An ast grammar for our "abc example" (term node)
grammar ABC::ASTGrammar is TGE::Grammar;
transform past (ABC::Grammar::term) :language('PIR') {
## build a PAST::Val node for this term
## get the constant value
$S0 = node.'text'()
.local pmc termpast
termpast = new 'PAST::Val'
termpast.'init'('node'=>node, 'name'=>$S0, 'vtype'=>'.Integer')
.return (termpast)
}
node is automatically set by a TGE preamble