add sphinx docs skeleton (#71)

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 8a4eb05e5ad71cf04976c913a0f8bac6631bae7f..f03c4f16915309c817230916686ee0be90a8bb2d 100644 (file)
--- a/black.py
+++ b/black.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
 #!/usr/bin/env python3

+

 import asyncio
 from asyncio.base_events import BaseEventLoop
 from concurrent.futures import Executor, ProcessPoolExecutor
 import asyncio
 from asyncio.base_events import BaseEventLoop
 from concurrent.futures import Executor, ProcessPoolExecutor


@@ -21,7 +22,7 @@ from blib2to3 import pygram, pytree
 from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 
 from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 

-__version__ = "18.3a2"
+__version__ = "18.3a3"

 DEFAULT_LINE_LENGTH = 88
 # types
 syms = pygram.python_symbols
 DEFAULT_LINE_LENGTH = 88
 # types
 syms = pygram.python_symbols


@@ -43,7 +44,7 @@ class NothingChanged(UserWarning):
 class CannotSplit(Exception):
     """A readable split that fits the allotted line length is impossible.
 
 class CannotSplit(Exception):
     """A readable split that fits the allotted line length is impossible.
 

-    Raised by `left_hand_split()` and `right_hand_split()`.
+    Raised by `left_hand_split()`, `right_hand_split()`, and `delimiter_split()`.

     """
 
 
     """
 
 


@@ -61,7 +62,7 @@ class CannotSplit(Exception):
     is_flag=True,
     help=(
         "Don't write back the files, just return the status.  Return code 0 "
     is_flag=True,
     help=(
         "Don't write back the files, just return the status.  Return code 0 "

-        "means nothing changed.  Return code 1 means some files were "
+        "means nothing would change.  Return code 1 means some files would be "

         "reformatted.  Return code 123 means there was an internal error."
     ),
 )
         "reformatted.  Return code 123 means there was an internal error."
     ),
 )


@@ -99,10 +100,12 @@ def main(
         ctx.exit(0)
     elif len(sources) == 1:
         p = sources[0]
         ctx.exit(0)
     elif len(sources) == 1:
         p = sources[0]

-        report = Report()
+        report = Report(check=check)

         try:
             if not p.is_file() and str(p) == '-':
         try:
             if not p.is_file() and str(p) == '-':

-                changed = format_stdin_to_stdout(line_length=line_length, fast=fast)
+                changed = format_stdin_to_stdout(
+                    line_length=line_length, fast=fast, write_back=not check
+                )

             else:
                 changed = format_file_in_place(
                     p, line_length=line_length, fast=fast, write_back=not check
             else:
                 changed = format_file_in_place(
                     p, line_length=line_length, fast=fast, write_back=not check


@@ -178,7 +181,9 @@ def format_file_in_place(
     return True
 
 
     return True
 
 

-def format_stdin_to_stdout(line_length: int, fast: bool) -> bool:
+def format_stdin_to_stdout(
+    line_length: int, fast: bool, write_back: bool = False
+) -> bool:

     """Format file on stdin and pipe output to stdout. Return True if changed."""
     contents = sys.stdin.read()
     try:
     """Format file on stdin and pipe output to stdout. Return True if changed."""
     contents = sys.stdin.read()
     try:


@@ -189,7 +194,8 @@ def format_stdin_to_stdout(line_length: int, fast: bool) -> bool:
         return False
 
     finally:
         return False
 
     finally:

-        sys.stdout.write(contents)
+        if write_back:
+            sys.stdout.write(contents)

 
 
 def format_file_contents(
 
 
 def format_file_contents(


@@ -213,7 +219,6 @@ def format_str(src_contents: str, line_length: int) -> FileContent:
     """Reformats a string and returns new contents."""
     src_node = lib2to3_parse(src_contents)
     dst_contents = ""
     """Reformats a string and returns new contents."""
     src_node = lib2to3_parse(src_contents)
     dst_contents = ""

-    comments: List[Line] = []

     lines = LineGenerator()
     elt = EmptyLineTracker()
     py36 = is_python36(src_node)
     lines = LineGenerator()
     elt = EmptyLineTracker()
     py36 = is_python36(src_node)


@@ -225,41 +230,41 @@ def format_str(src_contents: str, line_length: int) -> FileContent:
         before, after = elt.maybe_empty_lines(current_line)
         for _ in range(before):
             dst_contents += str(empty_line)
         before, after = elt.maybe_empty_lines(current_line)
         for _ in range(before):
             dst_contents += str(empty_line)

