1	import Base
2	
3	# The output formats as small numbers, for records that cannot name the Fmt
4	# type (the `auto` flags): 0 text, 1 json, 2 csv, 3 yaml, 4 toon. out.bend
5	# turns a code into a Fmt.
6	
7	# The code of a `--format` argument, none for an unknown name.
8	def of_name(+s: String) -> Maybe<&2, U32>:
9	  Bool.pick(Maybe<&2, U32>, String.eq(s, "text"), Some{0},
10	  Bool.pick(Maybe<&2, U32>, String.eq(s, "json"), Some{1},
11	  Bool.pick(Maybe<&2, U32>, String.eq(s, "csv"), Some{2},
12	  Bool.pick(Maybe<&2, U32>, String.eq(s, "yaml") || String.eq(s, "yml"), Some{3},
13	  Bool.pick(Maybe<&2, U32>, String.eq(s, "toon"), Some{4}, None{})))))
14	
15	def choices() -> String:
16	  "'text', 'json', 'csv', 'yaml', 'toon'"
17	
18	def invalid(+flag: String, +v: String) -> String:
19	  "argument " ++ flag ++ ": invalid choice: '" ++ v ++ "' (choose from " ++ choices() ++ ")"