1	import Base
2	
3	# The global options taken off a command line before the verb sees it:
4	# `--format NAME` (or `--format=NAME`), `--no-input` (never read standard
5	# input: a prompt becomes an error) and `--yes` (answer a confirmation).
6	# `config import` and `profile import` keep `--format`: there it names the
7	# format of the input file.
8	
9	type G is Data:
10	  G{rest: List<&2, String>, fmt: Maybe<&2, String>, noin: Bool, yes: Bool, err: String, pending: Bool}
11	
12	def start() -> G:
13	  G{[], None{}, False{}, False{}, "", False{}}
14	
15	def with_fmt(+g: G, +v: String) -> G:
16	  match g:
17	    case G{rest, fmt, noin, yes, err, p}:
18	      G{rest, Some{v}, noin, yes, err, False{}}
19	
20	def pend(+g: G) -> G:
21	  match g:
22	    case G{rest, fmt, noin, yes, err, p}:
23	      G{rest, fmt, noin, yes, err, True{}}
24	
25	def with_noin(+g: G) -> G:
26	  match g:
27	    case G{rest, fmt, noin, yes, err, p}:
28	      G{rest, fmt, True{}, yes, err, p}
29	
30	def with_yes(+g: G) -> G:
31	  match g:
32	    case G{rest, fmt, noin, yes, err, p}:
33	      G{rest, fmt, noin, True{}, err, p}
34	
35	def keep(+h: String, +g: G) -> G:
36	  match g:
37	    case G{rest, fmt, noin, yes, err, p}:
38	      G{h <> rest, fmt, noin, yes, err, p}
39	
40	def is_pending(+g: G) -> Bool:
41	  match g:
42	    case G{rest, fmt, noin, yes, err, p}:
43	      p
44	
45	def sel.g(c: Bool, +a: G, +b: G) -> G:
46	  match c:
47	    case True{}:
48	      a
49	    case False{}:
50	      b
51	
52	def free(+keep_fmt: Bool, +h: String, +g: G) -> G:
53	  sel.g(Bool.not(keep_fmt) && String.eq(h, "--format"), pend(g),
54	  sel.g(Bool.not(keep_fmt) && String.starts_with(h, "--format="), with_fmt(g, String.drop(h, 9n)),
55	  sel.g(String.eq(h, "--no-input"), with_noin(g),
56	  sel.g(String.eq(h, "--yes"), with_yes(g),
57	  keep(h, g)))))
58	
59	def step(+keep_fmt: Bool, +h: String, +g: G) -> G:
60	  sel.g(is_pending(g), with_fmt(g, h), free(keep_fmt, h, g))
61	
62	def go(+keep_fmt: Bool, args: List<&2, String>, +g: G) -> G:
63	  match args:
64	    case Nil{}:
65	      g
66	    case Con{h, t}:
67	      go(keep_fmt, t, step(keep_fmt, h, g))
68	
69	def end2(+g: G) -> G:
70	  match g:
71	    case G{rest, fmt, noin, yes, err, p}:
72	      G{List.reverse(&2, String, rest), fmt, noin, yes, Bool.pick(String, p, "argument --format: expected one argument", err), False{}}
73	
74	# The words left, the format name given, and the two switches. `keep_fmt`:
75	# leave `--format` where it is.
76	def split(+keep_fmt: Bool, args: List<&2, String>) -> G:
77	  end2(go(keep_fmt, args, start()))