1	# ezhttp/src/body: request entity as empty, UTF-8 text, or packed octets
2	# (bend-kit-bytes). Core does not depend on ezjson. Callers plug
3	# encode/decode through Bend type parameters (BYO JSON or any other
4	# representation).
5	import Base
6	import bend-kit-bytes@0.3.2.0/bytes.bend as Bytes
7	
8	# what rides in a request: nothing, text, or raw octets
9	type Body is Type:
10	  Empty{}
11	  Plain{text: String}
12	  Octets{bytes: Bytes.Bytes}
13	
14	# what the request text needs to know of a body: its text, or how many
15	# octets follow it (SPEC.md HTTP-CLI-10)
16	type Shape is Data:
17	  ShapeText{text: String}
18	  ShapeOctets{n: U32}
19	
20	# an octets body's count: its shape, and the octets handed back
21	def body.sized(r: Bytes.Bytes & U32) -> Shape & Bytes.Bytes:
22	  (b, +n) = r
23	  (ShapeOctets{n}, b)
24	
25	# a body as its shape and the octets sent after the request text: a text
26	# body's are none, and the empty body is the empty text
27	def body.shape(b: Body) -> Shape & Bytes.Bytes:
28	  match b:
29	    case Empty{}:
30	      (ShapeText{""}, Bytes.new(0))
31	    case Plain{text}:
32	      (ShapeText{text}, Bytes.new(0))
33	    case Octets{bytes}:
34	      body.sized(Bytes.length(bytes))
35	
36	# octets, one character each (each 0..255), from a list of their values
37	def octets.chars(bs: List<&2, U32>) -> String:
38	  match bs:
39	    case []:
40	      ""
41	    case h <> t:
42	      SCon{Char.from_u32(h), octets.chars(t)}
43	
44	# empty body
45	def body.empty() -> Body:
46	  Empty{}
47	
48	# UTF-8 text body
49	def body.text(s: String) -> Body:
50	  Plain{s}
51	
52	# octets body
53	def body.octets(bytes: Bytes.Bytes) -> Body:
54	  Octets{bytes}
55	
56	# an octets body from a list of octet values (each 0..255; a value past 255
57	# keeps its low 8 bits)
58	def body.list(bs: List<&2, U32>) -> Body:
59	  Octets{Bytes.from_string(octets.chars(bs))}
60	
61	# BYO encode: any value to a text body via the caller's encoder
62	def body.encode(~A: Data, ~to_text: A -> String, value: A) -> Body:
63	  Plain{to_text(value)}
64	
65	# BYO decode: body text to a value via the caller's decoder
66	def body.decode(~A: Data, ~from_text: String -> Maybe<&2, A>, s: String)
67	  -> Maybe<&2, A>:
68	  from_text(s)