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; * src/character.c (Fstring_width, Fchar_width): Doc fixes.

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This commit is contained in:
Eli Zaretskii 2023-07-30 20:10:54 +03:00
parent 1198cdb556
commit bf83fdba9e
1 changed files with 22 additions and 13 deletions
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35
src/character.c
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@ -260,8 +260,12 @@ char_width (int c, struct Lisp_Char_Table *dp)
DEFUN ("char-width", Fchar_width, Schar_width, 1, 1, 0,
doc: /* Return width of CHAR when displayed in the current buffer.
The width is measured by how many columns it occupies on the screen.
doc: /* Return width of CHAR in columns when displayed in the current buffer.
The width of CHAR is measured by how many columns it will occupy on the screen.
This is based on data in `char-width-table', and ignores the actual
metrics of the character's glyph as determined by its font.
If the display table in effect replaces CHAR on display with
something else, the function returns the width of the replacement.
Tab is taken to occupy `tab-width' columns.
usage: (char-width CHAR) */)
(Lisp_Object ch)
@ -457,20 +461,25 @@ lisp_string_width (Lisp_Object string, ptrdiff_t from, ptrdiff_t to,
}
DEFUN ("string-width", Fstring_width, Sstring_width, 1, 3, 0,
doc: /* Return width of STRING when displayed in the current buffer.
Width is measured by how many columns it occupies on the screen.
doc: /* Return width of STRING in columns when displayed in the current buffer.
Width of STRING is measured by how many columns it will occupy on the screen.
Optional arguments FROM and TO specify the substring of STRING to
consider, and are interpreted as in `substring'.
When calculating width of a multibyte character in STRING,
only the base leading-code is considered; the validity of
the following bytes is not checked. Tabs in STRING are always
taken to occupy `tab-width' columns. The effect of faces and fonts
used for non-Latin and other unusual characters (such as emoji) is
ignored as well, as are display properties and invisible text.
For these reasons, the results are not generally reliable;
for accurate dimensions of text as it will be displayed,
use `string-pixel-width' or `window-text-pixel-size' instead.
Width of each character in STRING is generally taken according to
`char-width', but character compositions and the display table in
effect are taken into consideration.
Tabs in are always taken to occupy `tab-width' columns, although they
might take fewer columns depending on the column where they begin.
The effect of faces and fonts, including fonts used for non-Latin and
other unusual characters, such as emoji, is ignored as well, as are
display properties and invisible text.
For these reasons, the results are just an approximation, especially
on GUI frames; for accurate dimensions of text as it will be
displayed, use `string-pixel-width' or `window-text-pixel-size'
instead.
usage: (string-width STRING &optional FROM TO) */)
(Lisp_Object str, Lisp_Object from, Lisp_Object to)
{