Prepare docs for release 22.8.0 (#3248)

[etc/vim.git] / src / black / trans.py

diff --git a/src/black/trans.py b/src/black/trans.py
index 01aa80eaaf84760f765ae34eef651d7336e28c09..7ecfcef703d26e4ae9963254c4963c8561103d8e 100644 (file)
--- a/src/black/trans.py
+++ b/src/black/trans.py
@@ -1,10 +1,11 @@
 """
 String transformers that can split and merge strings.
 """
 """
 String transformers that can split and merge strings.
 """

+import re
+import sys

 from abc import ABC, abstractmethod
 from collections import defaultdict
 from dataclasses import dataclass
 from abc import ABC, abstractmethod
 from collections import defaultdict
 from dataclasses import dataclass

-import re

 from typing import (
     Any,
     Callable,
 from typing import (
     Any,
     Callable,


@@ -21,29 +22,38 @@ from typing import (
     TypeVar,
     Union,
 )
     TypeVar,
     Union,
 )

-import sys

 
 if sys.version_info < (3, 8):
 
 if sys.version_info < (3, 8):

-    from typing_extensions import Literal, Final
+    from typing_extensions import Final, Literal

 else:
     from typing import Literal, Final
 
 from mypy_extensions import trait
 
 else:
     from typing import Literal, Final
 
 from mypy_extensions import trait
 

-from black.rusty import Result, Ok, Err
-
-from black.mode import Feature
-from black.nodes import syms, replace_child, parent_type
-from black.nodes import is_empty_par, is_empty_lpar, is_empty_rpar
-from black.nodes import OPENING_BRACKETS, CLOSING_BRACKETS, STANDALONE_COMMENT
-from black.lines import Line, append_leaves

 from black.brackets import BracketMatchError
 from black.comments import contains_pragma_comment
 from black.brackets import BracketMatchError
 from black.comments import contains_pragma_comment

-from black.strings import has_triple_quotes, get_string_prefix, assert_is_leaf_string
-from black.strings import normalize_string_quotes
-
-from blib2to3.pytree import Leaf, Node
+from black.lines import Line, append_leaves
+from black.mode import Feature
+from black.nodes import (
+    CLOSING_BRACKETS,
+    OPENING_BRACKETS,
+    STANDALONE_COMMENT,
+    is_empty_lpar,
+    is_empty_par,
+    is_empty_rpar,
+    parent_type,
+    replace_child,
+    syms,
+)
+from black.rusty import Err, Ok, Result
+from black.strings import (
+    assert_is_leaf_string,
+    get_string_prefix,
+    has_triple_quotes,
+    normalize_string_quotes,
+)

 from blib2to3.pgen2 import token
 from blib2to3.pgen2 import token

+from blib2to3.pytree import Leaf, Node

 
 
 class CannotTransform(Exception):
 
 
 class CannotTransform(Exception):


@@ -121,7 +131,7 @@ def hug_power_op(line: Line, features: Collection[Feature]) -> Iterator[Line]:
 
         return False
 
 
         return False
 

-    leaves: List[Leaf] = []
+    new_line = line.clone()

     should_hug = False
     for idx, leaf in enumerate(line.leaves):
         new_leaf = leaf.clone()
     should_hug = False
     for idx, leaf in enumerate(line.leaves):
         new_leaf = leaf.clone()


@@ -139,18 +149,14 @@ def hug_power_op(line: Line, features: Collection[Feature]) -> Iterator[Line]:
         if should_hug:
             new_leaf.prefix = ""
 
         if should_hug:
             new_leaf.prefix = ""
 

-        leaves.append(new_leaf)
-
-    yield Line(
-        mode=line.mode,
-        depth=line.depth,
-        leaves=leaves,
-        comments=line.comments,
-        bracket_tracker=line.bracket_tracker,
-        inside_brackets=line.inside_brackets,
-        should_split_rhs=line.should_split_rhs,
-        magic_trailing_comma=line.magic_trailing_comma,
-    )
+        # We have to be careful to make a new line properly:
+        # - bracket related metadata must be maintained (handled by Line.append)
+        # - comments need to copied over, updating the leaf IDs they're attached to
+        new_line.append(new_leaf, preformatted=True)
+        for comment_leaf in line.comments_after(leaf):
+            new_line.append(comment_leaf, preformatted=True)
+
+    yield new_line

 
 
 class StringTransformer(ABC):
 
 
 class StringTransformer(ABC):


@@ -547,6 +553,9 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
 
             next_str_idx += 1
 
 
             next_str_idx += 1
 

+        # Take a note on the index of the non-STRING leaf.
+        non_string_idx = next_str_idx
+

         S_leaf = Leaf(token.STRING, S)
         if self.normalize_strings:
             S_leaf.value = normalize_string_quotes(S_leaf.value)
         S_leaf = Leaf(token.STRING, S)
         if self.normalize_strings:
             S_leaf.value = normalize_string_quotes(S_leaf.value)


@@ -566,7 +575,18 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
         string_leaf = Leaf(token.STRING, S_leaf.value.replace(BREAK_MARK, ""))
 
         if atom_node is not None:
         string_leaf = Leaf(token.STRING, S_leaf.value.replace(BREAK_MARK, ""))
 
         if atom_node is not None:

