Don't use data to drive behaviour, use behaviour.

[brackendawson]

This might be more of a functional proverb than a Go proverb, but I frequently see variables which exist only to switch a branch.

This leads to a clear implementation but an unclear (to the reader) call.

func Modify(s string, upper, quote bool) string {
	if upper {
		s = strings.ToUpper(s)
	}
	if quote {
		s = `"` + s + `"`
	}
	return s
}


Modify("this", true, true)

When passing behaviour the intent of the call is obvious.

func Modify(s string, mod ...func(string) string) string {
	for _, f := range mod {
		s = f(s)
	}
	return s
}

func Quote(s string) string {
	return `"` + s + `"`
}


Modify("this", Quote, strings.ToUpper)