libs/HTTPClient.bend source
libs/HTTPClient.bend on the hub · documented module
import Baseimport ./JSON.bend as Jsonimport 0xcfc8be7b076f41f95c8e118383892d55/encoding.bend as Encodingimport 0x49814d83de8f70993a43e1002be29ecd/bytes.bend as Bytesimport 0x1f2d80f53f971b16c6de6a65cb1918ae/url.bend as Urlimport ./wire/wire.bend as Wireimport ./wire/dns.bend as Dns# HTTP/1.1 client and codec. Implements the supported RFC 9112 framing subset# and RFC 9110 request/response semantics; see README.md for the scope.type Header is Data: Header{name: String, value: List<&2, U32>}type Target is Data: Target{tls: Bool, host: String, port: U32, authority: String, resource: String}type Request is Data: Request{method: String, url: String, headers: List<&2, Header>, body: List<&2, U32>}type Response is Data: Response{status: U32, headers: List<&2, Header>, body: List<&2, U32>, trailers: List<&2, Header>}type Limits is Data: Limits{header_bytes: U32, header_count: U32, body_bytes: U32, trailer_bytes: U32, trailer_count: U32, interim_count: U32, chunk_line_bytes: U32, wire_bytes: U32}type Error is Data: InvalidUrl{} UnsupportedScheme{} UnsupportedHost{} InvalidMethod{} InvalidHeader{} ReservedHeader{} InvalidByte{} InvalidStatus{} InvalidVersion{} InvalidFraming{} UnsupportedTransferEncoding{} UnexpectedEof{} LimitExceeded{} UnsupportedUpgrade{} NoProgress{} InvalidJson{} UnsupportedContentEncoding{} InvalidUtf8{} Configuration{} Connection{} Tls{} Io{} Timeout{}type Decode is Data: NeedMore{} Parsed{response: Response, rest: List<&2, U32>} Rejected{error: Error}type Cut is Data: CutFound{before: String, after: String} CutMore{} CutBad{}type StatusLine is Data: StatusOk{status: U32} StatusBad{error: Error}type HeadScan is Data: HeadMore{} HeadBad{error: Error} HeadDone{status: U32, headers: List<&2, Header>, rest: String, size: Nat}type HeadStep is Data: HeadContinue{rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat} HeadStepMore{} HeadStepBad{error: Error} HeadStepDone{status: U32, headers: List<&2, Header>, rest: String, size: Nat}type Options is Data: Options{limits: Limits, connect_ms: U32, read_ms: U32, write_ms: U32, total_ms: U32, fuel: U32}type Work is Data: EncodeWork{request: Request} DecodeWork{method: String, limits: Limits, bytes: List<&2, U32>, eof: Bool}type Outcome is Data: Encoded{result: Result<&2, &2, Error, List<&2, U32>>} Decoded{result: Decode}type Batch is Data: Leaf{work: Work} Fork{left: Batch, right: Batch}type BatchResult is Data: LeafResult{outcome: Outcome} ForkResult{left: BatchResult, right: BatchResult}def append_bytes(xs: List<&2, U32>, ys: List<&2, U32>) -> List<&2, U32>: match xs: case Nil{}: ys case h <> t: h <> append_bytes(t, ys)def append_headers(xs: List<&2, Header>, ys: List<&2, Header>) -> List<&2, Header>: match xs: case Nil{}: ys case h <> t: h <> append_headers(t, ys)def utf8_char_bmp(+c: U32, bmp: Bool) -> List<&2, U32>: match bmp: case True{}: ((224 + U32.shrn(c, 12n) : U32)) <> ((128 + U32.and(U32.shrn(c, 6n), 63) : U32)) <> ((128 + U32.and(c, 63) : U32)) <> Nil{} case False{}: ((240 + U32.shrn(c, 18n) : U32)) <> ((128 + U32.and(U32.shrn(c, 12n), 63) : U32)) <> ((128 + U32.and(U32.shrn(c, 6n), 63) : U32)) <> ((128 + U32.and(c, 63) : U32)) <> Nil{}def utf8_char_short(+c: U32, short: Bool) -> List<&2, U32>: match short: case True{}: ((192 + U32.shrn(c, 6n) : U32)) <> ((128 + U32.and(c, 63) : U32)) <> Nil{} case False{}: utf8_char_bmp(c, U32.is_lt(c, 65536))def utf8_char_ascii(+c: U32, ascii: Bool) -> List<&2, U32>: match ascii: case True{}: [c] case False{}: utf8_char_short(c, U32.is_lt(c, 2048))def utf8_scalar(+c: U32, scalar: Bool) -> U32: match scalar: case True{}: c case False{}: 65533def utf8_char(+c: U32) -> List<&2, U32>: +scalar = utf8_scalar(c, U32.is_le(c, 1114111)) utf8_char_ascii(scalar, U32.is_lt(scalar, 128))def utf8(+text: String) -> List<&2, U32>: match text: case SNil{}: Nil{} case SCon{Chr{+c}, rest}: append_bytes(utf8_char(c), utf8(rest))def valid_byte(n: U32) -> Bool: U32.is_lt(n, 256)def valid_byte_tail(valid: Bool, rest: Bool) -> Bool: match valid rest: case True{} True{}: True{} case _ _: False{}def valid_bytes(bytes: List<&2, U32>) -> Bool: match bytes: case Nil{}: True{} case h <> t: valid_byte_tail(valid_byte(h), valid_bytes(t))def byte_lists_equal(left: List<&2, U32>, right: List<&2, U32>) -> Bool: match left right: case Nil{} Nil{}: True{} case h <> lt k <> rt: Bool.and(U32.is_eq(h, k), byte_lists_equal(lt, rt)) case _ _: False{}def lower(s: String) -> String: String.to_lower(s)def is_hex_digit(c: Char) -> Bool: match c: case '0': True{} case '1': True{} case '2': True{} case '3': True{} case '4': True{} case '5': True{} case '6': True{} case '7': True{} case '8': True{} case '9': True{} case 'a': True{} case 'b': True{} case 'c': True{} case 'd': True{} case 'e': True{} case 'f': True{} case 'A': True{} case 'B': True{} case 'C': True{} case 'D': True{} case 'E': True{} case 'F': True{} case _: False{}def valid_escape_digits_checked(hi: Bool, lo: Bool, tail_valid: Bool) -> Bool: match hi lo tail_valid: case True{} True{} True{}: True{} case _ _ _: False{}def valid_escape_digits(hi: Char, lo: Char, tail_valid: Bool) -> Bool: valid_escape_digits_checked(is_hex_digit(hi), is_hex_digit(lo), tail_valid)def valid_percent_escapes(url: String) -> Bool: match url: case SNil{}: True{} case SCon{'%', rest}: match rest: case SCon{hi, SCon{lo, tail}}: valid_escape_digits(hi, lo, valid_percent_escapes(tail)) case _: False{} case SCon{_, rest}: valid_percent_escapes(rest)def valid_url_char_class(control_or_space: Bool, delete: Bool) -> Bool: match control_or_space delete: case True{} _: False{} case _ True{}: False{} case _ _: True{}def valid_url_char(+n: U32) -> Bool: valid_url_char_class(U32.is_lt(n, 33), U32.is_eq(n, 127))def valid_url_chars(url: String) -> Bool: match url: case SNil{}: True{} case SCon{h, t}: Bool.and(valid_url_char(Char.to_u32(h)), valid_url_chars(t))def valid_host_char(+c: U32) -> Bool: Bool.or(Bool.and(U32.is_le(48, c), U32.is_le(c, 57)), Bool.or(Bool.and(U32.is_le(65, c), U32.is_le(c, 90)), Bool.or(Bool.and(U32.is_le(97, c), U32.is_le(c, 122)), Bool.or(U32.is_eq(c, 45), U32.is_eq(c, 46)))))def valid_host_tail(host: String) -> Bool: match host: case SNil{}: True{} case SCon{h, t}: Bool.and(valid_host_char(Char.to_u32(h)), valid_host_tail(t))def valid_host_name(host: String) -> Bool: match host: case SNil{}: False{} case SCon{h, t}: Bool.and(valid_host_char(Char.to_u32(h)), valid_host_tail(t))def url_authority(+text: String) -> String: match text: case SNil{}: SNil{} case SCon{'/', _}: SNil{} case SCon{'?', _}: SNil{} case SCon{'#', _}: SNil{} case SCon{h, t}: SCon{h, url_authority(t)}def url_empty_port_scheme(url: String, prefix_len: Nat, matches: Bool) -> Bool: match matches: case False{}: False{} case True{}: String.ends_with(url_authority(String.drop(url, prefix_len)), ":")def url_has_empty_port(+url: String) -> Bool: Bool.or(url_empty_port_scheme(url, 7n, String.starts_with(url, "http://")), url_empty_port_scheme(url, 8n, String.starts_with(url, "https://")))def valid_url_form(+url: String) -> Bool: Bool.and(valid_url_chars(url), valid_percent_escapes(url))def parse_url_error(url: String, has_scheme: Bool, http: Bool, https: Bool) -> Result<&2, &2, Error, Target>: