51 lines
819 B
Go
51 lines
819 B
Go
package node
|
|
|
|
type Nullable struct {
|
|
attributes map[string]interface{}
|
|
position *Position
|
|
expr Node
|
|
}
|
|
|
|
func NewNullable(Expression Node) Node {
|
|
return &Nullable{
|
|
map[string]interface{}{},
|
|
nil,
|
|
Expression,
|
|
}
|
|
}
|
|
|
|
func (n Nullable) Attributes() map[string]interface{} {
|
|
return n.attributes
|
|
}
|
|
|
|
func (n Nullable) Attribute(Key string) interface{} {
|
|
return n.attributes[Key]
|
|
}
|
|
|
|
func (n Nullable) SetAttribute(Key string, Value interface{}) Node {
|
|
n.attributes[Key] = Value
|
|
return n
|
|
}
|
|
|
|
func (n Nullable) Position() *Position {
|
|
return n.position
|
|
}
|
|
|
|
func (n Nullable) SetPosition(p *Position) Node {
|
|
n.position = p
|
|
return n
|
|
}
|
|
|
|
func (n Nullable) Walk(v Visitor) {
|
|
if v.EnterNode(n) == false {
|
|
return
|
|
}
|
|
|
|
if n.expr != nil {
|
|
vv := v.GetChildrenVisitor("expr")
|
|
n.expr.Walk(vv)
|
|
}
|
|
|
|
v.LeaveNode(n)
|
|
}
|