RE: Plain text custom fraction input

On 23 Jul 2015, at 18:00, Doug Ewell wrote:

> What you have discovered

Alas, I'd better done a search on the internet prior to solliciting some new advice and feedback, with respect to other peoples' time. Indeed I've "discovered" (quotation) that for myself, but as I learned *after* my last reply yesterday, this "new" (scare quotes!) way of input fractions is already a more or less well established practice. Please read the information with my apologies two e-mails later.
 

> is that under certain circumstances, with
> certain fonts, you can get the visual results you want by using
> characters other than those recommended in the Standard -- by using
> characters simply because they "look right."

This might be the case of the apostrophe too, for which a quotation mark is used for its looking the same. Yesterday I criticized this proceeding when I wrote in the thread “Global apostrophe solution?”:

>> This reflects however a tendency that prioritizes the appearance. In Unicode this tendency is far from being omnipresent, it is surely very marginal in Unicode, and it’s presence is due to the influence of the software industry where that tendency is naturally more widespread, for economical reasons, that is mainly because the demand on usersʼ side has already a component (among others) which handles appearance as a satisfactory good and not asking for more than that a given item looks fine, no matter whatʼs behind...

Really I understand now that for the fractions I suggest to do exactly the same: using characters that are intended to be used as superscripts/subscripts, to represent digits that are numerators/denominators, not superscripts/subscripts. From the beginning on, my view was based solely on appearance, and the samples I provided use only one single font.

>
> This is not plain text encoding, and it is not a matter of Unicode
> failing to consider a particular usage scenario or failing to "complete"
> some part of the Standard. It is about having an incomplete
> understanding of the Unicode Standard.

I'm truly far, very far from knowing thoroughly the least part of the Standard, and often I started mailing while the requested information would have been at hand by simply uplooking TUS... About plain text, I simply know for having read it somewhere, that this is the base purpose of Unicode. Representing fractions as U+2044 is known as a compatibility mapping, equally like representing a superscript as , while (I go on checking my knowledge...) representing a precomposed diacriticized letter as is known as a decomposition mapping. The difference between the two ways of getting the same thing is in plain text. With decomposition we stay in plain text, while compatibility mappings need formatting, thus leaving the field of plain text.

So in fact, what I'm suggesting for fractions, is to use a decomposition rather than a compat mapping. And to use this decomposition scheme to compose arbitrary fractions without leaving plain text. The problem is, as you point it out, that this is *not* defined in the Standard. Therefore a font can be compliant to the Standard without allowing this usage. That is the case of at least *all* monospaced fonts. By contrast, for example combining diacritics work in *all* Unicode compliant fonts if the decomposition mapping is defined. Overlay combining diacritics however sometimes don't work fine. Their usage is not defined in the Standard for decomposition (precomposed letters with overlay diacritics are not decomposed), *because* they don't work always fine. From this we might infer that plain text custom fraction input is not a part of TUS because it doesn't always work fine.

>
> Read, listen, learn.

Thank you for your answer. I've been given the opportunity of learning a certain amount of things by reading the actual replies and by doing some searches in the Archive. I confess however that I'm somewhat unprepared. It's very hard for me to work up all that's required within a useful timelap, unfortunately.

Best regards,

Marcel
 

> Message du 23/07/15 18:10
> De : "Doug Ewell"
> A : "Unicode Mailing List"
> Copie à : "Marcel Schneider"
> Objet : RE: Plain text custom fraction input
>
> Sorry, everyone:
>
> > On the other hand, the harmonization inside the fonts, between super-
> > and subscripts and the numerators and denominators of the precomposed
> > fractions they contain, could be purely esthetical without any idea of
> > using superscripts as numerators, subscripts as denominators. [...]
>
> > The fraction formatting works also when the slash is not a fraction
> > slash but a common slash. [...]
>
> What you have discovered is that under certain circumstances, with
> certain fonts, you can get the visual results you want by using
> characters other than those recommended in the Standard -- by using
> characters simply because they "look right."
>
> This is not plain text encoding, and it is not a matter of Unicode
> failing to consider a particular usage scenario or failing to "complete"
> some part of the Standard. It is about having an incomplete
> understanding of the Unicode Standard.
>
> Read, listen, learn.
>
> --
> Doug Ewell | http://ewellic.org | Thornton, CO 🇺🇸
>
>
>
Received on Fri Jul 24 2015 - 04:25:48 CDT