1	import Base
2	import ./state.bend as S
3	import ./packed.bend as P
4	
5	# Exactly eight big-endian U32 words (32 bytes), with no list allocation.
6	def digest(s: S.State) -> Array<U32>:
7	  match s:
8	    case S.H{a,b,c,d,e,f,g,h}:
9	      ANode{ANode{ANode{ALeaf{a},ALeaf{b}},ANode{ALeaf{c},ALeaf{d}}},ANode{ANode{ALeaf{e},ALeaf{f}},ANode{ALeaf{g},ALeaf{h}}}}
10	
11	def result(r: Maybe<&2,S.State>) -> Maybe<&1,Array<U32>>:
12	  match r:
13	    case None{}: None{}
14	    case Some{s}: Some{digest(s)}
15	
16	def sha256(input: Array<U32>, length: Nat) -> Maybe<&1,Array<U32>>:
17	  result(P.hash(input,length))