Semantic predicates require space?

[Paul Hilfinger]

Akim,

In commit 68ac70bc7bf365fa17bd6d7ea597fa0a05488b8d, in scan-gram.l, I
see this change:

-  {directive} {
+  "%"{id}|"%"{notletter}([[:graph:]])+ {
     complain_at (*loc, _("invalid directive: %s"), quote (yytext));
   }

This has the effect that one must write semantic expressions as

     %? { expression }

rather than

     %?{ expression }

Was this intentional?

Paul Hilfinger