1	# shake/args: the process's arguments, each word reusable, internal (main.bend
2	# exports it). `IO.args` answers a `&1` list that starts with the program as
3	# invoked (bend 2.0.32 and later); the rest of a program reads the line more
4	# than once, so `words` drops that head and copies the rest.
5	import Base
6	
7	# a &1 list copied to &2
8	def copy(xs: List<&1, String>) -> List<&2, String>:
9	  match xs:
10	    case Nil{}:
11	      Nil{}
12	    case Con{+h, t}:
13	      h <> copy(t)
14	
15	# the arguments of an IO.args line: every word after the program name, copied
16	def words(xs: List<&1, String>) -> List<&2, String>:
17	  match xs:
18	    case Nil{}:
19	      Nil{}
20	    case Con{_h, t}:
21	      copy(t)
22	
23	# the process's arguments, without the program name
24	def argv() -> IO(List<&2, String>):  # noqa: L001 IO: reads argv (SHAKE-TRUST-4)
25	  IO.bind(List<&1, String>, List<&2, String>, IO.args(),
26	    xs => IO.pure(List<&2, String>, words(xs)))