import re
import unicodedata
import functools
from .types import CharBuffer, CharWidths
from .trace import trace
ANSI_ESCAPE_SEQUENCE = re.compile(r"\x1b\[[ -@]*[A-~]")
ZERO_WIDTH_BRACKET = re.compile(r"\x01.*?\x02")
ZERO_WIDTH_TRANS = str.maketrans({"\x01": "", "\x02": ""})
@functools.cache
def str_width(c: str) -> int:
if ord(c) < 128:
return 1
# gh-139246 for zero-width joiner and combining characters
if unicodedata.combining(c):
return 0
category = unicodedata.category(c)
if category == "Cf" and c != "\u00ad":
return 0
w = unicodedata.east_asian_width(c)
if w in ("N", "Na", "H", "A"):
return 1
return 2
def wlen(s: str) -> int:
if len(s) == 1 and s != "\x1a":
return str_width(s)
length = sum(str_width(i) for i in s)
# remove lengths of any escape sequences
sequence = ANSI_ESCAPE_SEQUENCE.findall(s)
ctrl_z_cnt = s.count("\x1a")
return length - sum(len(i) for i in sequence) + ctrl_z_cnt
def unbracket(s: str, including_content: bool = False) -> str:
r"""Return `s` with \001 and \002 characters removed.
If `including_content` is True, content between \001 and \002 is also
stripped.
"""
if including_content:
return ZERO_WIDTH_BRACKET.sub("", s)
return s.translate(ZERO_WIDTH_TRANS)
def disp_str(buffer: str) -> tuple[CharBuffer, CharWidths]:
r"""Decompose the input buffer into a printable variant.
Returns a tuple of two lists:
- the first list is the input buffer, character by character;
- the second list is the visible width of each character in the input
buffer.
Examples:
>>> utils.disp_str("a = 9")
(['a', ' ', '=', ' ', '9'], [1, 1, 1, 1, 1])
"""
chars: CharBuffer = []
char_widths: CharWidths = []
if not buffer:
return chars, char_widths
for c in buffer:
if c == "\x1a": # CTRL-Z on Windows
chars.append(c)
char_widths.append(2)
elif ord(c) < 128:
chars.append(c)
char_widths.append(1)
elif unicodedata.category(c).startswith("C"):
c = r"\u%04x" % ord(c)
chars.append(c)
char_widths.append(len(c))
else:
chars.append(c)
char_widths.append(str_width(c))
trace("disp_str({buffer}) = {s}, {b}", buffer=repr(buffer), s=chars, b=char_widths)
return chars, char_widths
