Where?

gistfile1.txt

The where() function returns the output:

~/tmp/where ❯ go run main.go
main.a in "/Users/[redacted]/tmp/where/main.go" returns from line 19

Maybe useful for debugging some large function when you don't have the patience for it.

where.go

package main

import (
	"fmt"
	"runtime"
)

func where() {
	pc, file, line, _ := runtime.Caller(1)
	fn := runtime.FuncForPC(pc)
	fmt.Printf("%s in %q returns from line %d\n", fn.Name(), file, line)
}

func a(i int) string {
	defer where()

	switch i {
	case 1:
		return "one"
	case 2:
		return "two"
	case 3:
		return "three"
	}
	return "?"
}

func main() {
	a(1)
}