def _PromptLen(prompt_str):
"""Ignore all characters between \x01 and \x02 and handle unicode characters.
In particular, the display width of a string may be different from either the
number of bytes or the number of unicode characters.
Additionally, if there are multiple lines in the prompt, only give the length of the last line."""
escaped = False
display_str = ""
for c in prompt_str:
if c == '\x01':
escaped = True
elif c == '\x02':
escaped = False
elif not escaped:
display_str += c
last_line = display_str.split('\n')[-1]
try:
width = libc.wcswidth(last_line)
# en_US.UTF-8 locale missing, just return the number of bytes
except (SystemError, UnicodeError):
return len(display_str)
if width == -1:
return len(display_str)
return width
def testWcsWidth(self):
self.assertEqual(1, libc.wcswidth("▶️"))
self.assertEqual(28, libc.wcswidth("(osh) ~/.../unchanged/oil ▶️ "))
self.assertEqual(2, libc.wcswidth("→ "))
self.assertRaises(UnicodeError, libc.wcswidth, "\xfe")