match has_scheme http: case False{} _: Fail{InvalidUrl{}} case True{} True{}: Fail{InvalidUrl{}} case True{} False{}: match https: case True{}: Fail{InvalidUrl{}} case False{}: Fail{UnsupportedScheme{}}def parse_url_target_error(is_ipv6: Bool) -> Result<&2, &2, Error, Target>: match is_ipv6: case True{}: Fail{UnsupportedHost{}} case False{}: Fail{InvalidUrl{}}def parse_url_target(+absolute: Url.Abs, scheme: String, +host: String, port: U32, resource: String, valid: Bool) -> Result<&2, &2, Error, Target>: match valid: case False{}: parse_url_target_error(String.contains(host, ":")) case True{}: Done{Target{String.eq(scheme, "https"), host, port, Url.host_field(absolute), resource}}def parse_url_result(+url: String, parsed: Maybe<&2, Url.Abs>) -> Result<&2, &2, Error, Target>: match parsed: case None{}: parse_url_error(url, String.contains(url, "://"), String.starts_with(url, "http://"), String.starts_with(url, "https://")) case Some{+absolute}: Url.Abs{scheme, host, port, resource} = absolute parse_url_target(absolute, scheme, host, port, resource, Bool.and(Bool.not(String.contains(host, ":")), Bool.and(valid_host_name(host), Bool.and(U32.is_lt(0, port), Bool.and(valid_url_form(url), Bool.not(url_has_empty_port(url)))))))def parse_url(+url: String) -> Result<&2, &2, Error, Target>: parse_url_result(url, Url.absolute(url))def field_values(+name: String, headers: List<&2, Header>) -> List<&2, List<&2, U32>>: match headers: case Nil{}: Nil{} case Header{+field, value} <> rest: +tail = field_values(name, rest) Bool.pick(List<&2, List<&2, U32>>, String.eq(String.to_lower(field), String.to_lower(name)), value <> tail, tail)def valid_method(method: String) -> Bool: match method: case "GET": True{} case "HEAD": True{} case "POST": True{} case "PUT": True{} case "PATCH": True{} case "DELETE": True{} case "OPTIONS": True{} case _: False{}def method_has_length(method: String) -> Bool: match method: case "POST": True{} case "PUT": True{} case "PATCH": True{} case _: False{}def token_char(+n: U32) -> Bool: Bool.or(Bool.and(U32.is_le(48, n), U32.is_le(n, 57)), Bool.or(Bool.and(U32.is_le(65, n), U32.is_le(n, 90)), Bool.or(Bool.and(U32.is_le(97, n), U32.is_le(n, 122)), Bool.or(U32.is_eq(n, 33), Bool.or(U32.is_eq(n, 35), Bool.or(U32.is_eq(n, 36), Bool.or(U32.is_eq(n, 37), Bool.or(U32.is_eq(n, 38), Bool.or(U32.is_eq(n, 39), Bool.or(U32.is_eq(n, 42), Bool.or(U32.is_eq(n, 43), Bool.or(U32.is_eq(n, 45), Bool.or(U32.is_eq(n, 46), Bool.or(U32.is_eq(n, 94), Bool.or(U32.is_eq(n, 95), Bool.or(U32.is_eq(n, 96), Bool.or(U32.is_eq(n, 124), U32.is_eq(n, 126))))))))))))))))))def token_tail(chars: List<&2, Char>) -> Bool: match chars: case Nil{}: True{} case h <> t: Bool.and(token_char(Char.to_u32(h)), token_tail(t))def valid_header_name_chars(chars: List<&2, Char>) -> Bool: match chars: case Nil{}: False{} case h <> t: Bool.and(token_char(Char.to_u32(h)), token_tail(t))def valid_header_name(name: String) -> Bool: valid_header_name_chars(String.to_list(name))def header_byte_allowed(n: U32, tab: Bool, control: Bool, delete: Bool, octet: Bool) -> Bool: match tab control delete octet: case _ _ True{} _: False{} case _ _ _ False{}: False{} case True{} _ _ True{}: True{} case False{} True{} False{} True{}: False{} case False{} False{} False{} True{}: True{} case _ _ _ _: False{}def valid_header_value_byte(+n: U32) -> Bool: header_byte_allowed(n, U32.is_eq(n, 9), U32.is_lt(n, 32), U32.is_eq(n, 127), U32.is_lt(n, 256))def valid_header_value_bytes(bytes: List<&2, U32>) -> Bool: match bytes: case Nil{}: True{} case h <> t: Bool.and(valid_header_value_byte(h), valid_header_value_bytes(t))def reserved_header(+name: String) -> Bool: +lowered = String.to_lower(name) Bool.or(String.eq(lowered, "host"), Bool.or(String.eq(lowered, "content-length"), Bool.or(String.eq(lowered, "transfer-encoding"), Bool.or(String.eq(lowered, "connection"), Bool.or(String.eq(lowered, "accept-encoding"), Bool.or(String.eq(lowered, "expect"), Bool.or(String.eq(lowered, "upgrade"), String.eq(lowered, "trailer"))))))))def validate_header_field_flags(name_ok: Bool, reserved: Bool, value_ok: Bool) -> Result<&1, &1, Error, Unit>: match name_ok reserved value_ok: case False{} _ _: Fail{InvalidHeader{}} case True{} True{} _: Fail{ReservedHeader{}} case True{} False{} False{}: Fail{InvalidHeader{}} case True{} False{} True{}: Done{Unit{}}def validate_header_field(+name: String, value: List<&2, U32>) -> Result<&1, &1, Error, Unit>: validate_header_field_flags(valid_header_name(name), reserved_header(name), valid_header_value_bytes(value))def validate_header_then(name: String, value: List<&2, U32>, result: Result<&1, &1, Error, Unit>) -> Result<&1, &1, Error, Unit>: match result: case Fail{error}: Fail{error} case Done{Unit{}}: validate_header_field(name, value)def validate_headers(headers: List<&2, Header>) -> Result<&1, &1, Error, Unit>: match headers: case Nil{}: Done{Unit{}} case Header{name, value} <> rest: validate_header_then(name, value, validate_headers(rest))def encode_headers(headers: List<&2, Header>) -> List<&2, U32>: match headers: case Nil{}: Nil{} case Header{name, value} <> rest: append_bytes(append_bytes(append_bytes(append_bytes(utf8(name), utf8(": ")), value), utf8("\r\n")), encode_headers(rest))def encode_length_header_if(method: String, body: List<&2, U32>, include: Bool) -> List<&2, U32>: match include: case False{}: Nil{} case True{}: utf8("Content-Length: " ++ Nat.show(List.length(&2, U32, body)) ++ "\r\n")def encode_length_header(+method: String, +body: List<&2, U32>) -> List<&2, U32>: encode_length_header_if(method, body, Bool.or(method_has_length(method), Bool.not(List.is_empty(&2, U32, body))))def encode_request_target(+method: String, target: Target, headers: List<&2, Header>, +body: List<&2, U32>) -> List<&2, U32>: Target{tls, host, port, authority, resource} = target append_bytes(utf8(method ++ " " ++ resource ++ " HTTP/1.1\r\nHost: " ++ authority ++ "\r\n"), append_bytes(encode_headers(headers), append_bytes(encode_length_header(method, body), append_bytes(utf8("Accept-Encoding: identity\r\nConnection: close\r\n\r\n"), body))))def encode_after_headers(method: String, target: Target, headers: List<&2, Header>, body: List<&2, U32>, result: Result<&1, &1, Error, Unit>) -> Result<&2, &2, Error, List<&2, U32>>: match result: case Fail{error}: Fail{error} case Done{Unit{}}: Done{encode_request_target(method, target, headers, body)}def encode_checked(method: String, target: Target, headers: List<&2, Header>, body: List<&2, U32>, method_ok: Bool, bytes_ok: Bool, header_result: Result<&1, &1, Error, Unit>) -> Result<&2, &2, Error, List<&2, U32>>: match method_ok bytes_ok: case False{} _: Fail{InvalidMethod{}} case True{} False{}: Fail{InvalidByte{}} case True{} True{}: encode_after_headers(method, target, headers, body, header_result)def encode_validated(method: String, target: Target, +headers: List<&2, Header>, body: List<&2, U32>, method_ok: Bool, bytes_ok: Bool) -> Result<&2, &2, Error, List<&2, U32>>: encode_checked(method, target, headers, body, method_ok, bytes_ok, validate_headers(headers))def encode_url_result(method: String, headers: List<&2, Header>, body: List<&2, U32>, parsed: Result<&2, &2, Error, Target>, method_ok: Bool, bytes_ok: Bool) -> Result<&2, &2, Error, List<&2, U32>>: