op-geth/ethutil/list.go

47 lines
1.1 KiB
Go

package ethutil
import "reflect"
// The list type is an anonymous slice handler which can be used
// for containing any slice type to use in an environment which
// does not support slice types (e.g., JavaScript, QML)
type List struct {
list reflect.Value
Length int
}
// Initialise a new list. Panics if non-slice type is given.
func NewList(t interface{}) *List {
list := reflect.ValueOf(t)
if list.Kind() != reflect.Slice {
panic("list container initialized with a non-slice type")
}
return &List{list, list.Len()}
}
func EmptyList() *List {
return NewList([]interface{}{})
}
// Get N element from the embedded slice. Returns nil if OOB.
func (self *List) Get(i int) interface{} {
if self.list.Len() > i {
return self.list.Index(i).Interface()
}
return nil
}
// Appends value at the end of the slice. Panics when incompatible value
// is given.
func (self *List) Append(v interface{}) {
self.list = reflect.Append(self.list, reflect.ValueOf(v))
self.Length = self.list.Len()
}
// Returns the underlying slice as interface.
func (self *List) Interface() interface{} {
return self.list.Interface()
}