Refactor cli arg parsing to not use vars defined in a clause head

Author: jwarwick

lib/ex_doc/cli.ex

@@ -7,15 +7,7 @@ defmodule ExDoc.CLI do
  opts = elem(parsed, 0)
  args = elem(parsed, 1)
 
- case args do
- [project, version, source_beam] -> :ok
- [_,_,_|_] ->
- IO.puts "Too many arguments.\n"
- print_usage()
- _ ->
- IO.puts "Too few arguments.\n"
- print_usage()
- end
+ [project, version, source_beam] = parse_args(args)
 
  if formatter = opts[:formatter] do
  opts = Keyword.put(opts, :formatter, String.split(formatter, "."))
@@ -25,6 +17,19 @@ defmodule ExDoc.CLI do
  ExDoc.generate_docs(project, version, opts)
  end
 
+ defp parse_args([_project, _version, _source_beam] = args), do: args
+ defp parse_args([_, _, _ | _]) do
+ IO.puts "Too many arguments.\n"
+ print_usage()
+ exit(1)
+ end
+ defp parse_args(_) do
+ IO.puts "Too few arguments.\n"
+ print_usage()
+ exit(1)
+ end
+
+
  defp print_usage do
  IO.puts %S"""
  Usage:
@@ -68,6 +73,5 @@ defmodule ExDoc.CLI do
  https://github.com/elixir-lang/dynamo/blob/v1.0/%{path}#L%{line}
 
  """
- exit(1)
  end
 end