match parsed: case Fail{error}: Fail{error} case Done{target}: encode_validated(method, target, headers, body, method_ok, bytes_ok)def encode(request: Request) -> Result<&2, &2, Error, List<&2, U32>>: Request{+method, +url, +headers, +body} = request encode_url_result(method, headers, body, parse_url(url), valid_method(method), valid_bytes(body))def octets_string(bytes: List<&2, U32>) -> String: match bytes: case Nil{}: SNil{} case h <> t: SCon{Chr{h}, octets_string(t)}def string_octets(text: String) -> List<&2, U32>: match text: case SNil{}: Nil{} case SCon{Chr{h}, t}: h <> string_octets(t)def dec_line(text: String, acc: String) -> Cut: match text: case SNil{}: CutMore{} case SCon{'\n', _}: CutBad{} case SCon{'\r', rest}: match rest: case SNil{}: CutMore{} case SCon{'\n', tail}: CutFound{acc, tail} case _: CutBad{} case SCon{h, t}: dec_line(t, acc ++ SCon{h, SNil{}})def dec_colon(text: String, acc: String) -> Cut: match text: case SNil{}: CutBad{} case SCon{':', rest}: CutFound{acc, rest} case SCon{h, t}: dec_colon(t, acc ++ SCon{h, SNil{}})def dec_trim_left(text: String) -> String: match text: case SCon{' ', t}: dec_trim_left(t) case SCon{'\t', t}: dec_trim_left(t) case _: textdef dec_trim_right(text: String) -> String: String.reverse(dec_trim_left(String.reverse(text)))def dec_header_value_checked(name: String, bytes: List<&2, U32>, valid: Bool) -> Result<&2, &2, Error, Header>: match valid: case True{}: Done{Header{name, bytes}} case False{}: Fail{InvalidHeader{}}def dec_header_name_checked(name: String, value: String, valid_name: Bool) -> Result<&2, &2, Error, Header>: match valid_name: case False{}: Fail{InvalidHeader{}} case True{}: +trimmed = dec_trim_right(dec_trim_left(value)) dec_header_value_checked(name, string_octets(trimmed), valid_header_value_bytes(string_octets(trimmed)))def dec_header_from_parts(+name: String, value: String, valid_name: Bool) -> Result<&2, &2, Error, Header>: dec_header_name_checked(name, value, valid_name)def dec_header_colon(+text: String, colon: Cut) -> Result<&2, &2, Error, Header>: match colon: case CutBad{}: Fail{InvalidHeader{}} case CutFound{+name, value}: dec_header_from_parts(name, value, valid_header_name(name)) case _: Fail{InvalidHeader{}}def dec_header_leading(+original: String, text: String) -> Result<&2, &2, Error, Header>: match text: case SCon{' ', _}: Fail{InvalidHeader{}} case SCon{'\t', _}: Fail{InvalidHeader{}} case _: dec_header_colon(original, dec_colon(original, SNil{}))def dec_header(+text: String) -> Result<&2, &2, Error, Header>: dec_header_leading(text, text)def dec_status_valid(status: U32, in_range: Bool) -> StatusLine: match in_range: case True{}: StatusOk{status} case False{}: StatusBad{InvalidStatus{}}def is_decimal_digit(c: Char) -> Bool: match c: case '0': True{} case '1': True{} case '2': True{} case '3': True{} case '4': True{} case '5': True{} case '6': True{} case '7': True{} case '8': True{} case '9': True{} case _: False{}def digit_value(c: Char) -> U32: U32.sub(Char.to_u32(c), 48)def dec_status_range(code: U32, valid: Bool) -> StatusLine: dec_status_valid(code, valid)def dec_status_digit_checks(a: Char, b: Char, c: Char, digits: Bool) -> StatusLine: match digits: case False{}: StatusBad{InvalidStatus{}} case True{}: +code = (digit_value(a) * 100 + digit_value(b) * 10 + digit_value(c) : U32) dec_status_range(code, Bool.and(U32.is_le(100, code), U32.is_le(code, 599)))def dec_status_digits(+a: Char, +b: Char, +c: Char) -> StatusLine: dec_status_digit_checks(a, b, c, Bool.and(is_decimal_digit(a), Bool.and(is_decimal_digit(b), is_decimal_digit(c))))def dec_status_line_space_char(tail: String, a: Char, b: Char, c: Char) -> StatusLine: match tail: case SCon{' ', _}: dec_status_digits(a, b, c) case _: StatusBad{InvalidStatus{}}def dec_status_line_space(tail: String, a: Char, b: Char, c: Char, empty: Bool) -> StatusLine: match empty: case True{}: dec_status_digits(a, b, c) case False{}: dec_status_line_space_char(tail, a, b, c)def dec_status_line_code(rest: String) -> StatusLine: match rest: case SCon{a, SCon{b, SCon{c, +tail}}}: dec_status_line_space(tail, a, b, c, String.is_empty(tail)) case _: StatusBad{InvalidStatus{}}def dec_status_line_version(line: String, is_v11: Bool) -> StatusLine: match is_v11: case False{}: StatusBad{InvalidVersion{}} case True{}: dec_status_line_code(String.drop(line, 9n))def dec_status_line(+line: String) -> StatusLine: dec_status_line_version(line, Bool.or(String.starts_with(line, "HTTP/1.1 "), String.starts_with(line, "HTTP/1.0 ")))def dec_step_finish(status: StatusLine, headers: List<&2, Header>, rest: String, size: Nat) -> HeadStep: match status: case StatusBad{error}: HeadStepBad{error} case StatusOk{code}: HeadStepDone{code, List.reverse(&2, Header, headers), rest, size}def dec_step_status(rest: String, headers: List<&2, Header>, size: Nat, count: Nat, parsed: StatusLine) -> HeadStep: match parsed: case StatusBad{error}: HeadStepBad{error} case StatusOk{code}: HeadContinue{rest, StatusOk{code}, headers, size, count}def dec_step_header(rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, parsed: Result<&2, &2, Error, Header>) -> HeadStep: match parsed: case Fail{error}: HeadStepBad{error} case Done{header}: HeadContinue{rest, status, header <> headers, size, (count + 1n : Nat)}def dec_step_count(line: String, rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, limits: Limits, within: Bool) -> HeadStep: match within: case False{}: HeadStepBad{LimitExceeded{}} case True{}: dec_step_header(rest, status, headers, size, count, dec_header(line))def dec_limits_header_count(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits header_countdef dec_limits_header_bytes(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits header_bytesdef dec_step_line_count(line: String, rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, +count: Nat, limits: Limits, header_limit: U32) -> HeadStep: dec_step_count(line, rest, status, headers, size, count, limits, Nat.is_le((count + 1n : Nat), U32.to_nat(header_limit)))def dec_step_line(line: String, rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, +limits: Limits) -> HeadStep: match status: case StatusBad{_}: dec_step_status(rest, headers, size, count, dec_status_line(line)) case StatusOk{_}: dec_step_line_count(line, rest, status, headers, size, count, limits, dec_limits_header_count(limits))def dec_step_blank(line: String, rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, limits: Limits, blank: Bool) -> HeadStep: match blank: case True{}: dec_step_finish(status, headers, rest, size) case False{}: dec_step_line(line, rest, status, headers, size, count, limits)def dec_step_size(+line: String, rest: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, limits: Limits, within: Bool) -> HeadStep: match within: case False{}: HeadStepBad{LimitExceeded{}} case True{}: dec_step_blank(line, rest, status, headers, size, count, limits, String.is_empty(line))def dec_step_cut(line_result: Cut, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, +limits: Limits) -> HeadStep: match line_result: case CutMore{}: HeadStepMore{} case CutBad{}: HeadStepBad{InvalidFraming{}} case CutFound{+line, rest}: +new_size = (size + String.length(line) + 2n : Nat) dec_step_size(line, rest, status, headers, new_size, count, limits, Nat.is_le(new_size, U32.to_nat(dec_limits_header_bytes(limits))))def dec_scan(fuel: Nat, text: String, status: StatusLine, headers: List<&2, Header>, size: Nat, count: Nat, +limits: Limits, step: HeadStep) -> HeadScan: match fuel: case 0n: HeadMore{} case 1n+p: match step: case HeadStepMore{}: HeadMore{} case HeadStepBad{error}: HeadBad{error} case HeadStepDone{code, parsed_headers, rest, head_size}: HeadDone{code, parsed_headers, rest, head_size} case HeadContinue{+rest, +next_status, +next_headers, +next_size, +next_count}: dec_scan(p, rest, next_status, next_headers, next_size, next_count, limits, dec_step_cut(dec_line(rest, SNil{}), next_status, next_headers, next_size, next_count, limits))def dec_parse_head(+text: String, +limits: Limits) -> HeadScan: dec_scan(String.length(text), text, StatusBad{InvalidStatus{}}, Nil{}, 0n, 0n, limits, dec_step_cut(dec_line(text, SNil{}), StatusBad{InvalidStatus{}}, Nil{}, 0n, 0n, limits))type DecLength is Data: DecNoLength{} DecHasLength{value: U32} DecLengthBad{error: Error}type RxNumber is Data: RxNumberOk{value: U32} RxNumberBad{} RxNumberOverflow{}def dec_decimal_overflow(okay: Bool, parsed: RxNumber) -> RxNumber: match okay: case False{}: RxNumberOverflow{} case True{}: parseddef dec_decimal(text: String, +value: U32, seen: Bool) -> RxNumber: match text: case SNil{}: match seen: case True{}: RxNumberOk{value} case False{}: RxNumberBad{} case SCon{'0', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967295, 10)), dec_decimal(rest, U32.mul(value, 10), True{})) case SCon{'1', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967294, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 1), True{})) case SCon{'2', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967293, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 2), True{})) case SCon{'3', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967292, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 3), True{})) case SCon{'4', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967291, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 4), True{})) case SCon{'5', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967290, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 5), True{})) case SCon{'6', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967289, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 6), True{})) case SCon{'7', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967288, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 7), True{})) case SCon{'8', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967287, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 8), True{})) case SCon{'9', rest}: dec_decimal_overflow(U32.is_le(value, U32.div(4294967286, 10)), dec_decimal(rest, U32.add(U32.mul(value, 10), 9), True{})) case _: RxNumberBad{}def dec_length_parsed(parsed: RxNumber) -> DecLength: match parsed: case RxNumberOk{value}: DecHasLength{value} case RxNumberBad{}: DecLengthBad{InvalidFraming{}} case RxNumberOverflow{}: DecLengthBad{LimitExceeded{}}def dec_length_exact(rest: List<&2, List<&2, U32>>, value: List<&2, U32>) -> DecLength: match rest: case Nil{}: dec_length_parsed(dec_decimal(octets_string(value), 0, False{})) case _: DecLengthBad{InvalidFraming{}}def dec_length_values(values: List<&2, List<&2, U32>>) -> DecLength: match values: case Nil{}: DecNoLength{} case value <> rest: dec_length_exact(rest, value)def dec_length(headers: List<&2, Header>) -> DecLength: dec_length_values(field_values("content-length", headers))def dec_no_body(+method: String, +status: U32) -> Bool: Bool.or(String.eq(method, "HEAD"), Bool.or(U32.is_eq(status, 204), U32.is_eq(status, 304)))def dec_take_enough(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +length: U32, enough: Bool) -> Decode: match enough: case False{}: NeedMore{} case True{}: Parsed{Response{status, headers, List.take(&2, U32, bytes, U32.to_nat(length)), Nil{}}, List.drop(&2, U32, bytes, U32.to_nat(length))}def dec_take_body(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +length: U32, within: Bool) -> Decode: match within: case False{}: Rejected{LimitExceeded{}} case True{}: dec_take_enough(status, headers, bytes, length, Nat.is_le(U32.to_nat(length), List.length(&2, U32, bytes)))type DecBodyState is Data: DecBodyComplete{} DecBodyTruncated{} DecBodyPartial{}def dec_body_state(+enough: Bool, +closed: Bool) -> DecBodyState: Bool.pick(DecBodyState, enough, DecBodyComplete{}, Bool.pick(DecBodyState, closed, DecBodyTruncated{}, DecBodyPartial{}))def dec_body_length_enough(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +value: U32, state: DecBodyState) -> Decode: match state: case DecBodyComplete{}: Parsed{Response{status, headers, List.take(&2, U32, bytes, U32.to_nat(value)), Nil{}}, List.drop(&2, U32, bytes, U32.to_nat(value))} case DecBodyTruncated{}: Rejected{UnexpectedEof{}} case DecBodyPartial{}: NeedMore{}def dec_body_length_dispatch(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +value: U32, +eof: Bool, limits: Limits, within: Bool) -> Decode: match within: case False{}: Rejected{LimitExceeded{}} case True{}: dec_body_length_enough(status, headers, bytes, value, dec_body_state( Nat.is_le(U32.to_nat(value), List.length(&2, U32, bytes)), eof))def dec_body_length_field(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +value: U32, +eof: Bool, limits: Limits, body_limit: U32) -> Decode: dec_body_length_dispatch(status, headers, bytes, value, eof, limits, U32.is_le(value, body_limit))def dec_limits_body_bytes(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits body_bytesdef dec_body_length(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +value: U32, +eof: Bool, +limits: Limits) -> Decode: dec_body_length_field(status, headers, bytes, value, eof, limits, dec_limits_body_bytes(limits))def dec_body_close(status: U32, headers: List<&2, Header>, bytes: List<&2, U32>, eof: Bool, within: Bool) -> Decode: match eof within: case False{} _: NeedMore{} case True{} False{}: Rejected{LimitExceeded{}} case True{} True{}: Parsed{Response{status, headers, bytes, Nil{}}, Nil{}}def dec_body_framing(method: String, status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +eof: Bool, +limits: Limits, framing: DecLength) -> Decode: match framing: case DecLengthBad{error}: Rejected{error} case DecHasLength{value}: dec_body_length(status, headers, bytes, value, eof, limits) case DecNoLength{}: dec_body_close(status, headers, bytes, eof, Nat.is_le(List.length(&2, U32, bytes), U32.to_nat(dec_limits_body_bytes(limits))))type ChunkSize is Data: ChunkSizeOk{value: U32} ChunkSizeBad{error: Error}type ChunkResult is Data: ChunkNeedMore{} ChunkBad{error: Error} ChunkDone{body: List<&2, U32>, trailers: List<&2, Header>, rest: String}def dec_hex_digit(c: Char) -> RxNumber: match c: case '0': RxNumberOk{0} case '1': RxNumberOk{1} case '2': RxNumberOk{2} case '3': RxNumberOk{3} case '4': RxNumberOk{4} case '5': RxNumberOk{5} case '6': RxNumberOk{6} case '7': RxNumberOk{7} case '8': RxNumberOk{8} case '9': RxNumberOk{9} case 'a': RxNumberOk{10} case 'b': RxNumberOk{11} case 'c': RxNumberOk{12} case 'd': RxNumberOk{13} case 'e': RxNumberOk{14} case 'f': RxNumberOk{15} case 'A': RxNumberOk{10} case 'B': RxNumberOk{11} case 