]> git.madduck.net Git - etc/vim.git/blobdiff - src/black/trans.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Update documentation regarding isort compatibility (#3567)
[etc/vim.git] / src / black / trans.py
index b08a6d243d8981c90b8c9a38f396163c4a00f5b8..a6a416e71bc4c4e484e1a74c0949341e5908d67a 100644 (file)
@@ -30,10 +30,9 @@ else:
 
 from mypy_extensions import trait
 
-from black.brackets import BracketMatchError
 from black.comments import contains_pragma_comment
 from black.lines import Line, append_leaves
-from black.mode import Feature
+from black.mode import Feature, Mode
 from black.nodes import (
     CLOSING_BRACKETS,
     OPENING_BRACKETS,
@@ -41,6 +40,7 @@ from black.nodes import (
     is_empty_lpar,
     is_empty_par,
     is_empty_rpar,
+    is_part_of_annotation,
     parent_type,
     replace_child,
     syms,
@@ -63,13 +63,13 @@ class CannotTransform(Exception):
 # types
 T = TypeVar("T")
 LN = Union[Leaf, Node]
-Transformer = Callable[[Line, Collection[Feature]], Iterator[Line]]
+Transformer = Callable[[Line, Collection[Feature], Mode], Iterator[Line]]
 Index = int
 NodeType = int
 ParserState = int
 StringID = int
 TResult = Result[T, CannotTransform]  # (T)ransform Result
-TMatchResult = TResult[Index]
+TMatchResult = TResult[List[Index]]
 
 
 def TErr(err_msg: str) -> Err[CannotTransform]:
@@ -81,7 +81,9 @@ def TErr(err_msg: str) -> Err[CannotTransform]:
     return Err(cant_transform)
 
 
-def hug_power_op(line: Line, features: Collection[Feature]) -> Iterator[Line]:
+def hug_power_op(
+    line: Line, features: Collection[Feature], mode: Mode
+) -> Iterator[Line]:
     """A transformer which normalizes spacing around power operators."""
 
     # Performance optimization to avoid unnecessary Leaf clones and other ops.
@@ -198,14 +200,19 @@ class StringTransformer(ABC):
     def do_match(self, line: Line) -> TMatchResult:
         """
         Returns:
-            * Ok(string_idx) such that `line.leaves[string_idx]` is our target
-            string, if a match was able to be made.
+            * Ok(string_indices) such that for each index, `line.leaves[index]`
+            is our target string if a match was able to be made. For
+            transformers that don't result in more lines (e.g. StringMerger,
+            StringParenStripper), multiple matches and transforms are done at
+            once to reduce the complexity.
                 OR
-            * Err(CannotTransform), if a match was not able to be made.
+            * Err(CannotTransform), if no match could be made.
         """
 
     @abstractmethod
-    def do_transform(self, line: Line, string_idx: int) -> Iterator[TResult[Line]]:
+    def do_transform(
+        self, line: Line, string_indices: List[int]
+    ) -> Iterator[TResult[Line]]:
         """
         Yields:
             * Ok(new_line) where new_line is the new transformed line.
@@ -223,7 +230,9 @@ class StringTransformer(ABC):
             yield an CannotTransform after that point.)
         """
 
-    def __call__(self, line: Line, _features: Collection[Feature]) -> Iterator[Line]:
+    def __call__(
+        self, line: Line, _features: Collection[Feature], _mode: Mode
+    ) -> Iterator[Line]:
         """
         StringTransformer instances have a call signature that mirrors that of
         the Transformer type.
@@ -246,9 +255,9 @@ class StringTransformer(ABC):
                 " this line as one that it can transform."
             ) from cant_transform
 
-        string_idx = match_result.ok()
+        string_indices = match_result.ok()
 
-        for line_result in self.do_transform(line, string_idx):
+        for line_result in self.do_transform(line, string_indices):
             if isinstance(line_result, Err):
                 cant_transform = line_result.err()
                 raise CannotTransform(
@@ -351,7 +360,7 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
 
     Requirements:
         (A) The line contains adjacent strings such that ALL of the validation checks
-        listed in StringMerger.__validate_msg(...)'s docstring pass.
+        listed in StringMerger._validate_msg(...)'s docstring pass.
             OR
         (B) The line contains a string which uses line continuation backslashes.
 
