stri_width: Determine the Width of Code Points¶
Description¶
Approximates the number of text columns the ‘cat()’ function should use to print a string with a mono-spaced font.
Usage¶
stri_width(str)
Arguments¶
|
character vector or an object coercible to |
Details¶
The Unicode standard does not formalize the notion of a character width. Roughly based on https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c and the UAX #11 we proceed as follows. The following code points are of width 0:
code points with general category (see stringi-search-charclass)
Me
,Mn
, andCf
),C0
andC1
control codes (general categoryCc
) - for compatibility with thenchar
function,Hangul Jamo medial vowels and final consonants (code points with enumerable property
UCHAR_HANGUL_SYLLABLE_TYPE
equal toU_HST_VOWEL_JAMO
orU_HST_TRAILING_JAMO
; note that applying the NFC normalization with stri_trans_nfc is encouraged),ZERO WIDTH SPACE (U+200B),
Characters with the UCHAR_EAST_ASIAN_WIDTH
enumerable property equal to U_EA_FULLWIDTH
or U_EA_WIDE
are of width 2. SOFT HYPHEN (U+00AD) (for compatibility with nchar
) as well as any other characters have width 1.
Value¶
Returns an integer vector of the same length as str
.
References¶
East Asian Width – Unicode Standard Annex #11, https://www.unicode.org/reports/tr11/
See Also¶
Other length: stri_isempty(), stri_length(), stri_numbytes()
Examples¶
stri_width(LETTERS[1:5])
stri_width(stri_trans_nfkd('\u0105'))
stri_width( # Full-width equivalents of ASCII characters:
stri_enc_fromutf32(as.list(c(0x3000, 0xFF01:0xFF5E)))
)
stri_width(stri_trans_nfkd('\ubc1f')) # includes Hangul Jamo medial vowels and final consonants