1	# Order: comparators for OMap, List.sort, and other templates that take ~cmp.
2	import Base
3	
4	def string.fin(c: Cmp, rest: Cmp) -> Cmp:
5	  match c:
6	    case LT{}:
7	      LT{}
8	    case EQ{}:
9	      rest
10	    case GT{}:
11	      GT{}
12	
13	# Strings in code-point order, a prefix before its extensions. String.order gives
14	# the same answers, but it rebuilds both strings on every call.
15	def string(a: String, b: String) -> Cmp:
16	  match a b:
17	    case SNil{} SNil{}:
18	      EQ{}
19	    case SNil{} SCon{h, t}:
20	      LT{}
21	    case SCon{h, t} SNil{}:
22	      GT{}
23	    case SCon{Chr{+x}, s} SCon{Chr{+y}, t}:
24	      string.fin(U32.cmp(x, y), string(s, t))