--- /dev/null
+"""
+Simple formatting on strings. Further string formatting code is in trans.py.
+"""
+
+import regex as re
+import sys
+from typing import List, Pattern
+
+
+STRING_PREFIX_CHARS = "furbFURB" # All possible string prefix characters.
+
+
+def sub_twice(regex: Pattern[str], replacement: str, original: str) -> str:
+ """Replace `regex` with `replacement` twice on `original`.
+
+ This is used by string normalization to perform replaces on
+ overlapping matches.
+ """
+ return regex.sub(replacement, regex.sub(replacement, original))
+
+
+def has_triple_quotes(string: str) -> bool:
+ """
+ Returns:
+ True iff @string starts with three quotation characters.
+ """
+ raw_string = string.lstrip(STRING_PREFIX_CHARS)
+ return raw_string[:3] in {'"""', "'''"}
+
+
+def lines_with_leading_tabs_expanded(s: str) -> List[str]:
+ """
+ Splits string into lines and expands only leading tabs (following the normal
+ Python rules)
+ """
+ lines = []
+ 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)
+ if match:
+ first_non_whitespace_idx = match.start(1)
+
+ lines.append(
+ line[:first_non_whitespace_idx].expandtabs()
+ + line[first_non_whitespace_idx:]
+ )
+ else:
+ lines.append(line)
+ return lines
+
+
+def fix_docstring(docstring: str, prefix: str) -> str:
+ # https://www.python.org/dev/peps/pep-0257/#handling-docstring-indentation
+ if not docstring:
+ return ""
+ lines = lines_with_leading_tabs_expanded(docstring)
+ # Determine minimum indentation (first line doesn't count):
+ indent = sys.maxsize
+ for line in lines[1:]:
+ stripped = line.lstrip()
+ if stripped:
+ indent = min(indent, len(line) - len(stripped))
+ # Remove indentation (first line is special):
+ trimmed = [lines[0].strip()]
+ if indent < sys.maxsize:
+ last_line_idx = len(lines) - 2
+ for i, line in enumerate(lines[1:]):
+ stripped_line = line[indent:].rstrip()
+ if stripped_line or i == last_line_idx:
+ trimmed.append(prefix + stripped_line)
+ else:
+ trimmed.append("")
+ return "\n".join(trimmed)
+
+
+def get_string_prefix(string: str) -> str:
+ """
+ Pre-conditions:
+ * assert_is_leaf_string(@string)
+
+ Returns:
+ @string's prefix (e.g. '', 'r', 'f', or 'rf').
+ """
+ assert_is_leaf_string(string)
+
+ prefix = ""
+ prefix_idx = 0
+ while string[prefix_idx] in STRING_PREFIX_CHARS:
+ prefix += string[prefix_idx]
+ prefix_idx += 1
+
+ return prefix
+
+
+def assert_is_leaf_string(string: str) -> None:
+ """
+ Checks the pre-condition that @string has the format that you would expect
+ of `leaf.value` where `leaf` is some Leaf such that `leaf.type ==
+ token.STRING`. A more precise description of the pre-conditions that are
+ checked are listed below.
+
+ Pre-conditions:
+ * @string starts with either ', ", <prefix>', or <prefix>" where
+ `set(<prefix>)` is some subset of `set(STRING_PREFIX_CHARS)`.
+ * @string ends with a quote character (' or ").
+
+ Raises:
+ AssertionError(...) if the pre-conditions listed above are not
+ satisfied.
+ """
+ dquote_idx = string.find('"')
+ squote_idx = string.find("'")
+ if -1 in [dquote_idx, squote_idx]:
+ quote_idx = max(dquote_idx, squote_idx)
+ else:
+ quote_idx = min(squote_idx, dquote_idx)
+
+ assert (
+ 0 <= quote_idx < len(string) - 1
+ ), f"{string!r} is missing a starting quote character (' or \")."
+ assert string[-1] in (
+ "'",
+ '"',
+ ), f"{string!r} is missing an ending quote character (' or \")."
+ assert set(string[:quote_idx]).issubset(
+ set(STRING_PREFIX_CHARS)
+ ), 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)
+ 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", "")
+ return f"{new_prefix}{match.group(2)}"
+
+
+def normalize_string_quotes(s: str) -> str:
+ """Prefer double quotes but only if it doesn't cause more escaping.
+
+ Adds or removes backslashes as appropriate. Doesn't parse and fix
+ strings nested in f-strings.
+ """
+ value = s.lstrip(STRING_PREFIX_CHARS)
+ if value[:3] == '"""':
+ return s
+
+ elif value[:3] == "'''":
+ orig_quote = "'''"
+ new_quote = '"""'
+ elif value[0] == '"':
+ orig_quote = '"'
+ new_quote = "'"
+ else:
+ orig_quote = "'"
+ new_quote = '"'
+ first_quote_pos = s.find(orig_quote)
+ if first_quote_pos == -1:
+ 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}")
+ body = s[first_quote_pos + len(orig_quote) : -len(orig_quote)]
+ if "r" in prefix.casefold():
+ if unescaped_new_quote.search(body):
+ # There's at least one unescaped new_quote in this raw string
+ # so converting is impossible
+ return s
+
+ # Do not introduce or remove backslashes in raw strings
+ new_body = body
+ else:
+ # remove unnecessary escapes
+ new_body = sub_twice(escaped_new_quote, rf"\1\2{new_quote}", body)
+ if body != new_body:
+ # Consider the string without unnecessary escapes as the original
+ body = new_body
+ s = f"{prefix}{orig_quote}{body}{orig_quote}"
+ new_body = sub_twice(escaped_orig_quote, rf"\1\2{orig_quote}", new_body)
+ new_body = sub_twice(unescaped_new_quote, rf"\1\\{new_quote}", new_body)
+ if "f" in prefix.casefold():
+ matches = re.findall(
+ r"""
+ (?:(?<!\{)|^)\{ # start of the string or a non-{ followed by a single {
+ ([^{].*?) # contents of the brackets except if begins with {{
+ \}(?:(?!\})|$) # A } followed by end of the string or a non-}
+ """,
+ new_body,
+ re.VERBOSE,
+ )
+ for m in matches:
+ if "\\" in str(m):
+ # Do not introduce backslashes in interpolated expressions
+ return s
+
+ if new_quote == '"""' and new_body[-1:] == '"':
+ # edge case:
+ new_body = new_body[:-1] + '\\"'
+ orig_escape_count = body.count("\\")
+ new_escape_count = new_body.count("\\")
+ if new_escape_count > orig_escape_count:
+ return s # Do not introduce more escaping
+
+ if new_escape_count == orig_escape_count and orig_quote == '"':
+ return s # Prefer double quotes
+
+ return f"{prefix}{new_quote}{new_body}{new_quote}"
projects / etc / vim.git / blobdiff