Golang - 通过接口获取指向结构字段的指针

Question

我正处于了解Go中接口的早期阶段.我正在写一些逻辑模拟,并有类似下面的代码(我在这里大大简化):

请参阅我的问题的评论:

type LogicNode struct {
    Input   *bool
    Output   *bool
    Operator string
    Next     Node
}

func (n *LogicNode) Run() {
    // do some stuff here
    n.Next.Run()
}

type Node interface {
    Run()
}

func main() {

    nodes := make([]Node, 1000)

    for i := 0; i < 1000; i++ {
        n := LogicNode{
            //assign values etc.
        }
        nodes[i] = &n
    }

    for i, node := range nodes {
        // I need to access LogicNode's Output pointer here, as a *bool.
        // so I can set the same address to other Node's Input thereby "connecting" them.
        // but I could only get something like this:

        x := reflect.ValueOf(node).Elem().FieldByName("Output")

        // which is <*bool Value>
        // I couldn't find a way to set a new *bool to the underlying (LogicNode) Struct's Input or Output..
    }
}

我使用接口的原因是因为有其他节点类型FloatNode MathNode等具有不同的字段,但它们实现了自己的run方法.

我已成功使用Value的SetString或SetBool方法,但无法在那里设置指针...提前感谢.

Answer 1

您可以使用Set generic version更新字段值:

package main

import (
    "fmt"
    "reflect"
)

type LogicNode struct {
    Input   *bool
    Output   *bool
    Operator string
    Next     Node
}

func (n *LogicNode) Run() {
    // do some stuff here
    // n.Next.Run()
    fmt.Printf("LogicNode.Input = %v (%v)\n", *n.Input, n.Input)
}

type Node interface {
    Run()
}

func main() {
    input := false
    input2 := true
    fmt.Printf("Input1 = %v (%v)\n", input, &input)
    fmt.Printf("Input2 = %v (%v)\n", input2, &input2)
    var node Node = &LogicNode{Input: &input} // Remember, interfaces are pointers
    node.Run()
    x := reflect.ValueOf(node).Elem().FieldByName("Input")
    x.Set(reflect.ValueOf(&input2))
    node.Run()
}

输出:

Input1 = false (0x10500168)
Input2 = true (0x10500170)
LogicNode.Input = false (0x10500168)
LogicNode.Input = true (0x10500170)

这里的游乐场.