@@ -371,28 +380,50 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
 
         is_valid_index = is_valid_index_factory(LL)
 
-        for i, leaf in enumerate(LL):
+        string_indices = []
+        idx = 0
+        while is_valid_index(idx):
+            leaf = LL[idx]
             if (
                 leaf.type == token.STRING
-                and is_valid_index(i + 1)
-                and LL[i + 1].type == token.STRING
+                and is_valid_index(idx + 1)
+                and LL[idx + 1].type == token.STRING
             ):
-                return Ok(i)
+                if not is_part_of_annotation(leaf):
+                    string_indices.append(idx)
+
+                # Advance to the next non-STRING leaf.
+                idx += 2
+                while is_valid_index(idx) and LL[idx].type == token.STRING:
+                    idx += 1
 
-            if leaf.type == token.STRING and "\\\n" in leaf.value:
-                return Ok(i)
+            elif leaf.type == token.STRING and "\\\n" in leaf.value:
+                string_indices.append(idx)
+                # Advance to the next non-STRING leaf.
+                idx += 1
+                while is_valid_index(idx) and LL[idx].type == token.STRING:
+                    idx += 1
+
+            else:
+                idx += 1
 
-        return TErr("This line has no strings that need merging.")
+        if string_indices:
+            return Ok(string_indices)
+        else:
+            return TErr("This line has no strings that need merging.")
 
-    def do_transform(self, line: Line, string_idx: int) -> Iterator[TResult[Line]]:
+    def do_transform(
+        self, line: Line, string_indices: List[int]
+    ) -> Iterator[TResult[Line]]:
         new_line = line
+
         rblc_result = self._remove_backslash_line_continuation_chars(
-            new_line, string_idx
+            new_line, string_indices
         )
         if isinstance(rblc_result, Ok):
             new_line = rblc_result.ok()
 
-        msg_result = self._merge_string_group(new_line, string_idx)
+        msg_result = self._merge_string_group(new_line, string_indices)
         if isinstance(msg_result, Ok):
             new_line = msg_result.ok()
 
@@ -413,7 +444,7 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
 
     @staticmethod
     def _remove_backslash_line_continuation_chars(
-        line: Line, string_idx: int
+        line: Line, string_indices: List[int]
     ) -> TResult[Line]:
         """
         Merge strings that were split across multiple lines using
@@ -427,34 +458,44 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
         """
         LL = line.leaves
 
-        string_leaf = LL[string_idx]
-        if not (
-            string_leaf.type == token.STRING
-            and "\\\n" in string_leaf.value
-            and not has_triple_quotes(string_leaf.value)
-        ):
+        indices_to_transform = []
+        for string_idx in string_indices:
+            string_leaf = LL[string_idx]
+            if (
+                string_leaf.type == token.STRING
+                and "\\\n" in string_leaf.value
+                and not has_triple_quotes(string_leaf.value)
+            ):
+                indices_to_transform.append(string_idx)
+
+        if not indices_to_transform:
             return TErr(
-                f"String leaf {string_leaf} does not contain any backslash line"
-                " continuation characters."
+                "Found no string leaves that contain backslash line continuation"
+                " characters."
             )
 
         new_line = line.clone()
         new_line.comments = line.comments.copy()
         append_leaves(new_line, line, LL)
 
-        new_string_leaf = new_line.leaves[string_idx]
-        new_string_leaf.value = new_string_leaf.value.replace("\\\n", "")
+        for string_idx in indices_to_transform:
+            new_string_leaf = new_line.leaves[string_idx]
+            new_string_leaf.value = new_string_leaf.value.replace("\\\n", "")
 
         return Ok(new_line)
 
-    def _merge_string_group(self, line: Line, string_idx: int) -> TResult[Line]:
+    def _merge_string_group(
+        self, line: Line, string_indices: List[int]
+    ) -> TResult[Line]:
         """
-        Merges string group (i.e. set of adjacent strings) where the first
-        string in the group is `line.leaves[string_idx]`.
+        Merges string groups (i.e. set of adjacent strings).
+
+        Each index from `string_indices` designates one string group's first
+        leaf in `line.leaves`.
 
