为什么filepath.Walk示例有不包括windows和plan9的生成标记？

Question

在https://pkg.go.dev/path/filepath#Walk

代码示例是

// +build !windows,!plan9

package main

import (
    "fmt"
    "io/fs"
    "os"
    "path/filepath"
)

func prepareTestDirTree(tree string) (string, error) {
    tmpDir, err := os.MkdirTemp("", "")
    if err != nil {
        return "", fmt.Errorf("error creating temp directory: %v\n", err)
    }

    err = os.MkdirAll(filepath.Join(tmpDir, tree), 0755)
    if err != nil {
        os.RemoveAll(tmpDir)
        return "", err
    }

    return tmpDir, nil
}

func main() {
    tmpDir, err := prepareTestDirTree("dir/to/walk/skip")
    if err != nil {
        fmt.Printf("unable to create test dir tree: %v\n", err)
        return
    }
    defer os.RemoveAll(tmpDir)
    os.Chdir(tmpDir)

    subDirToSkip := "skip"

    fmt.Println("On Unix:")
    err = filepath.Walk(".", func(path string, info fs.FileInfo, err error) error {
        if err != nil {
            fmt.Printf("prevent panic by handling failure accessing a path %q: %v\n", path, err)
            return err
        }
        if info.IsDir() && info.Name() == subDirToSkip {
            fmt.Printf("skipping a dir without errors: %+v \n", info.Name())
            return filepath.SkipDir
        }
        fmt.Printf("visited file or dir: %q\n", path)
        return nil
    })
    if err != nil {
        fmt.Printf("error walking the path %q: %v\n", tmpDir, err)
        return
    }
}

为什么go作者不包括windows和plan9？

Answer 1

不知何故，此更改是与提交消息一起添加的。

make Walk example runnable in the playground

• https://github.com/golang/go/commit/940811922fb528fabda91a2b2dbb401a06aeb1b3
• more在https://go-review.googlesource.com/c/go/+/122237/

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