1	import Base
2	import ./Protocol.bend as Protocol
3	
4	# Carries the state for ReadDisposition.
5	type ReadDisposition is Data:
6	  ReadInterrupted{}
7	  ReadWouldBlock{}
8	  ReadFailure{}
9	
10	# Carries the state for WriteDisposition.
11	type WriteDisposition is Data:
12	  WriteInterrupted{}
13	  WriteWouldBlock{}
14	  WriteFailure{}
15	
16	def read.disposition(code: U32) -> ReadDisposition:
17	  match code:
18	    case 4: ReadInterrupted{}
19	    case 11: ReadWouldBlock{}
20	    case 35: ReadWouldBlock{}
21	    case _: ReadFailure{}
22	
23	def write.disposition(code: U32) -> WriteDisposition:
24	  match code:
25	    case 4: WriteInterrupted{}
26	    case 11: WriteWouldBlock{}
27	    case 35: WriteWouldBlock{}
28	    case _: WriteFailure{}
29	def write_chunk.copied(copies: U32 & U32 & U32) -> U32:
30	  match copies:
31	    case (checked, (retained, _)):
32	      Bool.pick(U32, U32.is_le(checked, 65536), retained, 65536)
33	
34	# Caps one socket write request while preserving the remaining byte count.
35	def write_chunk(remaining: U32) -> U32:
36	  write_chunk.copied(Protocol.u32.duplicate.triple(remaining))