'C': RxNumberOk{12} case 'D': RxNumberOk{13} case 'E': RxNumberOk{14} case 'F': RxNumberOk{15} case _: RxNumberBad{}def dec_hex_accum_check(value: U32, n: U32, okay: Bool) -> RxNumber: match okay: case True{}: RxNumberOk{U32.add(U32.mul(value, 16), n)} case False{}: RxNumberOverflow{}def dec_hex_accum(+value: U32, digit: RxNumber) -> RxNumber: match digit: case RxNumberOk{+n}: dec_hex_accum_check(value, n, U32.is_le(value, U32.div(U32.sub(4294967295, n), 16))) case _: digitdef dec_hex_number(+text: String, accumulator: RxNumber, seen: Bool) -> RxNumber: match text: case SNil{}: match accumulator: case RxNumberOk{value}: match seen: case True{}: RxNumberOk{value} case False{}: RxNumberBad{} case _: accumulator case SCon{c, rest}: match accumulator: case RxNumberOk{+value}: dec_hex_number(rest, dec_hex_accum(value, dec_hex_digit(c)), True{}) case _: accumulatordef dec_semicolon(text: String, acc: String) -> Cut: match text: case SNil{}: CutBad{} case SCon{';', rest}: CutFound{acc, rest} case SCon{h, t}: dec_semicolon(t, acc ++ SCon{h, SNil{}})def dec_chunk_size_number(parsed: RxNumber) -> ChunkSize: match parsed: case RxNumberOk{value}: ChunkSizeOk{value} case RxNumberBad{}: ChunkSizeBad{InvalidFraming{}} case RxNumberOverflow{}: ChunkSizeBad{LimitExceeded{}}def dec_chunk_size_split(line: String, split: Cut) -> ChunkSize: match split: case CutFound{size, _}: dec_chunk_size_number(dec_hex_number(size, RxNumberOk{0}, False{})) case _: dec_chunk_size_number(dec_hex_number(line, RxNumberOk{0}, False{}))def dec_chunk_size_check(line: String, split: Cut, within: Bool) -> ChunkSize: match within: case False{}: ChunkSizeBad{LimitExceeded{}} case True{}: dec_chunk_size_split(line, split)def dec_chunk_size(+line: String, line_limit: U32) -> ChunkSize: dec_chunk_size_check(line, dec_semicolon(line, SNil{}), Nat.is_le(String.length(line), U32.to_nat(line_limit)))type ChunkStep is Data: ChunkContinue{rest: String, body: List<&2, U32>, trailers: List<&2, Header>, trailer_bytes: Nat, trailer_count: Nat} ChunkStepNeed{} ChunkStepBad{error: Error} ChunkStepDone{body: List<&2, U32>, trailers: List<&2, Header>, rest: String}def dec_limits_chunk_line(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits chunk_line_bytesdef dec_limits_trailer_bytes(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits trailer_bytesdef dec_limits_trailer_count(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits trailer_countdef dec_trailer_forbidden_basic(+name: String) -> Bool: Bool.or(String.eq(String.to_lower(name), "content-length"), Bool.or(String.eq(String.to_lower(name), "transfer-encoding"), Bool.or(String.eq(String.to_lower(name), "host"), String.eq(String.to_lower(name), "trailer"))))def dec_trailer_forbidden_connection(+name: String) -> Bool: Bool.or(String.eq(String.to_lower(name), "connection"), Bool.or(String.eq(String.to_lower(name), "keep-alive"), String.eq(String.to_lower(name), "upgrade")))def dec_trailer_forbidden_proxy(+name: String) -> Bool: Bool.or(String.eq(String.to_lower(name), "te"), Bool.or(String.eq(String.to_lower(name), "proxy-authenticate"), String.eq(String.to_lower(name), "proxy-authorization")))def dec_trailer_forbidden(+name: String) -> Bool: Bool.or(dec_trailer_forbidden_basic(name), Bool.or(dec_trailer_forbidden_connection(name), dec_trailer_forbidden_proxy(name)))def dec_trailer_header_check(+header: Header, name: String, trailers: List<&2, Header>, +rest: String, trailer_bytes: Nat, trailer_count: Nat, forbidden: Bool) -> ChunkStep: match forbidden: case True{}: ChunkStepBad{InvalidFraming{}} case False{}: ChunkContinue{rest, Nil{}, append_headers(trailers, [header]), trailer_bytes, trailer_count}def dec_trailer_header(+header: Header, trailers: List<&2, Header>, +rest: String, trailer_bytes: Nat, trailer_count: Nat) -> ChunkStep: match header: case Header{name, value}: dec_trailer_header_check(header, name, trailers, rest, trailer_bytes, trailer_count, dec_trailer_forbidden(name))def dec_trailer_added_result(parsed: Result<&2, &2, Error, Header>, trailers: List<&2, Header>, +rest: String, trailer_bytes: Nat, trailer_count: Nat) -> ChunkStep: match parsed: case Fail{error}: ChunkStepBad{error} case Done{+header}: dec_trailer_header(header, trailers, rest, trailer_bytes, trailer_count)def dec_trailer_added(parsed: Result<&2, &2, Error, Header>, trailers: List<&2, Header>, +rest: String, trailer_bytes: Nat, trailer_count: Nat, limits: Limits, within: Bool) -> ChunkStep: match within: case False{}: ChunkStepBad{LimitExceeded{}} case True{}: dec_trailer_added_result(parsed, trailers, rest, trailer_bytes, trailer_count)def dec_trailer_blank(trailers: List<&2, Header>, +rest: String, trailer_bytes: Nat, limits: Limits, within: Bool) -> ChunkStep: match within: case True{}: ChunkStepDone{Nil{}, trailers, rest} case False{}: ChunkStepBad{LimitExceeded{}}def dec_trailer_line_empty(+line: String, +rest: String, trailers: List<&2, Header>, +trailer_bytes: Nat, +trailer_count: Nat, +limits: Limits, empty: Bool) -> ChunkStep: match empty: case True{}: dec_trailer_blank(trailers, rest, trailer_bytes, limits, Nat.is_le((trailer_bytes + 2n : Nat), U32.to_nat(dec_limits_trailer_bytes(limits)))) case False{}: dec_trailer_added(dec_header(line), trailers, rest, (trailer_bytes + String.length(line) + 2n : Nat), (trailer_count + 1n : Nat), limits, Bool.and(Nat.is_le((trailer_bytes + String.length(line) + 2n : Nat), U32.to_nat(dec_limits_trailer_bytes(limits))), Nat.is_le((trailer_count + 1n : Nat), U32.to_nat(dec_limits_trailer_count(limits)))))def dec_trailer_line(+line: String, rest: String, trailers: List<&2, Header>, trailer_bytes: Nat, trailer_count: Nat, limits: Limits) -> ChunkStep: dec_trailer_line_empty(line, rest, trailers, trailer_bytes, trailer_count, limits, String.is_empty(line))def dec_chunk_incomplete(eof: Bool) -> ChunkResult: match eof: case True{}: ChunkBad{UnexpectedEof{}} case False{}: ChunkNeedMore{}def dec_trailer_line_scan_result(+text: String, trailers: List<&2, Header>, trailer_bytes: Nat, trailer_count: Nat, limits: Limits, eof: Bool, cut: Cut) -> ChunkStep: match cut: case CutMore{}: ChunkStepNeed{} case CutBad{}: ChunkStepBad{InvalidFraming{}} case CutFound{line, rest}: dec_trailer_line(line, rest, trailers, trailer_bytes, trailer_count, limits)def dec_trailer_line_scan(+text: String, trailers: List<&2, Header>, +trailer_bytes: Nat, +trailer_count: Nat, +limits: Limits, eof: Bool) -> ChunkStep: dec_trailer_line_scan_result(text, trailers, trailer_bytes, trailer_count, limits, eof, dec_line(text, SNil{}))def dec_trailer_scan(fuel: Nat, +text: String, trailers: List<&2, Header>, +trailer_bytes: Nat, +trailer_count: Nat, +limits: Limits, +eof: Bool, step: ChunkStep) -> ChunkResult: match fuel: case 0n: ChunkNeedMore{} case 1n+p: match step: case ChunkStepNeed{}: dec_chunk_incomplete(eof) case ChunkStepBad{error}: ChunkBad{error} case ChunkStepDone{+body, +trailers, +rest}: ChunkDone{body, trailers, rest} case ChunkContinue{+rest, +body, +trailers, +next_bytes, +next_count}: dec_trailer_scan(p, rest, trailers, next_bytes, next_count, limits, eof, dec_trailer_line_scan(rest, trailers, next_bytes, next_count, limits, eof))def dec_trailer_step(body: List<&2, U32>, result: ChunkResult) -> ChunkStep: match result: case