         Returns:
             Ok(new_line), if ALL of the validation checks found in
-            __validate_msg(...) pass.
+            _validate_msg(...) pass.
                 OR
             Err(CannotTransform), otherwise.
         """
@@ -462,10 +503,54 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
 
         is_valid_index = is_valid_index_factory(LL)
 
-        vresult = self._validate_msg(line, string_idx)
-        if isinstance(vresult, Err):
-            return vresult
+        # A dict of {string_idx: tuple[num_of_strings, string_leaf]}.
+        merged_string_idx_dict: Dict[int, Tuple[int, Leaf]] = {}
+        for string_idx in string_indices:
+            vresult = self._validate_msg(line, string_idx)
+            if isinstance(vresult, Err):
+                continue
+            merged_string_idx_dict[string_idx] = self._merge_one_string_group(
+                LL, string_idx, is_valid_index
+            )
 
+        if not merged_string_idx_dict:
+            return TErr("No string group is merged")
+
+        # Build the final line ('new_line') that this method will later return.
+        new_line = line.clone()
+        previous_merged_string_idx = -1
+        previous_merged_num_of_strings = -1
+        for i, leaf in enumerate(LL):
+            if i in merged_string_idx_dict:
+                previous_merged_string_idx = i
+                previous_merged_num_of_strings, string_leaf = merged_string_idx_dict[i]
+                new_line.append(string_leaf)
+
+            if (
+                previous_merged_string_idx
+                <= i
+                < previous_merged_string_idx + previous_merged_num_of_strings
+            ):
+                for comment_leaf in line.comments_after(LL[i]):
+                    new_line.append(comment_leaf, preformatted=True)
+                continue
+
+            append_leaves(new_line, line, [leaf])
+
+        return Ok(new_line)
+
+    def _merge_one_string_group(
+        self, LL: List[Leaf], string_idx: int, is_valid_index: Callable[[int], bool]
+    ) -> Tuple[int, Leaf]:
+        """
+        Merges one string group where the first string in the group is
+        `LL[string_idx]`.
+
+        Returns:
+            A tuple of `(num_of_strings, leaf)` where `num_of_strings` is the
+            number of strings merged and `leaf` is the newly merged string
+            to be replaced in the new line.
+        """
         # If the string group is wrapped inside an Atom node, we must make sure
         # to later replace that Atom with our new (merged) string leaf.
         atom_node = LL[string_idx].parent
@@ -491,6 +576,12 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
                 characters have been escaped.
             """
             assert_is_leaf_string(string)
+            if "f" in string_prefix:
+                string = _toggle_fexpr_quotes(string, QUOTE)
+                # After quotes toggling, quotes in expressions won't be escaped
+                # because quotes can't be reused in f-strings. So we can simply
+                # let the escaping logic below run without knowing f-string
+                # expressions.
 
             RE_EVEN_BACKSLASHES = r"(?:(?<!\\)(?:\\\\)*)"
             naked_string = string[len(string_prefix) + 1 : -1]
@@ -588,27 +679,14 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
                 # 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()
-        for i, leaf in enumerate(LL):
-            if i == string_idx:
-                new_line.append(string_leaf)
-
-            if string_idx <= i < string_idx + num_of_strings:
-                for comment_leaf in line.comments_after(LL[i]):
-                    new_line.append(comment_leaf, preformatted=True)
-                continue
-
-            append_leaves(new_line, line, [leaf])
-
         self.add_custom_splits(string_leaf.value, custom_splits)
-        return Ok(new_line)
+        return num_of_strings, string_leaf
 
     @staticmethod
     def _validate_msg(line: Line, string_idx: int) -> TResult[None]:
         """Validate (M)erge (S)tring (G)roup
 
-        Transform-time string validation logic for __merge_string_group(...).
+        Transform-time string validation logic for _merge_string_group(...).
 
         Returns:
             * Ok(None), if ALL validation checks (listed below) pass.
@@ -622,6 +700,11 @@ class StringMerger(StringTransformer, CustomSplitMapMixin):
                 - The set of all string prefixes in the string group is of
                   length greater than one and is not equal to {"", "f"}.
                 - The string group consists of raw strings.
+                - The string group is stringified type annotations. We don't want to
+                  process stringified type annotations since pyright doesn't support
+                  them spanning multiple string values. (NOTE: mypy, pytype, pyre do
+                  support them, so we can change if pyright also gains support in the
+                  future. See https://github.com/microsoft/pyright/issues/4359.)
         """
         # We first check for "inner" stand-alone comments (i.e. stand-alone
         # comments that have a string leaf before them AND after them).
@@ -711,7 +794,15 @@ class StringParenStripper(StringTransformer):
 
         is_valid_index = is_valid_index_factory(LL)
 
