1	import Base
2	# Built-in transparent payloads need no caller-authored display adapter.
3	def u32(value:U32) -> U32 & String:
4	  +value=value
5	  (value,U32.show(value))
6	def bool(value:Bool) -> Bool & String:
7	  +value=value
8	  (value,Bool.show(value))
9	def leaf(result:U32 & String) -> Array<U32> & String:
10	  match result:
11	    case (value,text):(ALeaf{value},"leaf:" ++ text)
12	def node(left:Array<U32> & String,right:Array<U32> & String) -> Array<U32> & String:
13	  (left,a)=left
14	  (right,b)=right
15	  (ANode{left,right},"node(" ++ a ++ "," ++ b ++ ")")
16	def array(value:Array<U32>) -> Array<U32> & String:
17	  match value:
18	    case ALeaf{value}:leaf(u32(value))
19	    case ANode{left,right}:node(array(left),array(right))