public BinaryDerivation /*@Nullable*/[] instantiate(VarInfo var1, VarInfo var2) {
boolean enabled = SequencesPredicate.dkconfig_enabled;
if (!enabled) return null;
if (debug.isLoggable(Level.FINE)) {
debug.fine("Trying to instantiate " + var1.name() + " and " + var2.name());
}
if (!(var1.rep_type.isArray()) || !(var2.rep_type.isArray())) {
return null;
}
if (!var1.aux.getFlag(VarInfoAux.HAS_ORDER) || !var2.aux.getFlag(VarInfoAux.HAS_ORDER)) {
// Order doesn't matter, then predication is meaningless
return null;
}
if (SequencesPredicate.dkconfig_boolOnly) {
if (!(var2.file_rep_type == ProglangType.BOOLEAN_ARRAY)) {
return null;
}
}
if (var1.derived != null || var2.derived != null) {
// From derived variables. Don't derive.
return null;
}
if (SequencesPredicate.dkconfig_fieldOnly) {
if (!var1.is_field() || !var2.is_field()) return null;
if (!var1.has_same_parent(var2)) return null;
} else {
// There may be predications that aren't of the x.a and x.b type
}
// Now we finally can derive
if (debug.isLoggable(Level.FINE)) {
debug.fine(
var1.ppt + ": " + var1.name() + " and " + var2.name() + " are worth deriving from");
}
return new BinaryDerivation[] {
new SequencesPredicate(var1, var2, 0, "false"), new SequencesPredicate(var1, var2, 1, "true"),
// new SequencesPredicate (var1, var2, 0, "nonNull", false),
};
}
