RE: tabulated-list sort icon is reversed

[Drew Adams <drew.adams@oracle.com>]

> > There actually is an icon that is unambiguous: the "a-z" or "z-a" one:
> 
> I'd actually prefer it to be 0-9 rather a-z (for non-latin-script
> users), but yes, this is a fairly clear choice.  

1. Neither is great, IMO. The icon should express low-to-high or small-to-large in a _general_ way, and not suggest either an alphabetic or a numeric order.

What do you do with a date column whose values might be any ISO date format? Assuming that the actual sorting is by date (not its representation), neither a-z nor 0-9 suggests what's happening.

2.  Personally, I don't see the difference between this proposal:

   _
  ___
 _____
_______

and a triangle with vertex on top (like ^). The same ambiguity arises:
Does it represent the current sort order (low-to-high / small-to-large)?
Or does it represent the new sort order you'll get if you use that button?

IIUC, the MS Windows approach (for column-sort indicators) is to reflect the current sort order, the same way that a bold or underlined column header indicates that the column is selected (current).

And apparently other, non-Windows contexts take the approach that the icon represents the new order you'll get if you click the icon.

How does the proposed sequence of lines of increasing/decreasing length solve the problem of ambiguity?