Re: what is the point of overlay-arrow-string?

[Richard Stallman]

    > All of the source in Emacs sets this to "=>".  What is the
    > difference?  Can one display anything other than an arrow?

    Not at this time, I think.  The bitmaps displayed in the fringe are
    hard-coded in the C code.

On a tty, the value of overlay-arrow-string is still used.
I think the right thing to do on X is to check whether the
overlay-arrow-string is "=>", and if so, use the fringe icon;
otherwise, display overlay-arrow-string in the old-fashioned way.