Re: Math literal colon

[Hans Aberg <haberg-1@telia.com>]

> On 24 Jul 2015, at 21:58, Hans Hagen <pragma@wxs.nl> wrote:
> 
> On 7/24/2015 6:57 PM, Hans Aberg wrote:

>>>> The Unicode monospace characters were added by mistake, because in computer science, style does not affect semantics, as it does math. Looking into old computer science books, they do not have monospace, and a I recall a Pascal compiler on Mac OS 9 that used styled, non-monospace fonts. So a monospace font may not be strictly necessary, though current UTF-8 plain text does not look good. In Xcode, part of the reason is that one cannot choose font per Unicode code point segments.
>>> 
>>> we're not talking of the monospace math alphabet (those are already covered but the fonts) but about a monospaced font for editing and verbatim (handy for manuals explaining math typesetting)
>> 
>> Right. But it was added because it is popular in computer science to use a monospace font, though not strictly necessary from the semantic point of view.
> 
> one extra alphabet is not putting that much of a burden on tex;

It is more a curiosity, the reason they were added. It might be useful some day, say using bold monospace for keywords in programming languages.

It reminds me, in math one can use the idea that upright for constants, italic for variables. But I think in LaTeX packages mathtools and/or unicode-math, it is difficult to do that in UTF-8, because the somehow translates them to italic.

And the Unicode sans-serif mathematical styles aren’t really semantic either from the mathematical point of view, but there is a technical standard to set tensors in sans-serif, and perhaps were added because of that. Physics books seem to be bit chaotic here. In pure math, it is all serif.

> let's hope math coders don't start using the many emoticons and alike that unicode provides

From the Unicode list discussion, I think there was a fairly large number of additional symbols the poster wanted to be added. But it took a long time, via STIX, the get the current ones usable.

But as you note, any character could be in principle be used. That is how many started off.

>> So it makes me think that, instead of a monospace font for all the math characters, one  might switch to a variable-width font in the input code, as actuallye been the case in the past.
> 
> which is actually rather inconvenient for entering tables (and i'd also never use it for programming)

Indeed, but that is the only use. The obsession in computer code to align vertically.

>> All that monospace tabbing will break, that is for sure.
> 
> right and proportial makes debugging hard (and how about blockwise copying)

So possibly, there should be some replacement when using a variable width font.

For the ASCII tabbing, the tab character was originally typically interpreted as being 8 spaces wide, but that is too much for computer code with higher indentation levels. So people switched using spaces instead, successively shrinking down to 2 spaces instead of tab, which is what I use.

Unicode has a number of tab characters, but haven’t seen them in use.


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