Re: Bidirectional text and URLs

[Eli Zaretskii]

> Date: Fri, 05 Dec 2014 17:44:37 -0500
> From: Richard Stallman <address@hidden>
> CC: address@hidden, address@hidden
> 
>   > > One use of disabling bidi is that you'll see what the strange URL
>   > > really consists of.
> 
>   > We already have a better solution for that, I just added yesterday the
>   > infrastructure that enables such a solution.
> 
> Could you tell me what that solution is?  I'm concerned that we
> may be miscommunicating again.

I meant this primitive:

  (bidi-find-overridden-directionality FROM TO &optional OBJECT)

  Return position between FROM and TO where directionality was overridden.

  This function returns the first character position in the specified
  region of OBJECT where there is a character whose `bidi-class' property
  is `L', but which was forced to display as `R' by a directional
  override, and likewise with characters whose `bidi-class' is `R'
  or `AL' that were forced to display as `L'.

  If no such character is found, the function returns nil.

  OBJECT is a Lisp string or buffer to search for overridden
  directionality, and defaults to the current buffer if nil or omitted.
  OBJECT can also be a window, in which case the function will search
  the buffer displayed in that window.  Passing the window instead of
  a buffer is preferable when the buffer is displayed in some window,
  because this function will then be able to correctly account for
  window-specific overlays, which can affect the results.

  Strong directional characters `L', `R', and `AL' can have their
  intrinsic directionality overridden by directional override
  control characters RLO (u+202e) and LRO (u+202d).  See the
  function `get-char-code-property' for a way to inquire about
  the `bidi-class' property of a character.