go - 如何使用库对象？

Question

我有一个错误。 Document 是 goquery 库中的结构对象。 我不能在下面的代码中使用它。我该怎么办？

package main
import (
    "log"
    "github.com/PuerkitoBio/goquery"
    "os"
)

func getLocalFile(filename string) (*Document) { // Error
    f, e := os.Open(FILTER_FILE)
    if e != nil {
        log.Fatal(e)
    }
    defer f.Close()

    doc, e := goquery.NewDocumentFromReader(f)
    if e != nil {
        log.Fatal(e)
    }
    return doc
}

const FILE_NAME = "input.html"
func main() {
    doc := getLocalFile(FILE_NAME)
    println(doc)
}

Answer 1

The Go Programming Language Specification

Qualified identifiers

A qualified identifier is an identifier qualified with a package name prefix. Both the package name and the identifier must not be blank.

QualifiedIdent = PackageName "." identifier .

A qualified identifier accesses an identifier in a different package, which must be imported. The identifier must be exported and declared in the package block of that package.

math.Sin  // denotes the Sin function in package math

使用完全限定名称:goquery.Document。例如，

package main

import (
    "github.com/PuerkitoBio/goquery"
    "log"
    "os"
)

func getLocalFile(filename string) *goquery.Document {
    f, e := os.Open(filename)
    if e != nil {
        log.Fatal(e)
    }
    defer f.Close()

    doc, e := goquery.NewDocumentFromReader(f)
    if e != nil {
        log.Fatal(e)
    }
    return doc
}

const FILE_NAME = "input.html"

func main() {
    doc := getLocalFile(FILE_NAME)
    println(doc)
}