Struct UnaryNode

expr/node.go:288–291

UnaryNode negates a single node argument ( not | ! ) !eq(5,6) !true !(true OR false) !toint(now())

	//    !(true OR false)
	//    !toint(now())
	UnaryNode struct {
		Arg      Node
		Operator lex.Token
	}

	// IncludeNode references a named node
	//