go | 易学教程

How to determine the method set of an interface in Golang?

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问题 How would one print the method set of the following interface? type Searcher interface { Search(query string) (found bool, err error) ListSearches() []string ClearSearches() (err error) } Such that Search ListSearches ClearSearches is printed out? (Without knowledge of a concrete type which implements it). 回答1: reflect package is the right tool for this.Using reflection one can get the type information of a variable without knowing the type before hand . Here is a code snippet showing how to

vue之vue-router嵌套路由

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1、定义路由 routes: [ { path: ' /product ' , //第一层路由 name: ' product ' , component: Vproductcontent, //父组件渲染的是子组件的内容<routerview/> 写在父组件中 children:[ { path: ' /product/hotproduct ' , //第二层路由 name: ' hotproduct ' , component: Vhotproduct, children:[ { path: ' /product/hotproduct/detail/:id(\\d+) ' , //第三层路由 component: Vhotproductdetail, } ] }, ] }, ] 2、使用 router-link 组件来导航在左侧菜单栏的Vleft组件中使用router-link <ul class = " nav nav-sidebar " > <router-link tag= " li " to= " /product " ><a href= " # " >产品管理</a></router-link> </ul> 2.1 加入默认样式默认选中的样式是在li标签上加上class="active" # 将其渲染成以下样式，这是默认选中的样式 <ul class = "

Istio 1.1尝鲜记

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近几天Istio1.1的发布引起了技术界巨大的反响，为了让更多技术爱好者能够亲自体验Istio1.1，公司的技术大佬赶出了这篇尝鲜教程，其中包括环境、安装、可能遇到的问题及解决方式等，希望对大家有所帮助。环境已经安装了 Kubernetes 集群，有1个 master 和4个 node。操作系统都是 CentOS Linux 7。下载 Istio 安装文件 curl -L https: // git.io/getLatestIstio | ISTIO_VERSION=1.1.0 sh - export PATH = " $PATH:/root/istio-1.1.0/bin " 安装 Tiller 这里选择在 Helm 和 Tiller 的环境中使用 helm install 命令进行安装的方式。 kubectl apply -f install/kubernetes/helm/helm-service-account.yaml 　假如已经安装过，结果如下： helm init --service-account tiller 安装 istio-init chart 更新 Helm 的本地包缓存： helm repo add istio.io "https://gcsweb.istio.io/gcs/istio-prerelease/daily-build/release-1

Go json Unmarshaller is not called

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问题 I'm fairly new to Golang. And I was looking for a way to do some custom stuff for marshaling and unmarshalling json . I have found the solution to implement Marshaller and Unmarshaller interfaces. Here is my struct with implemented interfaces (I have also implemented Stringer): type Data struct { Foo string `json:"foo"` bar string } func (d Data) MarshalJSON() ([]byte, error) { return []byte("{\"foo\":\"test\",\"bar\":\"data\"}"), nil } func (d Data) String() string { return fmt.Sprintf("Foo:

Executing command with spaces in one of the parts

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问题 I am running a command through the os/exec package that is called like this: out, err := Exec("ffprobe -i '/media/Name of File.mp3' -show_entries format=duration -v quiet -of csv=p=0", true, true) The function I have written to execute command line calls is: func Exec(command string, showOutput bool, returnOutput bool) (string, error) { log.Println("Running command: " + command) lastQuote := rune(0) f := func(c rune) bool { switch { case c == lastQuote: lastQuote = rune(0) return false case

go实现dgraph的各种操作

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go实现dgraph的各种操作 import "github.com/dgraph-io/dgo" import "github.com/dgraph-io/dgo/protos/api" import "google.golang.org/grpc" 我在这篇博客将会做以下的工作: 初始化Node 添加Node 查询数据库为数据库添加Edge , 即添加predicate<朋友> 更新数据库删除Node 之前我已经实现了用dgraph的http客户端实现 dgraph 的各种操作, 但是在 go 客户端实现和 http 客户端实现还是存在着比较大的区别. 因此, 我就写了这篇博客用于记录. 哦, 对了, 另外还有一个关键就是, 在我写这篇博客的时候 dgraph 在GODOC和GOWalker的文档都还没补全, 有很多方法都还只是写了个名, 甚至都没介绍, 对新手非常不友好. 初始化数据库此处, 我将创建五个用户作为基础数据库初始化Person的结构体, 表的属性从中也可以看出 type Person struct{ Uid string `json:"uid,omitempty"` Name string `json:"name,omitempty"` From string `json:"from,omitempty"` NameOFcn string `json:

how to make golang execute a string

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问题 I am not asking to make golang do some sort of "eval" in the current context, just need it to take a input string (say, received from network) and execute it as a separate golang program. In theory, when you run go run testme.go , it will read the content of testme.go into a string and parse, compile and execute it. Wonder if it is possible to call a go function to execute a string directly. Note that I have a requirement not to write the string into a file. UPDATE1 I really want to find out

how to make golang execute a string

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go get -> cannot download, /home/azhukov/go is a GOROOT, not a GOPATH

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问题 Good day! I am trying to install gb (vendoring tool for go) in Google Cloud. I try go get and it fails: azhukov@gce-machine:~$ go get -v github.com/constabulary/gb/... package github.com/pkg/errors: cannot download, /home/azhukov/go is a GOROOT, not a GOPATH. For more details see: 'go help gopath' here is env: azhukov@gce-machine:~$ echo $GOPATH, $GOROOT, $PATH /home/azhukov/go, , /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/usr/local/go/bin:/home/azhukov/go/bin go version:

转,sql 50道练习题

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SQL语句50题 -- 一、创建教学系统的数据库，表，以及数据 --student(sno,sname,sage,ssex) 学生表 --course(cno,cname,tno) 课程表 --sc(sno,cno,score) 成绩表 --teacher(tno,tname) 教师表 --1.创建数据库test1 use master GO IF EXISTS (SELECT name FROM master.dbo.sysdatabases WHERE name = 'test1') DROP DATABASE test1 GO CREATE DATABASE test1 GO use test1 GO --2.创建教师表 CREATE TABLE [dbo].[teacher]( [tno] [int] NOT NULL PRIMARY KEY, [tname] [nvarchar](20) NOT NULL ) --插入数据 INSERT INTO teacher(tno,tname)VALUES(1,'张老师') INSERT INTO teacher(tno,tname)VALUES(2,'王老师') INSERT INTO teacher(tno,tname)VALUES(3,'李老师') INSERT INTO teacher(tno,tname)VALUES(4,