('`assume_continuous` is deprecated and considered always `True`')
+            assume_contiguous = True
         if not assume_contiguous:
             raise NotImplementedError
         blocks = [PythonBlock(b) for b in blocks]
@@ -1248,7 +1267,7 @@ def groupby(self, predicate):
         cls = type(self)
         for pred, stmts in groupby(self.statements, predicate):
             blocks = [s.block for s in stmts]
-            yield pred, cls.concatenate(blocks, assume_contiguous=True)
+            yield pred, cls.concatenate(blocks)
 
     def string_literals(self):
         r"""