-        if not current_line.is_comment:
-            for comment in comments:
-                dst_contents += str(comment)
-            comments = []
-            for line in split_line(current_line, line_length=line_length, py36=py36):
-                dst_contents += str(line)
-        else:
-            comments.append(current_line)
-    if comments:
-        if elt.previous_defs:
-            # Separate postscriptum comments from the last module-level def.
-            dst_contents += str(empty_line)
-            dst_contents += str(empty_line)
-        for comment in comments:
-            dst_contents += str(comment)
+        for line in split_line(current_line, line_length=line_length, py36=py36):
+            dst_contents += str(line)

     return dst_contents
 
 
     return dst_contents
 
 

+GRAMMARS = [
+    pygram.python_grammar_no_print_statement_no_exec_statement,
+    pygram.python_grammar_no_print_statement,
+    pygram.python_grammar_no_exec_statement,
+    pygram.python_grammar,
+]
+
+

 def lib2to3_parse(src_txt: str) -> Node:
     """Given a string with source, return the lib2to3 Node."""
     grammar = pygram.python_grammar_no_print_statement
 def lib2to3_parse(src_txt: str) -> Node:
     """Given a string with source, return the lib2to3 Node."""
     grammar = pygram.python_grammar_no_print_statement

-    drv = driver.Driver(grammar, pytree.convert)

     if src_txt[-1] != '\n':
         nl = '\r\n' if '\r\n' in src_txt[:1024] else '\n'
         src_txt += nl
     if src_txt[-1] != '\n':
         nl = '\r\n' if '\r\n' in src_txt[:1024] else '\n'
         src_txt += nl

-    try:
-        result = drv.parse_string(src_txt, True)
-    except ParseError as pe:
-        lineno, column = pe.context[1]
-        lines = src_txt.splitlines()
+    for grammar in GRAMMARS:
+        drv = driver.Driver(grammar, pytree.convert)

         try:
         try:

-            faulty_line = lines[lineno - 1]
-        except IndexError:
-            faulty_line = "<line number missing in source>"
-        raise ValueError(f"Cannot parse: {lineno}:{column}: {faulty_line}") from None
+            result = drv.parse_string(src_txt, True)
+            break
+
+        except ParseError as pe:
+            lineno, column = pe.context[1]
+            lines = src_txt.splitlines()
+            try:
+                faulty_line = lines[lineno - 1]
+            except IndexError:
+                faulty_line = "<line number missing in source>"
+            exc = ValueError(f"Cannot parse: {lineno}:{column}: {faulty_line}")
+    else:
+        raise exc from None

 
     if isinstance(result, Leaf):
         result = Node(syms.file_input, [result])
 
     if isinstance(result, Leaf):
         result = Node(syms.file_input, [result])


@@ -348,6 +353,7 @@ MATH_OPERATORS = {
     token.AMPER,
     token.PERCENT,
     token.CIRCUMFLEX,
     token.AMPER,
     token.PERCENT,
     token.CIRCUMFLEX,

+    token.TILDE,

     token.LEFTSHIFT,
     token.RIGHTSHIFT,
     token.DOUBLESTAR,
     token.LEFTSHIFT,
     token.RIGHTSHIFT,
     token.DOUBLESTAR,


@@ -413,7 +419,7 @@ class BracketTracker:
         """Returns True if there is an yet unmatched open bracket on the line."""
         return bool(self.bracket_match)
 
         """Returns True if there is an yet unmatched open bracket on the line."""
         return bool(self.bracket_match)
 

-    def max_priority(self, exclude: Iterable[LeafID] =()) -> int:
+    def max_priority(self, exclude: Iterable[LeafID] = ()) -> int:

         """Returns the highest priority of a delimiter found on the line.
 
         Values are consistent with what `is_delimiter()` returns.
         """Returns the highest priority of a delimiter found on the line.
 
         Values are consistent with what `is_delimiter()` returns.


@@ -517,10 +523,16 @@ class Line:
         ):
             return False
 
         ):
             return False
 

-        if closing.type == token.RSQB or closing.type == token.RBRACE:
+        if closing.type == token.RBRACE:

             self.leaves.pop()
             return True
 
             self.leaves.pop()
             return True
 

+        if closing.type == token.RSQB:
+            comma = self.leaves[-1]
+            if comma.parent and comma.parent.type == syms.listmaker:
+                self.leaves.pop()
+                return True
+

         # For parens let's check if it's safe to remove the comma.  If the
         # trailing one is the only one, we might mistakenly change a tuple
         # into a different type by removing the comma.
         # For parens let's check if it's safe to remove the comma.  If the
         # trailing one is the only one, we might mistakenly change a tuple
         # into a different type by removing the comma.


