X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/117891878e5be4d6b771ae5de299e51b679cea27..abdc31cd4fb6cf88339f8ade0adf9c5356a95aa3:/src/black/trans.py diff --git a/src/black/trans.py b/src/black/trans.py index d918ef1..01aa80e 100644 --- a/src/black/trans.py +++ b/src/black/trans.py @@ -4,7 +4,7 @@ String transformers that can split and merge strings. from abc import ABC, abstractmethod from collections import defaultdict from dataclasses import dataclass -import regex as re +import re from typing import ( Any, Callable, @@ -24,9 +24,9 @@ from typing import ( import sys if sys.version_info < (3, 8): - from typing_extensions import Final + from typing_extensions import Literal, Final else: - from typing import Final + from typing import Literal, Final from mypy_extensions import trait @@ -71,6 +71,88 @@ def TErr(err_msg: str) -> Err[CannotTransform]: return Err(cant_transform) +def hug_power_op(line: Line, features: Collection[Feature]) -> Iterator[Line]: + """A transformer which normalizes spacing around power operators.""" + + # Performance optimization to avoid unnecessary Leaf clones and other ops. + for leaf in line.leaves: + if leaf.type == token.DOUBLESTAR: + break + else: + raise CannotTransform("No doublestar token was found in the line.") + + def is_simple_lookup(index: int, step: Literal[1, -1]) -> bool: + # Brackets and parentheses indicate calls, subscripts, etc. ... + # basically stuff that doesn't count as "simple". Only a NAME lookup + # or dotted lookup (eg. NAME.NAME) is OK. + if step == -1: + disallowed = {token.RPAR, token.RSQB} + else: + disallowed = {token.LPAR, token.LSQB} + + while 0 <= index < len(line.leaves): + current = line.leaves[index] + if current.type in disallowed: + return False + if current.type not in {token.NAME, token.DOT} or current.value == "for": + # If the current token isn't disallowed, we'll assume this is simple as + # only the disallowed tokens are semantically attached to this lookup + # expression we're checking. Also, stop early if we hit the 'for' bit + # of a comprehension. + return True + + index += step + + return True + + def is_simple_operand(index: int, kind: Literal["base", "exponent"]) -> bool: + # An operand is considered "simple" if's a NAME, a numeric CONSTANT, a simple + # lookup (see above), with or without a preceding unary operator. + start = line.leaves[index] + if start.type in {token.NAME, token.NUMBER}: + return is_simple_lookup(index, step=(1 if kind == "exponent" else -1)) + + if start.type in {token.PLUS, token.MINUS, token.TILDE}: + if line.leaves[index + 1].type in {token.NAME, token.NUMBER}: + # step is always one as bases with a preceding unary op will be checked + # for simplicity starting from the next token (so it'll hit the check + # above). + return is_simple_lookup(index + 1, step=1) + + return False + + leaves: List[Leaf] = [] + should_hug = False + for idx, leaf in enumerate(line.leaves): + new_leaf = leaf.clone() + if should_hug: + new_leaf.prefix = "" + should_hug = False + + should_hug = ( + (0 < idx < len(line.leaves) - 1) + and leaf.type == token.DOUBLESTAR + and is_simple_operand(idx - 1, kind="base") + and line.leaves[idx - 1].value != "lambda" + and is_simple_operand(idx + 1, kind="exponent") + ) + 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, + ) + + class StringTransformer(ABC): """ An implementation of the Transformer protocol that relies on its @@ -283,7 +365,7 @@ class StringMerger(StringTransformer, CustomSplitMapMixin): is_valid_index = is_valid_index_factory(LL) - for (i, leaf) in enumerate(LL): + for i, leaf in enumerate(LL): if ( leaf.type == token.STRING and is_valid_index(i + 1) @@ -453,7 +535,7 @@ class StringMerger(StringTransformer, CustomSplitMapMixin): # with 'f'... if "f" in prefix and "f" not in next_prefix: # Then we must escape any braces contained in this substring. - SS = re.subf(r"(\{|\})", "{1}{1}", SS) + SS = re.sub(r"(\{|\})", r"\1\1", SS) NSS = make_naked(SS, next_prefix) @@ -488,7 +570,7 @@ class StringMerger(StringTransformer, CustomSplitMapMixin): # Build the final line ('new_line') that this method will later return. new_line = line.clone() - for (i, leaf) in enumerate(LL): + for i, leaf in enumerate(LL): if i == string_idx: new_line.append(string_leaf) @@ -609,7 +691,7 @@ class StringParenStripper(StringTransformer): is_valid_index = is_valid_index_factory(LL) - for (idx, leaf) in enumerate(LL): + for idx, leaf in enumerate(LL): # Should be a string... if leaf.type != token.STRING: continue @@ -942,6 +1024,57 @@ class BaseStringSplitter(StringTransformer): return max_string_length +def iter_fexpr_spans(s: str) -> Iterator[Tuple[int, int]]: + """ + Yields spans corresponding to expressions in a given f-string. + Spans are half-open ranges (left inclusive, right exclusive). + Assumes the input string is a valid f-string, but will not crash if the input + string is invalid. + """ + stack: List[int] = [] # our curly paren stack + i = 0 + while i < len(s): + if s[i] == "{": + # if we're in a string part of the f-string, ignore escaped curly braces + if not stack and i + 1 < len(s) and s[i + 1] == "{": + i += 2 + continue + stack.append(i) + i += 1 + continue + + if s[i] == "}": + if not stack: + i += 1 + continue + j = stack.pop() + # we've made it back out of the expression! yield the span + if not stack: + yield (j, i + 1) + i += 1 + continue + + # if we're in an expression part of the f-string, fast forward through strings + # note that backslashes are not legal in the expression portion of f-strings + if stack: + delim = None + if s[i : i + 3] in ("'''", '"""'): + delim = s[i : i + 3] + elif s[i] in ("'", '"'): + delim = s[i] + if delim: + i += len(delim) + while i < len(s) and s[i : i + len(delim)] != delim: + i += 1 + i += len(delim) + continue + i += 1 + + +def fstring_contains_expr(s: str) -> bool: + return any(iter_fexpr_spans(s)) + + class StringSplitter(BaseStringSplitter, CustomSplitMapMixin): """ StringTransformer that splits "atom" strings (i.e. strings which exist on @@ -981,17 +1114,6 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin): """ MIN_SUBSTR_SIZE: Final = 6 - # Matches an "f-expression" (e.g. {var}) that might be found in an f-string. - RE_FEXPR: Final = r""" - (? TMatchResult: LL = line.leaves @@ -1058,8 +1180,8 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin): # contain any f-expressions, but ONLY if the original f-string # contains at least one f-expression. Otherwise, we will alter the AST # of the program. - drop_pointless_f_prefix = ("f" in prefix) and re.search( - self.RE_FEXPR, LL[string_idx].value, re.VERBOSE + drop_pointless_f_prefix = ("f" in prefix) and fstring_contains_expr( + LL[string_idx].value ) first_string_line = True @@ -1299,9 +1421,7 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin): """ if "f" not in get_string_prefix(string).lower(): return - - for match in re.finditer(self.RE_FEXPR, string, re.VERBOSE): - yield match.span() + yield from iter_fexpr_spans(string) def _get_illegal_split_indices(self, string: str) -> Set[Index]: illegal_indices: Set[Index] = set() @@ -1417,7 +1537,7 @@ class StringSplitter(BaseStringSplitter, CustomSplitMapMixin): """ assert_is_leaf_string(string) - if "f" in prefix and not re.search(self.RE_FEXPR, string, re.VERBOSE): + if "f" in prefix and not fstring_contains_expr(string): new_prefix = prefix.replace("f", "") temp = string[len(prefix) :] @@ -1593,7 +1713,7 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin): if parent_type(LL[0]) == syms.assert_stmt and LL[0].value == "assert": is_valid_index = is_valid_index_factory(LL) - for (i, leaf) in enumerate(LL): + for i, leaf in enumerate(LL): # We MUST find a comma... if leaf.type == token.COMMA: idx = i + 2 if is_empty_par(LL[i + 1]) else i + 1 @@ -1631,7 +1751,7 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin): ): is_valid_index = is_valid_index_factory(LL) - for (i, leaf) in enumerate(LL): + for i, leaf in enumerate(LL): # We MUST find either an '=' or '+=' symbol... if leaf.type in [token.EQUAL, token.PLUSEQUAL]: idx = i + 2 if is_empty_par(LL[i + 1]) else i + 1 @@ -1674,7 +1794,7 @@ class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin): if syms.dictsetmaker in [parent_type(LL[0]), parent_type(LL[0].parent)]: is_valid_index = is_valid_index_factory(LL) - for (i, leaf) in enumerate(LL): + for i, leaf in enumerate(LL): # We MUST find a colon... if leaf.type == token.COLON: idx = i + 2 if is_empty_par(LL[i + 1]) else i + 1