ChunkNeedMore{}: ChunkStepNeed{} case ChunkBad{error}: ChunkStepBad{error} case ChunkDone{_, trailers, rest}: ChunkStepDone{body, trailers, rest}def dec_chunk_data_terminator(+size: U32, body: List<&2, U32>, trailers: List<&2, Header>, +tail: String, data: String, valid: Bool) -> ChunkStep: match valid: case False{}: ChunkStepBad{InvalidFraming{}} case True{}: ChunkContinue{String.drop(tail, 2n), append_bytes(body, string_octets(data)), trailers, 0n, 0n}def dec_chunk_data_enough(+size: U32, body: List<&2, U32>, trailers: List<&2, Header>, +rest: String, limits: Limits, enough: Bool) -> ChunkStep: match enough: case False{}: ChunkStepNeed{} case True{}: data = String.take(rest, U32.to_nat(size)) +tail = String.drop(rest, U32.to_nat(size)) dec_chunk_data_terminator(size, body, trailers, tail, data, String.starts_with(tail, "\r\n"))def dec_chunk_data(+size: U32, body: List<&2, U32>, trailers: List<&2, Header>, +rest: String, +limits: Limits, within: Bool) -> ChunkStep: match within: case False{}: ChunkStepBad{LimitExceeded{}} case True{}: dec_chunk_data_enough(size, body, trailers, rest, limits, Nat.is_le((U32.to_nat(size) + 2n : Nat), String.length(rest)))def dec_chunk_size_zero(+size: U32, +body: List<&2, U32>, +trailers: List<&2, Header>, +rest: String, +limits: Limits, +eof: Bool, zero: Bool) -> ChunkStep: match zero: case False{}: dec_chunk_data(size, body, trailers, rest, limits, True{}) case True{}: dec_trailer_step(body, dec_trailer_scan((String.length(rest) + 1n : Nat), rest, trailers, 0n, 0n, limits, eof, dec_trailer_line_scan(rest, trailers, 0n, 0n, limits, eof)))def dec_chunk_size_ready(+size: U32, +body: List<&2, U32>, +trailers: List<&2, Header>, +rest: String, +limits: Limits, +eof: Bool, body_within: Bool) -> ChunkStep: match body_within: case False{}: ChunkStepBad{LimitExceeded{}} case True{}: dec_chunk_size_zero(size, body, trailers, rest, limits, eof, U32.is_eq(size, 0))def dec_chunk_size_limit(value: U32, body: List<&2, U32>, trailers: List<&2, Header>, +tail: String, +limits: Limits, eof: Bool, within: Bool) -> ChunkStep: dec_chunk_size_ready(value, body, trailers, tail, limits, eof, within)def dec_chunk_line_size(size: ChunkSize, +body: List<&2, U32>, +trailers: List<&2, Header>, +tail: String, +limits: Limits, +eof: Bool) -> ChunkStep: match size: case ChunkSizeBad{error}: ChunkStepBad{error} case ChunkSizeOk{+value}: dec_chunk_size_limit(value, body, trailers, tail, limits, eof, Nat.is_le((List.length(&2, U32, body) + U32.to_nat(value) : Nat), U32.to_nat(dec_limits_body_bytes(limits))))def dec_chunk_line_cut(+line: String, +tail: String, body: List<&2, U32>, trailers: List<&2, Header>, +limits: Limits, eof: Bool, size: ChunkSize, within: Bool) -> ChunkStep: match within: case False{}: ChunkStepBad{LimitExceeded{}} case True{}: dec_chunk_line_size(size, body, trailers, tail, limits, eof)def dec_chunk_line_scan_result(+text: String, +body: List<&2, U32>, +trailers: List<&2, Header>, +limits: Limits, +eof: Bool, cut: Cut) -> ChunkStep: match cut: case CutFound{+line, rest}: dec_chunk_line_cut(line, rest, body, trailers, limits, eof, dec_chunk_size(line, dec_limits_chunk_line(limits)), Nat.is_le((String.length(line) + 2n : Nat), U32.to_nat(dec_limits_chunk_line(limits)))) case CutMore{}: ChunkStepNeed{} case CutBad{}: ChunkStepBad{InvalidFraming{}}def dec_chunk_line_scan(+text: String, body: List<&2, U32>, trailers: List<&2, Header>, +limits: Limits, eof: Bool) -> ChunkStep: dec_chunk_line_scan_result(text, body, trailers, limits, eof, dec_line(text, SNil{}))def dec_chunk_scan(fuel: Nat, +text: String, body: List<&2, U32>, trailers: List<&2, Header>, +limits: Limits, +eof: Bool, step: ChunkStep) -> ChunkResult: match fuel: case 0n: ChunkNeedMore{} case 1n+p: match step: case ChunkStepNeed{}: dec_chunk_incomplete(eof) case ChunkStepBad{error}: ChunkBad{error} case ChunkStepDone{+body, +trailers, +rest}: ChunkDone{body, trailers, rest} case ChunkContinue{+rest, +body, +trailers, trailer_bytes, trailer_count}: dec_chunk_scan(p, rest, body, trailers, limits, eof, dec_chunk_line_scan(rest, body, trailers, limits, eof))def dec_chunked_result(status: U32, headers: List<&2, Header>, result: ChunkResult) -> Decode: match result: case ChunkNeedMore{}: NeedMore{} case ChunkBad{error}: Rejected{error} case ChunkDone{body, trailers, rest}: Parsed{Response{status, headers, body, trailers}, string_octets(rest)}def dec_chunked_decode(status: U32, headers: List<&2, Header>, +bytes: List<&2, U32>, +eof: Bool, +limits: Limits) -> Decode: +text = octets_string(bytes) dec_chunked_result(status, headers, dec_chunk_scan((String.length(text) + 1n : Nat), text, Nil{}, Nil{}, limits, eof, dec_chunk_line_scan(text, Nil{}, Nil{}, limits, eof)))def dec_transfer_value_check(status: U32, headers: List<&2, Header>, bytes: List<&2, U32>, eof: Bool, limits: Limits, is_chunked: Bool, repeated: Bool) -> Decode: match is_chunked: case True{}: dec_chunked_decode(status, headers, bytes, eof, limits) case False{}: match repeated: case True{}: Rejected{InvalidFraming{}} case False{}: Rejected{UnsupportedTransferEncoding{}}def dec_transfer_value_text(+status: U32, +headers: List<&2, Header>, +bytes: List<&2, U32>, +eof: Bool, +limits: Limits, +value: String) -> Decode: dec_transfer_value_check(status, headers, bytes, eof, limits, String.eq(value, "chunked"), String.eq(value, "chunked, chunked"))def dec_transfer_value(status: U32, headers: List<&2, Header>, bytes: List<&2, U32>, eof: Bool, limits: Limits, value: List<&2, U32>, framing: DecLength) -> Decode: match framing: case DecHasLength{_}: Rejected{InvalidFraming{}} case DecLengthBad{error}: Rejected{error} case DecNoLength{}: dec_transfer_value_text(status, headers, bytes, eof, limits, String.to_lower(octets_string(value)))def dec_transfer_pick(status: U32, headers: List<&2, Header>, bytes: List<&2, U32>, eof: Bool, limits: Limits, transfer: List<&2, List<&2, U32>>, framing: DecLength) -> Decode: match transfer: case Nil{}: dec_body_framing("GET", status, headers, bytes, eof, limits, framing) case value <> Nil{}: dec_transfer_value(status, headers, bytes, eof, limits, value, framing) case _ <> _: Rejected{InvalidFraming{}}def dec_transfer_for_method(method: String, status: U32, headers: List<&2, Header>, bytes: List<&2, U32>, eof: Bool, limits: Limits, transfer: List<&2, List<&2, U32>>, framing: DecLength) -> Decode: match transfer: case Nil{}: dec_body_framing(method, status, headers, bytes, eof, limits, framing) case value <> Nil{}: dec_transfer_value(status, headers, bytes, eof, limits, value, framing) case _ <> _: match framing: case DecHasLength{_}: Rejected{InvalidFraming{}} case DecLengthBad{error}: Rejected{error} case DecNoLength{}: Rejected{InvalidFraming{}}def dec_body_no_body(method: String, status: U32, +headers: List<&2, Header>, +bytes: List<&2, U32>, +eof: Bool, +limits: Limits, no_body: Bool) -> Decode: match no_body: case True{}: Parsed{Response{status, headers, Nil{}, Nil{}}, bytes} case False{}: dec_transfer_for_method(method, status, headers, bytes, eof, limits, field_values("transfer-encoding", headers), dec_length(headers))def dec_body_dispatch(+method: String, +status: U32, +headers: List<&2, Header>, +bytes: List<&2, U32>, +eof: Bool, +limits: Limits) -> Decode: dec_body_no_body(method, status, headers, bytes, eof, limits, dec_no_body(method, status))type DecAfterHead is Data: DecAfterMore{} DecAfterBad{error: Error} DecAfterInterim{rest: String} DecAfterFinal{result: Decode}def dec_status_is_interim(+status: U32) -> Bool: Bool.and(U32.is_le(100, status), Bool.and(U32.is_lt(status, 200), Bool.not(U32.is_eq(status, 101))))def dec_after_head_code(method: String, status: U32, headers: List<&2, Header>, rest: String, eof: Bool, limits: Limits, interim: Bool, upgrade: Bool) -> DecAfterHead: match interim upgrade: case True{} _: DecAfterInterim{rest} case False{} True{}: DecAfterBad{UnsupportedUpgrade{}} case False{} False{}: DecAfterFinal{dec_body_dispatch(method, status, headers, string_octets(rest), eof, limits)}def dec_after_head_step(method: String, head: HeadScan, eof: Bool, limits: Limits) -> DecAfterHead: match head: case HeadMore{}: match eof: case True{}: DecAfterBad{UnexpectedEof{}} case False{}: DecAfterMore{} case HeadBad{error}: DecAfterBad{error} case HeadDone{+status, headers, rest, head_size}: dec_after_head_code(method, status, headers, rest, eof, limits, dec_status_is_interim(status), U32.is_eq(status, 101))def dec_limits_interim_count(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits interim_countdef dec_after_head(fuel: Nat, +method: String, +limits: Limits, +eof: Bool, step: DecAfterHead) -> Decode: match fuel: case 0n: Rejected{LimitExceeded{}} case 1n+p: match step: case DecAfterMore{}: NeedMore{} case DecAfterBad{error}: Rejected{error} case DecAfterFinal{result}: result case DecAfterInterim{+rest}: dec_after_head(p, method, limits, eof, dec_after_head_step(method, dec_parse_head(rest, limits), eof, limits))def dec_decode_wire(+method: String, +limits: Limits, bytes: List<&2, U32>, +eof: Bool) -> Decode: text = octets_string(bytes) dec_after_head((U32.to_nat(dec_limits_interim_count(limits)) + 1n : Nat), method, limits, eof, dec_after_head_step(method, dec_parse_head(text, limits), eof, limits))def dec_limits_wire_bytes(limits: Limits) -> U32: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits wire_bytesdef dec_wire_parsed(response: Response, rest: List<&2, U32>, within: Bool) -> Decode: match within: case True{}: Parsed{response, rest} case False{}: Rejected{LimitExceeded{}}def dec_wire_incomplete(within: Bool) -> Decode: match within: case True{}: NeedMore{} case False{}: Rejected{LimitExceeded{}}def dec_decode_wire_result(result: Decode, +bytes: List<&2, U32>, limits: Limits) -> Decode: match result: case Parsed{response, +rest}: dec_wire_parsed(response, rest, Nat.is_le(Nat.sub(List.length(&2, U32, bytes), List.length(&2, U32, rest)), U32.to_nat(dec_limits_wire_bytes(limits)))) case NeedMore{}: dec_wire_incomplete(Nat.is_le(List.length(&2, U32, bytes), U32.to_nat(dec_limits_wire_bytes(limits)))) case Rejected{error}: Rejected{error}def dec_decode_bytes(method: String, +limits: Limits, +bytes: List<&2, U32>, eof: Bool, bytes_ok: Bool) -> Decode: match bytes_ok: case False{}: Rejected{InvalidByte{}} case True{}: dec_decode_wire_result(dec_decode_wire(method, limits, bytes, eof), bytes, limits)def decode(method: String, limits: Limits, +bytes: List<&2, U32>, eof: Bool) -> Decode: dec_decode_bytes(method, limits, bytes, eof, valid_bytes(bytes))def nonempty_fragments(parts: List<&2, List<&2, U32>>) -> List<&2, List<&2, U32>>: match parts: case Nil{}: Nil{} case Nil{} <> t: nonempty_fragments(t) case h <> t: h <> nonempty_fragments(t)def flatten_nonempty(parts: List<&2, List<&2, U32>>) -> List<&2, U32>: match parts: case Nil{}: Nil{} case h <> Nil{}: h case h <> t: append_bytes(h, flatten_nonempty(t))def flatten_bytes(parts: List<&2, List<&2, U32>>) -> List<&2, U32>: flatten_nonempty(nonempty_fragments(parts))def decode_parts(method: String, limits: Limits, fragments: List<&2, List<&2, U32>>, eof: Bool) -> Decode: decode(method, limits, flatten_bytes(fragments), eof)def drop_written_result(+bytes: List<&2, U32>, +count: U32, within: Bool, zero: Bool, empty: Bool) -> Result<&2, &2, Error, List<&2, U32>>: match within zero empty: case False{} _ _: Fail{InvalidFraming{}} case True{} True{} True{}: Done{Nil{}} case True{} True{} False{}: Fail{NoProgress{}} case True{} False{} _: Done{List.drop(&2, U32, bytes, U32.to_nat(count))}def drop_written(+bytes: List<&2, U32>, +count: U32) -> Result<&2, &2, Error, List<&2, U32>>: drop_written_result(bytes, count, Nat.is_le(U32.to_nat(count), List.length(&2, U32, bytes)), U32.is_eq(count, 0), List.is_empty(&2, U32, bytes))def read_json_parsed(parsed: Result<&1, &1, Json.Error, Json.Value>) -> Result<&1, &1, Error, Json.Value>: match parsed: case Done{value}: Done{value} case Fail{_}: Fail{InvalidJson{}}def read_json_body(body: List<&2, U32>, text: String, is_utf8: Bool) -> Result<&1, &1, Error, Json.Value>: match is_utf8: case False{}: Fail{InvalidUtf8{}} case True{}: read_json_parsed(Json.parse(text))def read_json_gpu_body(body: List<&2, U32>, text: String, is_utf8: Bool) -> Result<&1, &1, Error, Json.Value>: match is_utf8: case False{}: Fail{InvalidUtf8{}} case True{}: read_json_parsed(Json.parse_gpu(text))def read_json_select(+text: String, encoding_ok: Bool, is_utf8: Bool, gpu: Bool) -> Result<&1, &1, Error, Json.Value>: match encoding_ok is_utf8 gpu: case False{} _ _: Fail{UnsupportedContentEncoding{}} case True{} False{} _: Fail{InvalidUtf8{}} case True{} True{} False{}: read_json_parsed(Json.parse(text)) case True{} True{} True{}: read_json_parsed(Json.parse_gpu(text))def read_json_encoding(+body: List<&2, U32>, +text: String, encoding_ok: Bool) -> Result<&1, &1, Error, Json.Value>: read_json_select(text, encoding_ok, Bool.and(valid_bytes(body), byte_lists_equal(utf8(text), body)), False{})def identity_encoding(values: List<&2, List<&2, U32>>) -> Bool: match values: case Nil{}: True{} case value <> Nil{}: String.eq(String.to_lower(octets_string(value)), "identity") case _: False{}def read_json_encoding_gpu(+body: List<&2, U32>, +text: String, encoding_ok: Bool, gpu: Bool) -> Result<&1, &1, Error, Json.Value>: read_json_select(text, encoding_ok, Bool.and(valid_bytes(body), byte_lists_equal(utf8(text), body)), gpu)def read_json(response: Response) -> Result<&1, &1, Error, Json.Value>: Response{status, headers, +body, trailers} = response +values = field_values("content-encoding", headers) +text = Encoding.utf8.decode(Bytes.from_string(octets_string(body))) read_json_encoding(body, text, identity_encoding(values))def encode_gpu(request: Request) -> Result<&2, &2, Error, List<&2, U32>>: encode!(request)def decode_gpu(method: String, limits: Limits, bytes: List<&2, U32>, eof: Bool) -> Decode: decode!(method, limits, bytes, eof)def read_json_gpu(response: Response) -> Result<&1, &1, Error, Json.Value>: Response{status, headers, +body, trailers} = response +values = field_values("content-encoding", headers) +text = Encoding.utf8.decode(Bytes.from_string(octets_string(body))) read_json_encoding_gpu(body, text, identity_encoding(values), True{})def run_work(work: Work) -> Outcome: match work: case EncodeWork{request}: Encoded{encode(request)} case DecodeWork{method, limits, bytes, eof}: Decoded{decode(method, limits, bytes, eof)}def run_batch(batch: Batch) -> BatchResult: match batch: case Leaf{work}: LeafResult{run_work(work)} case Fork{left, right}: l r = run_batch(left) run_batch(right) ForkResult{l, r}def run_batch_gpu(batch: Batch) -> BatchResult: run_batch!