calc

type Calc interface {
	Eval() interface{}
}

type Context interface {
	Var(name string) func() interface{}
	Call(name string) func(args ...interface{}) interface{}

	Add(a, b interface{}) interface{}
	Sub(a, b interface{}) interface{}
	Mul(a, b interface{}) interface{}
	Div(a, b interface{}) interface{}
	Rem(a, b interface{}) interface{}
	Equal(a, b interface{}) interface{}
	NotEqual(a, b interface{}) interface{}
	Less(a, b interface{}) interface{}
	Greater(a, b interface{}) interface{}
	LessEqual(a, b interface{}) interface{}
	GreaterEqual(a, b interface{}) interface{}
	LogicalOr(a, b interface{}) interface{}
	LogicalAnd(a, b interface{}) interface{}
	BitOr(a, b interface{}) interface{}
	BitAnd(a, b interface{}) interface{}
	BitXor(a, b interface{}) interface{}

	Sub1(a interface{}) interface{}
	Not(a interface{}) interface{}
}