前言

github.com/google/cel-go/common/types/ref

type Val interface {// ConvertToNative converts the Value to a native Go struct according to the// reflected type description, or error if the conversion is not feasible.ConvertToNative(typeDesc reflect.Type) (interface{}, error)// ConvertToType supports type conversions between value types supported by// the expression language.ConvertToType(typeValue Type) Val// Equal returns true if the `other` value has the same type and content as// the implementing struct.Equal(other Val) Val// Type returns the TypeValue of the value.Type() Type// Value returns the raw value of the instance which may not be directly// compatible with the expression language types.Value() interface{}
}

当我们实现了一个interface时，使用swtich case去判断，会命中哪条结果？

switch i := v.(type) {case ref.Val:return resolveType(i.Value())case *CustomType:return resolveType(i.Value())default:}

经过测试发现，谁的case靠前，会命中谁，哪怕CustomType有一些私有方法
后面空了看看switch 底层实现。。