X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/00e7e12a3a412ea386806d5d4eeaed345e912940..4bee9cca5553c55493203822b5a112ec5216bc74:/src/black/strings.py diff --git a/src/black/strings.py b/src/black/strings.py index 80f588f..9d0e2eb 100644 --- a/src/black/strings.py +++ b/src/black/strings.py @@ -2,12 +2,22 @@ Simple formatting on strings. Further string formatting code is in trans.py. """ -import regex as re +import re import sys +from functools import lru_cache from typing import List, Pattern +if sys.version_info < (3, 8): + from typing_extensions import Final +else: + from typing import Final -STRING_PREFIX_CHARS = "furbFURB" # All possible string prefix characters. + +STRING_PREFIX_CHARS: Final = "furbFURB" # All possible string prefix characters. +STRING_PREFIX_RE: Final = re.compile( + r"^([" + STRING_PREFIX_CHARS + r"]*)(.*)$", re.DOTALL +) +FIRST_NON_WHITESPACE_RE: Final = re.compile(r"\s*\t+\s*(\S)") def sub_twice(regex: Pattern[str], replacement: str, original: str) -> str: @@ -37,7 +47,7 @@ def lines_with_leading_tabs_expanded(s: str) -> List[str]: for line in s.splitlines(): # Find the index of the first non-whitespace character after a string of # whitespace that includes at least one tab - match = re.match(r"\s*\t+\s*(\S)", line) + match = FIRST_NON_WHITESPACE_RE.match(line) if match: first_non_whitespace_idx = match.start(1) @@ -128,20 +138,32 @@ def assert_is_leaf_string(string: str) -> None: ), f"{set(string[:quote_idx])} is NOT a subset of {set(STRING_PREFIX_CHARS)}." -def normalize_string_prefix(s: str, remove_u_prefix: bool = False) -> str: - """Make all string prefixes lowercase. - - If remove_u_prefix is given, also removes any u prefix from the string. - """ - match = re.match(r"^([" + STRING_PREFIX_CHARS + r"]*)(.*)$", s, re.DOTALL) +def normalize_string_prefix(s: str) -> str: + """Make all string prefixes lowercase.""" + match = STRING_PREFIX_RE.match(s) assert match is not None, f"failed to match string {s!r}" orig_prefix = match.group(1) - new_prefix = orig_prefix.replace("F", "f").replace("B", "b").replace("U", "u") - if remove_u_prefix: - new_prefix = new_prefix.replace("u", "") + new_prefix = ( + orig_prefix.replace("F", "f") + .replace("B", "b") + .replace("U", "") + .replace("u", "") + ) + + # Python syntax guarantees max 2 prefixes and that one of them is "r" + if len(new_prefix) == 2 and "r" != new_prefix[0].lower(): + new_prefix = new_prefix[::-1] return f"{new_prefix}{match.group(2)}" +# Re(gex) does actually cache patterns internally but this still improves +# performance on a long list literal of strings by 5-9% since lru_cache's +# caching overhead is much lower. +@lru_cache(maxsize=64) +def _cached_compile(pattern: str) -> Pattern[str]: + return re.compile(pattern) + + def normalize_string_quotes(s: str) -> str: """Prefer double quotes but only if it doesn't cause more escaping. @@ -166,9 +188,9 @@ def normalize_string_quotes(s: str) -> str: return s # There's an internal error prefix = s[:first_quote_pos] - unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}") - escaped_new_quote = re.compile(rf"([^\\]|^)\\((?:\\\\)*){new_quote}") - escaped_orig_quote = re.compile(rf"([^\\]|^)\\((?:\\\\)*){orig_quote}") + unescaped_new_quote = _cached_compile(rf"(([^\\]|^)(\\\\)*){new_quote}") + escaped_new_quote = _cached_compile(rf"([^\\]|^)\\((?:\\\\)*){new_quote}") + escaped_orig_quote = _cached_compile(rf"([^\\]|^)\\((?:\\\\)*){orig_quote}") body = s[first_quote_pos + len(orig_quote) : -len(orig_quote)] if "r" in prefix.casefold(): if unescaped_new_quote.search(body): @@ -190,9 +212,9 @@ def normalize_string_quotes(s: str) -> str: if "f" in prefix.casefold(): matches = re.findall( r""" - (?:[^{]|^)\{ # start of the string or a non-{ followed by a single { + (?:(?