Re: New rc snapshot, includes "the equals hack"

["Smarasderagd" <smarry@vex.net>]

Tim Goodwin <tjg@star.le.ac.uk> writes:
>A new, and possibly controversial, rc development snapshot is available
>from the usual place.
>
>    http://www.star.le.ac.uk/~tjg/rc/snap/rc-1.6s20000811.tar.gz
>
>There are a few minor bug fixes, and the addition of the `-I' flag
>from the Plan9 rc (the opposite of `-i': this shell is definitely not
>interactive).  See the full list of changes since the last beta at the
>end of this message.
>
>In addition, this snapshot includes a cunning patch by Thomas Nordin
>that permits `=' to appear, unquoted, outside assignments.  For ease of
>reference, I'm calling this "the equals hack", where the word "hack" is
>not intended to have any pejorative connotations...
>
>The equals hack, which in fact was just a one line addition to the
>grammar, effectively makes `=' stand for `^'='^' (when it's not an
>assignment).  The slightly surprising feature of this is that `='
>swallows whitespace around it.
>
>    ; echo a = b
>    a=b
>
>Apart from that, everything works as you would expect.

Well, I suppose expr's '=' operator isn't much of an issue, and the '>='
and '<=' operators need to be quoted anyway (I think.)  Make runs with
null assignments to makefile variables would still not work right, though.

make Q= target

turns into

make Q=target

Putting the Q= at the end results in a syntax error due to the trailing
implicit caret, and you'll run into this problem with a trailing =
anywhere.  I'd rather have a fix that works completely, or just go on
quoting things as I have been.