The mechanism with the next pointers for tac's was working fine as long as all
tac's were unique by construction. The macro mechanism made it possible for
the same tac to occur twice in the tree. This could lead to an infinite loop.
Now we make explicit copies of the top-level tac. This should fix the problem
caused by the tuple parsing.
A more fundamental solution is to make a deep copy of the substituted terms.
It is now possible to declare syntactic macros at the global level.
macro ID = TERM;
After this definition, every occurrence of ID will be replaced by TERM.
For example, this can be used to avoid duplicating message definitions
among roles:
macro M1 = { nI, I}pk(R) ;
protocol X(I,R) {
role I {
send (I,R, M1);
}
role R {
recv (I,R, M1);
}
}
Introduced a new event:
match(pattern,groundterm)
This event can only be executed if pattern can be matched to groundterm.
Variable substitutions are persistent with respect to later events in
the same role.
Currently implemented as syntactic sugar, essentially unfolded in role R to:
fresh x;
send ( R,R, { groundterm }x );
recv ( R,R, { pattern }x );
This work is not complete yet in the send that the output still contains
the unfolding. Ideally, the graph rendered detects this syntactic sugar
and renders a simplified event. This should be possible on the basis of
the label name prefix.
Conflicts:
src/compiler.c
src/parser.y
src/scanner.l
src/tac.h
