1	# src/rchars: a buffer of chars read one at a time and consed on the front
2	# (the last read first) as the String it spells, in one pass: each char goes
3	# onto the String built so far, with no reversed list in between (the shape
4	# `fromrev`, U016, reports). Pure.
5	import Base
6	
7	# the buffer's chars, first read first, then acc
8	def onto(buf: List<&2, Char>, acc: String) -> String:
9	  match buf:
10	    case Nil{}:
11	      acc
12	    case Con{h, t}:
13	      onto(t, SCon{h, acc})
14	
15	# the buffer's chars, first read first
16	def text(buf: List<&2, Char>) -> String:
17	  onto(buf, SNil{})