[XeTeX] XeTeX maintenance

[Douglas McKenna]

Ross Moore wrote -

> On 27/04/2015, at 10:05 AM, Douglas McKenna wrote:
> 
>> Given that the number of TeX input files using ^^u is likely miniscule, and the number of those that follow the ^^u or ^^U with four or six hex digits is even smaller, it seemed like a worthwhile benefit vs. cost, compatibility-wise.  Maybe there's something I've not thought out well.
> 
> For user-input files, then yes it is probably very small.
> But such constructions figure to be used a lot within package sources
> --- precisely to create macros that shield users from the syntax.
> 
> For example, try in a terminal:
> 
>   grep "\^\^\^\^" `kpsewhich unicode-math.dtx` | wc -l
>  
> There are 160 lines of input and/or macro definitions.
> (four of these use ^^^^^ )
> Doubtless packages supporting other languages are similar.

Well, yes, but that's a separate issue.  Nothing says that both syntaxes can't be supported in an engine to maximize compatibility with both older packages and newer user input.

Regardless, as the future unfolds, more and more input files are going to be UTF-8 text files, and the need to escape 4-digit or 6-digit Unicode code points in a pure ASCII environment is going to gradually disappear.

Doug McKenna