@@ -657,10 +669,6 @@ class EmptyLineTracker:
         (two on module-level), as well as providing an extra empty line after flow
         control keywords to make them more prominent.
         """
         (two on module-level), as well as providing an extra empty line after flow
         control keywords to make them more prominent.
         """

-        if current_line.is_comment:
-            # Don't count standalone comments towards previous empty lines.
-            return 0, 0
-

         before, after = self._maybe_empty_lines(current_line)
         before -= self.previous_after
         self.previous_after = after
         before, after = self._maybe_empty_lines(current_line)
         before -= self.previous_after
         self.previous_after = after


@@ -668,10 +676,14 @@ class EmptyLineTracker:
         return before, after
 
     def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
         return before, after
 
     def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:

+        max_allowed = 1
+        if current_line.is_comment and current_line.depth == 0:
+            max_allowed = 2

         if current_line.leaves:
             # Consume the first leaf's extra newlines.
             first_leaf = current_line.leaves[0]
         if current_line.leaves:
             # Consume the first leaf's extra newlines.
             first_leaf = current_line.leaves[0]

-            before = int('\n' in first_leaf.prefix)
+            before = first_leaf.prefix.count('\n')
+            before = min(before, max(before, max_allowed))

             first_leaf.prefix = ''
         else:
             before = 0
             first_leaf.prefix = ''
         else:
             before = 0


@@ -725,7 +737,6 @@ class LineGenerator(Visitor[Line]):
     in ways that will no longer stringify to valid Python code on the tree.
     """
     current_line: Line = Factory(Line)
     in ways that will no longer stringify to valid Python code on the tree.
     """
     current_line: Line = Factory(Line)

-    standalone_comments: List[Leaf] = Factory(list)

 
     def line(self, indent: int = 0) -> Iterator[Line]:
         """Generate a line.
 
     def line(self, indent: int = 0) -> Iterator[Line]:
         """Generate a line.


@@ -756,33 +767,22 @@ class LineGenerator(Visitor[Line]):
                     yield from self.line()
 
                 else:
                     yield from self.line()
 
                 else:

-                    # regular standalone comment, to be processed later (see
-                    # docstring in `generate_comments()`
-                    self.standalone_comments.append(comment)
-            normalize_prefix(node, inside_brackets=any_open_brackets)
-            if node.type not in WHITESPACE:
-                for comment in self.standalone_comments:
+                    # regular standalone comment

                     yield from self.line()
 
                     self.current_line.append(comment)
                     yield from self.line()
 
                     yield from self.line()
 
                     self.current_line.append(comment)
                     yield from self.line()
 

-                self.standalone_comments = []
+            normalize_prefix(node, inside_brackets=any_open_brackets)
+            if node.type not in WHITESPACE:

                 self.current_line.append(node)
         yield from super().visit_default(node)
 
                 self.current_line.append(node)
         yield from super().visit_default(node)
 

-    def visit_suite(self, node: Node) -> Iterator[Line]:
-        """Body of a statement after a colon."""
-        children = iter(node.children)
-        # Process newline before indenting.  It might contain an inline
-        # comment that should go right after the colon.
-        newline = next(children)
-        yield from self.visit(newline)
+    def visit_INDENT(self, node: Node) -> Iterator[Line]:

         yield from self.line(+1)
         yield from self.line(+1)

+        yield from self.visit_default(node)

 
 

-        for child in children:
-            yield from self.visit(child)
-
+    def visit_DEDENT(self, node: Node) -> Iterator[Line]:

         yield from self.line(-1)
 
     def visit_stmt(self, node: Node, keywords: Set[str]) -> Iterator[Line]:
         yield from self.line(-1)
 
     def visit_stmt(self, node: Node, keywords: Set[str]) -> Iterator[Line]:


@@ -872,7 +872,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"

-    if t == token.COLON and p.type != syms.subscript:
+    if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}:

         return NO
 
     prev = leaf.prev_sibling
         return NO
 
     prev = leaf.prev_sibling


@@ -885,30 +885,49 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
             return SPACE if prevp.type == token.COMMA else NO
 
         if prevp.type == token.EQUAL:
             return SPACE if prevp.type == token.COMMA else NO
 
         if prevp.type == token.EQUAL:

-            if prevp.parent and prevp.parent.type in {
-                syms.typedargslist,
-                syms.varargslist,
-                syms.parameters,
-                syms.arglist,
-                syms.argument,
-            }:
-                return NO
+            if prevp.parent:
+                if prevp.parent.type in {
+                    syms.arglist, syms.argument, syms.parameters, syms.varargslist
+                }:
+                    return NO
+
+                elif prevp.parent.type == syms.typedargslist:
+                    # A bit hacky: if the equal sign has whitespace, it means we
+                    # previously found it's a typed argument.  So, we're using
+                    # that, too.
+                    return prevp.prefix

 
         elif prevp.type == token.DOUBLESTAR:
             if prevp.parent and prevp.parent.type in {
 
         elif prevp.type == token.DOUBLESTAR:
             if prevp.parent and prevp.parent.type in {

-                syms.typedargslist,
-                syms.varargslist,
-                syms.parameters,

                 syms.arglist,
                 syms.arglist,

+                syms.argument,

                 syms.dictsetmaker,
                 syms.dictsetmaker,

+                syms.parameters,
+                syms.typedargslist,
+                syms.varargslist,

             }:
                 return NO
 
         elif prevp.type == token.COLON:
             }:
                 return NO
 
         elif prevp.type == token.COLON:

-            if prevp.parent and prevp.parent.type == syms.subscript:
+            if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:

                 return NO
 
                 return NO
 

-        elif prevp.parent and prevp.parent.type in {syms.factor, syms.star_expr}:
+        elif (
+            prevp.parent
+            and prevp.parent.type in {syms.factor, syms.star_expr}
+            and prevp.type in MATH_OPERATORS
+        ):
+            return NO
+
+        elif (
+            prevp.type == token.RIGHTSHIFT
+            and prevp.parent
+            and prevp.parent.type == syms.shift_expr
+            and prevp.prev_sibling
+            and prevp.prev_sibling.type == token.NAME
+            and prevp.prev_sibling.value == 'print'  # type: ignore
+        ):
+            # Python 2 print chevron

             return NO
 
     elif prev.type in OPENING_BRACKETS:
             return NO
 
     elif prev.type in OPENING_BRACKETS:


@@ -922,7 +941,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         if not prev or prev.type != token.COMMA:
             return NO
 
         if not prev or prev.type != token.COMMA:
             return NO
 

-    if p.type == syms.varargslist:
+    elif p.type == syms.varargslist:

         # lambdas
         if t == token.RPAR:
             return NO
         # lambdas
         if t == token.RPAR:
             return NO


@@ -1133,30 +1152,40 @@ def generate_comments(leaf: Leaf) -> Iterator[Leaf]:
     Inline comments are emitted as regular token.COMMENT leaves.  Standalone
     are emitted with a fake STANDALONE_COMMENT token identifier.
     """
     Inline comments are emitted as regular token.COMMENT leaves.  Standalone
     are emitted with a fake STANDALONE_COMMENT token identifier.
     """

-    if not leaf.prefix:
+    p = leaf.prefix
+    if not p:

         return
 
         return
 

-    if '#' not in leaf.prefix:
+    if '#' not in p:

         return
 
         return
 

-    before_comment, content = leaf.prefix.split('#', 1)
-    content = content.rstrip()
-    if content and (content[0] not in {' ', '!', '#'}):
-        content = ' ' + content
-    is_standalone_comment = (
-        '\n' in before_comment or '\n' in content or leaf.type == token.ENDMARKER
-    )
-    if not is_standalone_comment:
-        # simple trailing comment
-        yield Leaf(token.COMMENT, value='#' + content)
-        return
-
-    for line in ('#' + content).split('\n'):
+    nlines = 0
+    for index, line in enumerate(p.split('\n')):

         line = line.lstrip()
         line = line.lstrip()

+        if not line:
+            nlines += 1

         if not line.startswith('#'):
             continue
 
         if not line.startswith('#'):
             continue
 

-        yield Leaf(STANDALONE_COMMENT, line)
+        if index == 0 and leaf.type != token.ENDMARKER:
+            comment_type = token.COMMENT  # simple trailing comment
+        else:
+            comment_type = STANDALONE_COMMENT
+        yield Leaf(comment_type, make_comment(line), prefix='\n' * nlines)
+
+        nlines = 0
+
+
+def make_comment(content: str) -> str:
+    content = content.rstrip()
+    if not content:
+        return '#'
+
+    if content[0] == '#':
+        content = content[1:]
+    if content and content[0] not in ' !:#':
+        content = ' ' + content
+    return '#' + content

