1	import Base
2	
3	# Pure checkpoint policy. An unset value is represented by the empty string;
4	# the non-empty guard distinguishes disabled injection from an exact match.
5	def nonempty(value: String) -> Bool:
6	  match value:
7	    case SNil{}: False{}
8	    case SCon{_, _}: True{}
9	
10	# Handle enabled in the crash injection policy.
11	def enabled(+configured: String, requested: String) -> Bool:
12	  Bool.and(nonempty(configured), String.eq(configured, requested))