-            replace_child(atom_node, string_leaf)
+            # If not all children of the atom node are merged (this can happen
+            # when there is a standalone comment in the middle) ...
+            if non_string_idx - string_idx < len(atom_node.children):
+                # We need to replace the old STRING leaves with the new string leaf.
+                first_child_idx = LL[string_idx].remove()
+                for idx in range(string_idx + 1, non_string_idx):
+                    LL[idx].remove()
+                if first_child_idx is not None:
+                    atom_node.insert_child(first_child_idx, string_leaf)
+            else:
+                # Else replace the atom node with the new string leaf.
+                replace_child(atom_node, string_leaf)

 
         # Build the final line ('new_line') that this method will later return.
         new_line = line.clone()
 
         # Build the final line ('new_line') that this method will later return.
         new_line = line.clone()


@@ -1023,6 +1043,41 @@ class BaseStringSplitter(StringTransformer):
         max_string_length = self.line_length - offset
         return max_string_length
 
         max_string_length = self.line_length - offset
         return max_string_length
 

+    @staticmethod
+    def _prefer_paren_wrap_match(LL: List[Leaf]) -> Optional[int]:
+        """
+        Returns:
+            string_idx such that @LL[string_idx] is equal to our target (i.e.
+            matched) string, if this line matches the "prefer paren wrap" statement
+            requirements listed in the 'Requirements' section of the StringParenWrapper
+            class's docstring.
+                OR
+            None, otherwise.
+        """
+        # The line must start with a string.
+        if LL[0].type != token.STRING:
+            return None
+
+        matching_nodes = [
+            syms.listmaker,
+            syms.dictsetmaker,
+            syms.testlist_gexp,
+        ]
+        # If the string is an immediate child of a list/set/tuple literal...
+        if (
+            parent_type(LL[0]) in matching_nodes
+            or parent_type(LL[0].parent) in matching_nodes
+        ):
+            # And the string is surrounded by commas (or is the first/last child)...
+            prev_sibling = LL[0].prev_sibling
+            next_sibling = LL[0].next_sibling
+            if (not prev_sibling or prev_sibling.type == token.COMMA) and (
+                not next_sibling or next_sibling.type == token.COMMA
+            ):
+                return 0
+
+        return None
+

 
 def iter_fexpr_spans(s: str) -> Iterator[Tuple[int, int]]:
     """
 
 def iter_fexpr_spans(s: str) -> Iterator[Tuple[int, int]]:
     """


@@ -1118,6 +1173,9 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin):
     def do_splitter_match(self, line: Line) -> TMatchResult:
         LL = line.leaves
 
     def do_splitter_match(self, line: Line) -> TMatchResult:
         LL = line.leaves
 

+        if self._prefer_paren_wrap_match(LL) is not None:
+            return TErr("Line needs to be wrapped in parens first.")
+

         is_valid_index = is_valid_index_factory(LL)
 
         idx = 0
         is_valid_index = is_valid_index_factory(LL)
 
         idx = 0


@@ -1563,8 +1621,7 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin):
 
 class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
     """
 
 class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
     """

-    StringTransformer that splits non-"atom" strings (i.e. strings that do not
-    exist on lines by themselves).
+    StringTransformer that wraps strings in parens and then splits at the LPAR.

 
     Requirements:
         All of the requirements listed in BaseStringSplitter's docstring in
 
     Requirements:
         All of the requirements listed in BaseStringSplitter's docstring in


@@ -1584,6 +1641,11 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
             OR
         * The line is a dictionary key assignment where some valid key is being
         assigned the value of some string.
             OR
         * The line is a dictionary key assignment where some valid key is being
         assigned the value of some string.

+            OR
+        * The line starts with an "atom" string that prefers to be wrapped in
+        parens. It's preferred to be wrapped when it's is an immediate child of
+        a list/set/tuple literal, AND the string is surrounded by commas (or is
+        the first/last child).

 
     Transformations:
         The chosen string is wrapped in parentheses and then split at the LPAR.
 
     Transformations:
         The chosen string is wrapped in parentheses and then split at the LPAR.


@@ -1608,6 +1670,9 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
         changed such that it no longer needs to be given its own line,
         StringParenWrapper relies on StringParenStripper to clean up the
         parentheses it created.
         changed such that it no longer needs to be given its own line,
         StringParenWrapper relies on StringParenStripper to clean up the
         parentheses it created.

+
+        For "atom" strings that prefers to be wrapped in parens, it requires
+        StringSplitter to hold the split until the string is wrapped in parens.

     """
 
     def do_splitter_match(self, line: Line) -> TMatchResult:
     """
 
     def do_splitter_match(self, line: Line) -> TMatchResult:


@@ -1624,6 +1689,7 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
             or self._assert_match(LL)
             or self._assign_match(LL)
             or self._dict_match(LL)
             or self._assert_match(LL)
             or self._assign_match(LL)
             or self._dict_match(LL)

+            or self._prefer_paren_wrap_match(LL)

         )
 
         if string_idx is not None:
         )
 
         if string_idx is not None: