init init_acallexpr (
		n_expr: nullable AExpr,
		n_qid: nullable AQid,
		n_args: nullable AExprs
	)
	do
		_n_expr = n_expr.as(not null)
		n_expr.parent = self
		_n_qid = n_qid.as(not null)
		n_qid.parent = self
		_n_args = n_args.as(not null)
		n_args.parent = self
	end