[perl #128003] [LTA ERROR] forgetting "token" next to a rule with a dot in it gives confusing error

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# New Ticket Created by  Zoffix Znet 
# Please include the string:  [perl #128003]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=128003 >


Not sure if there's any way to improve this, but I've spent some time on this 
error, looking at the wrong place. The issue is not the dot, nor concatenation, 
but the missing "token" keyword before TOP:

<ZoffixWin> m: grammar { TOP { . } }
<camelia> rakudo-moar ce5dc0: OUTPUT«===SORRY!=== Error while compiling 
/tmp/jikmv2xskv␤Unsupported use of . to concatenate strings; in Perl 6 please 
use ~␤at /tmp/jikmv2xskv:1␤------> grammar { TOP { . ⏏} }␤»