“Dados de cálculo no modelo Go” Respostas de código

Dados de cálculo no modelo Go

package main

import (
	"net/http"
	"text/template"
)

func main() {

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {

		html := `
		 <h1> Total days: {{ len .days }}</h1>

		 {{ with $days := "Days list" }}
		  <h1> {{ $days }} </h1>
		 {{ end }}

		 <ul>
				{{ range $index, $day := .days }}
					<li> {{ inc $index }}. {{ $day }} </li>
				{{ end }}
		 </ul>

		  <h1> Calculate: {{ add 4 2 }} </h1>
		`
		data := map[string][]string{"days": []string{"senin", "selasa", "rabu"}}
		tmpFunc := template.FuncMap{
			"inc": func(i int) int {
				return i + 1
			},
			"add": func(i int, j int) int {
				return i + j
			},
		}
		parse, err := template.New("index.html").Funcs(tmpFunc).Parse(html)
		tmp := template.Must(parse, err)
		tmp.Execute(w, data)
	})

	http.ListenAndServe(":3000", nil)
}