1	import Base
2	
3	# Neutral datatypes shared by src/bitset.bend and spec/bitset.bend.
4	
5	type Error is Data:
6	  IndexOutOfRange{}
7	  LengthMismatch{}
8	
9	# Binary operations carry the operand as its logical bit sequence (bit 0
10	# first); the runner builds the operand bitset with the public from_bools.
11	type Op is Data:
12	  Length{}
13	  Get{index: Nat}
14	  Set{index: Nat}
15	  Clear{index: Nat}
16	  Count{}
17	  Union{other: List<&2, Bool>}
18	  Intersection{other: List<&2, Bool>}
19	  Difference{other: List<&2, Bool>}
20	  Xor{other: List<&2, Bool>}
21	  ToList{}
22	
23	type Obs is Data:
24	  ONat{value: Nat}
25	  OBit{result: Result<&2, &2, Error, Bool>}
26	  OUnit{result: Result<&2, &2, Error, Unit>}
27	  OList{members: List<&2, Nat>}