-        for idx, leaf in enumerate(LL):
+        string_indices = []
+
+        idx = -1
+        while True:
+            idx += 1
+            if idx >= len(LL):
+                break
+            leaf = LL[idx]
+
             # Should be a string...
             if leaf.type != token.STRING:
                 continue
@@ -793,45 +884,73 @@ class StringParenStripper(StringTransformer):
                 }:
                     continue
 
-                return Ok(string_idx)
+                string_indices.append(string_idx)
+                idx = string_idx
+                while idx < len(LL) - 1 and LL[idx + 1].type == token.STRING:
+                    idx += 1
 
+        if string_indices:
+            return Ok(string_indices)
         return TErr("This line has no strings wrapped in parens.")
 
-    def do_transform(self, line: Line, string_idx: int) -> Iterator[TResult[Line]]:
+    def do_transform(
+        self, line: Line, string_indices: List[int]
+    ) -> Iterator[TResult[Line]]:
         LL = line.leaves
 
-        string_parser = StringParser()
-        rpar_idx = string_parser.parse(LL, string_idx)
+        string_and_rpar_indices: List[int] = []
+        for string_idx in string_indices:
+            string_parser = StringParser()
+            rpar_idx = string_parser.parse(LL, string_idx)
+
+            should_transform = True
+            for leaf in (LL[string_idx - 1], LL[rpar_idx]):
+                if line.comments_after(leaf):
+                    # Should not strip parentheses which have comments attached
+                    # to them.
+                    should_transform = False
+                    break
+            if should_transform:
+                string_and_rpar_indices.extend((string_idx, rpar_idx))
 
-        for leaf in (LL[string_idx - 1], LL[rpar_idx]):
-            if line.comments_after(leaf):
-                yield TErr(
-                    "Will not strip parentheses which have comments attached to them."
-                )
-                return
+        if string_and_rpar_indices:
+            yield Ok(self._transform_to_new_line(line, string_and_rpar_indices))
+        else:
+            yield Err(
+                CannotTransform("All string groups have comments attached to them.")
+            )
+
+    def _transform_to_new_line(
+        self, line: Line, string_and_rpar_indices: List[int]
+    ) -> Line:
+        LL = line.leaves
 
         new_line = line.clone()
         new_line.comments = line.comments.copy()
-        try:
-            append_leaves(new_line, line, LL[: string_idx - 1])
-        except BracketMatchError:
-            # HACK: I believe there is currently a bug somewhere in
-            # right_hand_split() that is causing brackets to not be tracked
-            # properly by a shared BracketTracker.
-            append_leaves(new_line, line, LL[: string_idx - 1], preformatted=True)
-
-        string_leaf = Leaf(token.STRING, LL[string_idx].value)
-        LL[string_idx - 1].remove()
-        replace_child(LL[string_idx], string_leaf)
-        new_line.append(string_leaf)
-
-        append_leaves(
-            new_line, line, LL[string_idx + 1 : rpar_idx] + LL[rpar_idx + 1 :]
-        )
 
-        LL[rpar_idx].remove()
+        previous_idx = -1
+        # We need to sort the indices, since string_idx and its matching
+        # rpar_idx may not come in order, e.g. in
+        # `("outer" % ("inner".join(items)))`, the "inner" string's
+        # string_idx is smaller than "outer" string's rpar_idx.
+        for idx in sorted(string_and_rpar_indices):
+            leaf = LL[idx]
+            lpar_or_rpar_idx = idx - 1 if leaf.type == token.STRING else idx
+            append_leaves(new_line, line, LL[previous_idx + 1 : lpar_or_rpar_idx])
+            if leaf.type == token.STRING:
+                string_leaf = Leaf(token.STRING, LL[idx].value)
+                LL[lpar_or_rpar_idx].remove()  # Remove lpar.
+                replace_child(LL[idx], string_leaf)
+                new_line.append(string_leaf)
+            else:
+                LL[lpar_or_rpar_idx].remove()  # This is a rpar.
+
+            previous_idx = idx
 
-        yield Ok(new_line)
+        # Append the leaves after the last idx:
+        append_leaves(new_line, line, LL[idx + 1 :])
+
+        return new_line
 
 
 class BaseStringSplitter(StringTransformer):
@@ -884,7 +1003,12 @@ class BaseStringSplitter(StringTransformer):
         if isinstance(match_result, Err):
             return match_result
 
