This exists because Go won't parse flag arguments ("-o" or "--opt") that come after positional arguments:
f := flag.NewFlagSet("foo", flag.ExitOnError)
opt := f.String("opt", "", "an option")
f.Parse([]string{"regular-argument", "--opt", "theoption"})
fmt.Println(f.Args())
fmt.Println(*opt) // ""Sometimes this does the right thing - "go" takes different flags than "go build" for example and you don't want to parse "go" flags placed after "build". However sometimes you are at the end of the parse chain and anything that's left should be counted as an argument.
This does the dumbest possible thing which is to rearrange the flags so any
options come first. Anything after -- is ignored. A single - counts as a
positional (i.e. non-flag) argument.
f := flag.NewFlagSet("test", flag.ContinueOnError)
f.String("blah", "", "Blah")
f.Bool("baz", false, "Baz")
args := Rearrange(f, []string{"foo", "two", "--blah", "bar", "another", "--str=value", "--baz", "--", "--last", "option"})
fmt.Println(args)
// Output: [--blah bar --str=value --baz foo two another -- --last option]