must

A convenient library to do a must pattern

Problems

Before Go 1.18, if you want to panic when the regular expression cannot compile, you need to do it like this:

package main

import "regexp"

var re = must(regexp.Compile("
   
    "
   ))

func must(re *regexp.Regexp, err error) {
	// handle an error and if panic when error is not nil.
}

Ok. The Go standard library provides a convenient way to do this style by provides regexp.MustCompile for us. They do the same thing for package like template also. But why do we needs to write this kind of pattern for each type?

Go 1.18 save our life

Now Go 1.18 lands with generic feature. Now we can change it to this!:

package main

import (
	"regexp"

	"github.com/wingyplus/must"
)

var re = must.Must(regexp.Compile("
   
    "
   )) // The `Must` is generic!
var tmpl = must.Must(template.New("name").Parse("text")) // Yeah, use the same logic.