Smalltalk拥有自己的新方法

Question

Object subclass: Node [     

    |value|

    new [
        Transcript show: 'Test'.
            value := 6.
    ]

    getValue [
        ^value.
    ]

    set:sth [
        value := sth.
    ]

]

|data|
data := Node new.
Transcript show: (data getValue) printString ; cr. "nil"
data set:5.
Transcript show: (data getValue) printString. "5"

问题是new永远不会调用方法,所以我不能设置值或调用initialize函数.此外之后:

object := Node new. "Not called"
object new. "Here is called"

该方法被调用.如何解决？

Answer 1

#new必须定义Node class工作:

Object subclass: Node [     

    |value|

    getValue [
        ^value.
    ]

    set: sth [
        value := sth.
    ]

]

Node class extend: [
    new [ | node |
        Transcript show: 'Test'.
        node := (super new).
        node set: 6.
        ^ node
    ]
]

请注意,在这种情况下value无法访问#new,因此必须调用setter