-        string_idx = match_result.ok()
+        string_indices = match_result.ok()
+        assert len(string_indices) == 1, (
+            f"{self.__class__.__name__} should only find one match at a time, found"
+            f" {len(string_indices)}"
+        )
+        string_idx = string_indices[0]
         vresult = self._validate(line, string_idx)
         if isinstance(vresult, Err):
             return vresult
@@ -1126,6 +1250,30 @@ def fstring_contains_expr(s: str) -> bool:
     return any(iter_fexpr_spans(s))
 
 
+def _toggle_fexpr_quotes(fstring: str, old_quote: str) -> str:
+    """
+    Toggles quotes used in f-string expressions that are `old_quote`.
+
+    f-string expressions can't contain backslashes, so we need to toggle the
+    quotes if the f-string itself will end up using the same quote. We can
+    simply toggle without escaping because, quotes can't be reused in f-string
+    expressions. They will fail to parse.
+
+    NOTE: If PEP 701 is accepted, above statement will no longer be true.
+    Though if quotes can be reused, we can simply reuse them without updates or
+    escaping, once Black figures out how to parse the new grammar.
+    """
+    new_quote = "'" if old_quote == '"' else '"'
+    parts = []
+    previous_index = 0
+    for start, end in iter_fexpr_spans(fstring):
+        parts.append(fstring[previous_index:start])
+        parts.append(fstring[start:end].replace(old_quote, new_quote))
+        previous_index = end
+    parts.append(fstring[previous_index:])
+    return "".join(parts)
+
+
 class StringSplitter(BaseStringSplitter, CustomSplitMapMixin):
     """
     StringTransformer that splits "atom" strings (i.e. strings which exist on
@@ -1218,10 +1366,17 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin):
         if is_valid_index(idx):
             return TErr("This line does not end with a string.")
 
-        return Ok(string_idx)
+        return Ok([string_idx])
 
-    def do_transform(self, line: Line, string_idx: int) -> Iterator[TResult[Line]]:
+    def do_transform(
+        self, line: Line, string_indices: List[int]
+    ) -> Iterator[TResult[Line]]:
         LL = line.leaves
+        assert len(string_indices) == 1, (
+            f"{self.__class__.__name__} should only find one match at a time, found"
+            f" {len(string_indices)}"
+        )
+        string_idx = string_indices[0]
 
         QUOTE = LL[string_idx].value[-1]
 
@@ -1359,9 +1514,14 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin):
             # prefix, and the current custom split did NOT originally use a
             # prefix...
             if (
-                next_value != self._normalize_f_string(next_value, prefix)
-                and use_custom_breakpoints
+                use_custom_breakpoints
                 and not csplit.has_prefix
+                and (
+                    # `next_value == prefix + QUOTE` happens when the custom
+                    # split is an empty string.
+                    next_value == prefix + QUOTE
+                    or next_value != self._normalize_f_string(next_value, prefix)
+                )
             ):
                 # Then `csplit.break_idx` will be off by one after removing
                 # the 'f' prefix.
@@ -1704,7 +1864,7 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
                             " resultant line would still be over the specified line"
                             " length and can't be split further by StringSplitter."
                         )
-            return Ok(string_idx)
+            return Ok([string_idx])
 
         return TErr("This line does not contain any non-atomic strings.")
 
@@ -1860,7 +2020,7 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
 
             for i, leaf in enumerate(LL):
                 # We MUST find a colon, it can either be dict's or lambda's colon...
-                if leaf.type == token.COLON:
+                if leaf.type == token.COLON and i < len(LL) - 1:
                     idx = i + 2 if is_empty_par(LL[i + 1]) else i + 1
 
                     # That colon MUST be followed by a string...
@@ -1881,8 +2041,15 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
 
         return None
 
-    def do_transform(self, line: Line, string_idx: int) -> Iterator[TResult[Line]]:
+    def do_transform(
+        self, line: Line, string_indices: List[int]
+    ) -> Iterator[TResult[Line]]:
         LL = line.leaves
+        assert len(string_indices) == 1, (
+            f"{self.__class__.__name__} should only find one match at a time, found"
+            f" {len(string_indices)}"
+        )
+        string_idx = string_indices[0]
 
         is_valid_index = is_valid_index_factory(LL)
         insert_str_child = insert_str_child_factory(LL[string_idx])