Re: [TCLCORE] Extending unicode literals past the BMP

[Larry M. <lm...@bi...>]

On Sun, Jul 31, 2011 at 09:18:50AM +1000, Steve Bennett wrote:
> A recent post to c.l.t encouraged me to add support for Jim Tcl for unicode
> literals (\uNNNN) past the BMP. Non-literals are easy because Jim uses
> pure utf-8 internally, but with literals we have the problem with
> situations like this:
> 
>  set x "\u2702b"
> 
> Currently \u can accept up to 4 hex digits, but extending past the BMP
> requires that we accept more. In this case do we have one character or two?
> 
> Two options are:
> 
> 1. Add \U which allows up to 6 hex digits. e.g.
> 
>  set x "\U2702b"
> 
> 2. Allow braced \u escapes. e.g.
> 
>  set x "\u{2702b}"
> 
> One day Tcl may face the same issue, so I would be interested in thoughts
> from anyone here. I am leaning towards option 2.

Option 1, if you do it, should be a fixed number of digits so you can parse
it.

I like option 2 myself.
-- 
---
Larry McVoy                lm at bitmover.com           http://www.bitkeeper.com