Re: @math{-} does not produce a minus sign in Info

[Vincent Lefevre]

On 2022-10-25 14:59:01 +0100, Gavin Smith wrote:
> On Tue, Oct 25, 2022 at 03:28:33PM +0200, Vincent Lefevre wrote:
> > With some fonts, such as DejaVu Sans Mono, the ASCII - is a very narrow
> > dash (e.g. 2×4 pixels), which is fine when used as an hyphen, but looks
> > too much like a dot in math expressions. With this font, the minus sign
> > is larger (2×8 pixels), thus easier to read in math expressions.
> 
> Not much can be expected in terms of typographical quality for Info
> output, so I don't see this as a problem for Info.

Well, if the true Unicode characters were used, typography should
be OK.

> For HTML output, you have the option of using @minus{} instead,

So we are going back to the use of @minus{} as I suggested (I recall
that in the context of simple math formulas, such as "n = −2", the
goal is to use the same text for all outputs).

> or @math{-} with any of the HTML_MATH settings.

The HTML_MATH settings are not OK with the current release.

> > Another reason is to avoid false positives when searching for a minus
> > sign.
> 
> It seems like the opposite would be the case that people will be unable
> to find the minus sign when searching the document because they are
> unable to type it in on their keyboards.

Well, that's a potential issue with all non-ASCII characters. This
is not specific to the true minus sign. The solution is to make the
Info reader handle such cases:
  * Make an ASCII character also match similar non-ASCII ones. This
    solution is implemented in Firefox, for instance (and it can be
    disabled to get exact matches).
  * Alternatively, transcode everything to ASCII. This can already
    be done by running info with LC_CTYPE=C.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)