获取XML中的属性的值，但由Go中另一个属性的值确定什么元素

In the following example:

package main

import (
    "fmt"
    "encoding/xml"
)

var data = `
<data>
    <text id="0" action="wake"/>
    <text id="1" action="eat"/>
    <text id="2" action="bathe"/>
    <text id="3" action="walk"/>
</data>
`

type Result struct {
    XMLName xml.Name `xml:"data"`
    Action string //this is the part I want to solve
}


func main() {
    res := Result{}
    xml.Unmarshal(data, &res)
    fmt.Printf("%#v", res)
}

I want to get is the following struct:

{XMLName: xml.Name{Space:"", Local:"data"}, Action:"eat"}

So can I get the value of action attribute on the fourth text element only? In other words, I want to get the value of an attribute of any arbitrary elements, but that element is decided by another attribute within that element (id=3 in this case).

One thing to solve the issue is to embed another struct which holds each text element as slices, and iterate over that slice and if the id field is 3, then I get that inner struct's action field... but it's too daunting and ineffective to process.

Thanks.

Unmarshal unmarshals XML to a struct. It is not called XPath because you cannot do what you want with Unmarshal.

Either unmarshal into a larger struct and iterate until id==3 as you suggested. (Not sure why you say this is inefficient. And I doubt that you measured the cost of doing before claiming inefficiency).

Or: Parse the XML manually with xml.Decoder and processing the Tokens yourself.