Abusing funcMap and text/template

non-shitty-http.go

package main

import (
	"errors"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"text/template"
)

func goGet(url string, out chan interface{}) interface{} {
	// out := make(chan string)

	go func() {
		out <- get(url)
	}()

	return <-out
}

func get(urlStr string) string {
	r, err := http.Get(urlStr)
	if err != nil {
		log.Fatal(err)
	}

	body, err2 := ioutil.ReadAll(r.Body)
	r.Body.Close()

	if err2 != nil {
		log.Fatal(err)
	}

	return string(body)
}

type storage struct {
	data interface{}
}

func keywordMake() string {
	return "make"
}

func keywordChan(arg string) (*string, error) {
	out := "makechan"
	if arg == "make" {
		return &out, nil
	}

	return nil, errors.New("invalid keyword")
}

func keywordString(arg string) (chan interface{}, error) {
	if arg == "makechan" {
		return make(chan interface{}), nil
	}

	return nil, errors.New("invalid keyword")
}

func betterHttp(str string) {
	// First we create a FuncMap with which to register the function.
	funcMap := template.FuncMap{
		"get":    goGet,
		"make":   keywordMake,
		"chan":   keywordChan,
		"string": keywordString,
	}

	// Create a template, add the function map, and parse the text.
	tmpl, err := template.New("blah").Funcs(funcMap).Parse(str)
	if err != nil {
		log.Fatalf("parsing: %s", err)
	}

	// Run the template to verify the output.
	err = tmpl.Funcs(funcMap).Execute(os.Stdout, storage{})
	if err != nil {
		log.Fatalf("execution: %s", err)
	}
}

func main() {
	str := `{{get "https://api.github.com/users/phated/repos?per_page=1" (make | chan | string)}}`

	betterHttp(str)
}