scope_indentation.go

package main

import (
	"fmt"
	"strings"
)

// Global scope level
var scope = new(ScopeLevel)

func main() {
	for _, op := range []string{
		// program
		"open",
		"open",
		"read",
		"open",
		"write",
		"close",
		"close",
		"open",
		"read",
		"open",
		"read",
		"open",
		"read",
		"close",
		"close",
		"close",
		"write",
		"close",
	} {
		// Format based on scope
		Print(op)
	}
}

// Ops to Scope command map
var rules = map[string]func(string){
	"open":  scope.enter,
	"close": scope.exit,
}

// Print is a helper function to format ops
func Print(op string) {

	if sc, ok := rules[op]; ok {
		sc(op)
		return
	}

	scope.print(op)
}

// ScopeLevel type
type ScopeLevel int

func (s *ScopeLevel) enter(op string) {
	s.print(op)
	*s++
}

func (s *ScopeLevel) exit(op string) {
	if *s > 0 {
		*s--
	}
	s.print(op)
}

func (s *ScopeLevel) print(op string) {
	leftPad := ""

	if *s > 0 {
		leftPad = strings.Repeat("\t", int(*s))
	}

	fmt.Println(leftPad + op + "()")
}

Live code - https://play.golang.org/p/8Kwy_7Lqna

Output:

open()
    open()
        read()
        open()
            write()
        close()
    close()
    open()
        read()
        open()
            read()
            open()
                read()
            close()
        close()
    close()
    write()
close()