 
 
 def split_line(
 
 
 def split_line(


@@ -1379,9 +1408,11 @@ def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None:
     you'll lose your voting rights.
     """
     if not inside_brackets:
     you'll lose your voting rights.
     """
     if not inside_brackets:

-        spl = leaf.prefix.split('#', 1)
+        spl = leaf.prefix.split('#')

         if '\\' not in spl[0]:
         if '\\' not in spl[0]:

-            nl_count = spl[0].count('\n')
+            nl_count = spl[-1].count('\n')
+            if len(spl) > 1:
+                nl_count -= 1

             leaf.prefix = '\n' * nl_count
             return
 
             leaf.prefix = '\n' * nl_count
             return
 


@@ -1434,6 +1465,7 @@ def gen_python_files_in_dir(path: Path) -> Iterator[Path]:
 @dataclass
 class Report:
     """Provides a reformatting counter."""
 @dataclass
 class Report:
     """Provides a reformatting counter."""

+    check: bool = False

     change_count: int = 0
     same_count: int = 0
     failure_count: int = 0
     change_count: int = 0
     same_count: int = 0
     failure_count: int = 0


@@ -1441,7 +1473,8 @@ class Report:
     def done(self, src: Path, changed: bool) -> None:
         """Increment the counter for successful reformatting. Write out a message."""
         if changed:
     def done(self, src: Path, changed: bool) -> None:
         """Increment the counter for successful reformatting. Write out a message."""
         if changed:

-            out(f'reformatted {src}')
+            reformatted = 'would reformat' if self.check else 'reformatted'
+            out(f'{reformatted} {src}')

             self.change_count += 1
         else:
             out(f'{src} already well formatted, good job.', bold=False)
             self.change_count += 1
         else:
             out(f'{src} already well formatted, good job.', bold=False)


@@ -1460,7 +1493,7 @@ class Report:
         if self.failure_count:
             return 123
 
         if self.failure_count:
             return 123
 

-        elif self.change_count:
+        elif self.change_count and self.check:

             return 1
 
         return 0
             return 1
 
         return 0


@@ -1470,21 +1503,27 @@ class Report:
 
         Use `click.unstyle` to remove colors.
         """
 
         Use `click.unstyle` to remove colors.
         """

+        if self.check:
+            reformatted = "would be reformatted"
+            unchanged = "would be left unchanged"
+            failed = "would fail to reformat"
+        else:
+            reformatted = "reformatted"
+            unchanged = "left unchanged"
+            failed = "failed to reformat"

         report = []
         if self.change_count:
             s = 's' if self.change_count > 1 else ''
             report.append(
         report = []
         if self.change_count:
             s = 's' if self.change_count > 1 else ''
             report.append(

-                click.style(f'{self.change_count} file{s} reformatted', bold=True)
+                click.style(f'{self.change_count} file{s} {reformatted}', bold=True)

             )
         if self.same_count:
             s = 's' if self.same_count > 1 else ''
             )
         if self.same_count:
             s = 's' if self.same_count > 1 else ''

-            report.append(f'{self.same_count} file{s} left unchanged')
+            report.append(f'{self.same_count} file{s} {unchanged}')

         if self.failure_count:
             s = 's' if self.failure_count > 1 else ''
             report.append(
         if self.failure_count:
             s = 's' if self.failure_count > 1 else ''
             report.append(

-                click.style(
-                    f'{self.failure_count} file{s} failed to reformat', fg='red'
-                )
+                click.style(f'{self.failure_count} file{s} {failed}', fg='red')

             )
         return ', '.join(report) + '.'
 
             )
         return ', '.join(report) + '.'
 


@@ -1526,7 +1565,12 @@ def assert_equivalent(src: str, dst: str) -> None:
     try:
         src_ast = ast.parse(src)
     except Exception as exc:
     try:
         src_ast = ast.parse(src)
     except Exception as exc:

-        raise AssertionError(f"cannot parse source: {exc}") from None
+        major, minor = sys.version_info[:2]
+        raise AssertionError(
+            f"cannot use --safe with this file; failed to parse source file "
+            f"with Python {major}.{minor}'s builtin AST. Re-run with --fast "
+            f"or stop using deprecated Python 2 syntax. AST error message: {exc}"
+        )

 
     try:
         dst_ast = ast.parse(dst)
 
     try:
         dst_ast = ast.parse(dst)