1	import Base
2	
3	# Returns the count-limit decision for a mutation batch.
4	type Validation is Data:
5	  ValidBatch{}
6	  EmptyBatch{}
7	  BatchCountExceeded{}
8	
9	# Returns the maximum number of mutations in a batch.
10	def max_batch_count() -> Nat:
11	  256n
12	
13	# Checks whether a batch count is within the allowed range.
14	def within_batch_count(count: Nat) -> Bool:
15	  Nat.is_le(count, max_batch_count())
16	
17	# Rejects empty and oversized batches before writing.
18	def validate_count(count: Nat) -> Validation:
19	  match count:
20	    case 0n:
21	      EmptyBatch{}
22	    case count:
23	      Bool.pick(Validation, within_batch_count(count), ValidBatch{}, BatchCountExceeded{})