(batch)def append_outcomes(xs: List<&2, Outcome>, ys: List<&2, Outcome>) -> List<&2, Outcome>: match xs: case Nil{}: ys case h <> t: h <> append_outcomes(t, ys)def batch_leaves(jobs: List<&2, Work>) -> List<&2, Batch>: match jobs: case Nil{}: Nil{} case job <> tail: Leaf{job} <> batch_leaves(tail)def batch_pairs(trees: List<&2, Batch>) -> List<&2, Batch>: match trees: case Nil{}: Nil{} case tree <> Nil{}: tree <> Nil{} case left <> right <> tail: Fork{left, right} <> batch_pairs(tail)def batch_fold_result(head: Batch, rest: Maybe<&2, Batch>) -> Maybe<&2, Batch>: match rest: case None{}: Some{head} case Some{tail}: Some{Fork{head, tail}}def batch_fold(trees: List<&2, Batch>) -> Maybe<&2, Batch>: match trees: case Nil{}: None{} case head <> tail: batch_fold_result(head, batch_fold(tail))def batch_build(fuel: Nat, trees: List<&2, Batch>) -> Maybe<&2, Batch>: match fuel: case 0n: batch_fold(trees) case 1n+p: match trees: case Nil{}: None{} case tree <> Nil{}: Some{tree} case left <> right <> tail: batch_build(p, batch_pairs(left <> right <> tail))def batch_from_list(+jobs: List<&2, Work>) -> Maybe<&2, Batch>: batch_build(List.length(&2, Work, jobs), batch_leaves(jobs))def run_many_tree(batch: Maybe<&2, Batch>) -> Maybe<&2, BatchResult>: match batch: case None{}: None{} case Some{tree}: Some{run_batch(tree)}def run_many_gpu_tree(batch: Maybe<&2, Batch>) -> Maybe<&2, BatchResult>: match batch: case None{}: None{} case Some{tree}: Some{run_batch_gpu(tree)}def run_many(jobs: List<&2, Work>) -> Maybe<&2, BatchResult>: run_many_tree(batch_from_list(jobs))def run_many_gpu(jobs: List<&2, Work>) -> Maybe<&2, BatchResult>: run_many_gpu_tree(batch_from_list(jobs))def flatten_results(results: BatchResult) -> List<&2, Outcome>: match results: case LeafResult{outcome}: [outcome] case ForkResult{left, right}: append_outcomes(flatten_results(left), flatten_results(right))def valid_limits(limits: Limits) -> Bool: Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, wire_bytes} = limits Bool.and(U32.is_ne(header_bytes, 0), Bool.and(U32.is_ne(header_count, 0), Bool.and(U32.is_ne(body_bytes, 0), Bool.and(U32.is_ne(trailer_bytes, 0), Bool.and(U32.is_ne(trailer_count, 0), Bool.and(U32.is_ne(interim_count, 0), Bool.and(U32.is_ne(chunk_line_bytes, 0), U32.is_ne(wire_bytes, 0))))))))def valid_options(options: Options) -> Bool: Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel} = options Bool.and(valid_limits(limits), Bool.and(U32.is_ne(connect_ms, 0), Bool.and(U32.is_ne(read_ms, 0), Bool.and(U32.is_ne(write_ms, 0), Bool.and(U32.is_ne(total_ms, 0), U32.is_ne(fuel, 0))))))def send_preflight_size(bytes: List<&2, U32>, within: Bool) -> Result<&1, &1, Error, List<&2, U32>>: match within: case True{}: Done{bytes} case False{}: Fail{LimitExceeded{}}def send_preflight_encoded(encoded: Result<&2, &2, Error, List<&2, U32>>, maximum: U32) -> Result<&1, &1, Error, List<&2, U32>>: match encoded: case Fail{error}: Fail{error} case Done{+bytes}: send_preflight_size(bytes, Nat.is_le(List.length(&2, U32, bytes), U32.to_nat(maximum)))# A character contributes at least one encoded byte. This rejects oversized# caller input before encode allocates the request; the exact byte cap follows.def send_header_input_size(headers: List<&2, Header>) -> Nat: match headers: case Nil{}: 0n case Header{name, value} <> rest: (String.length(name) + List.length(&2, U32, value) + send_header_input_size(rest) : Nat)def send_request_input_size(request: Request) -> Nat: match request: case Request{method, url, headers, body}: (String.length(method) + String.length(url) + send_header_input_size(headers) + List.length(&2, U32, body) : Nat)def send_request_header_count(request: Request) -> Nat: match request: case Request{method, url, headers, body}: List.length(&2, Header, headers)def send_preflight_status(options_valid: Bool, body_within: Bool, request: Request, maximum: U32) -> Result<&1, &1, Error, List<&2, U32>>: match options_valid: case False{}: Fail{Configuration{}} case True{}: match body_within: case False{}: Fail{LimitExceeded{}} case True{}: send_preflight_encoded(encode(request), maximum)def send_preflight_request(+request: Request, options_valid: Bool, limits: Limits) -> Result<&1, &1, Error, List<&2, U32>>: match request: case Request{method, url, headers, +body}: Limits{header_bytes, +header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, +wire_bytes} = limits send_preflight_status(options_valid, Bool.and(Nat.is_le(List.length(&2, U32, body), U32.to_nat(body_bytes)), Bool.and(Nat.is_le(send_request_input_size(request), U32.to_nat(wire_bytes)), Nat.is_le(send_request_header_count(request), U32.to_nat(header_count)))), request, wire_bytes)def send_preflight_options(+request: Request, options_valid: Bool, options: Options) -> Result<&1, &1, Error, List<&2, U32>>: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: send_preflight_request(request, options_valid, limits)def send_preflight(+request: Request, +options: Options) -> Result<&1, &1, Error, List<&2, U32>>: send_preflight_options(request, valid_options(options), options)def send_option_connect_ms(options: Options) -> U32: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: connect_msdef send_option_limits(options: Options) -> Limits: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: limitsdef send_option_read_ms(options: Options) -> U32: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: read_msdef send_option_write_ms(options: Options) -> U32: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: write_msdef send_option_total_ms(options: Options) -> U32: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: total_msdef send_option_fuel(options: Options) -> U32: match options: case Options{limits, connect_ms, read_ms, write_ms, total_ms, fuel}: fueldef send_error_timeout(is_timeout: Bool, fallback: Error) -> Error: match is_timeout: case True{}: Timeout{} case False{}: fallbackdef send_error_code(+code: U32, fallback: Error) -> Error: send_error_timeout(Bool.or(U32.is_eq(code, 110), U32.is_eq(code, 60)), fallback)def send_min_budget_choice(is_smaller: Bool, +remain: Nat, +maximum: U32) -> Maybe<&2, U32>: match is_smaller: case True{}: Some{maximum} case False{}: Some{U32.from_nat(remain)}def send_min_budget_status(is_before: Bool, +deadline: Nat, +maximum: U32, now: Nat) -> Maybe<&2, U32>: match is_before: case False{}: None{} case True{}: +remain = Nat.sub(deadline, now) send_min_budget_choice(Nat.is_lt(U32.to_nat(maximum), remain), remain, maximum)def send_min_budget(+deadline: Nat, +maximum: U32, +now: Nat) -> Maybe<&2, U32>: send_min_budget_status(Nat.is_lt(now, deadline), deadline, maximum, now)def send_budget(deadline: Nat, maximum: U32) -> IO(Maybe<&2, U32>): do IO<Maybe<&2, U32>>: now : Nat <- IO.now() return send_min_budget(deadline, maximum, now)def send_dns_target_local(+host: String, is_local: Bool, budget: U32) -> IO(Maybe<&2, String>): match is_local: case True{}: IO.pure(Maybe<&2, String>, Some{"127.0.0.1"}) case False{}: Dns.resolve.timeout(host, budget)def send_dns_target_kind(+host: String, is_ipv4: Bool, budget: U32) -> IO(Maybe<&2, String>): match is_ipv4: case True{}: IO.pure(Maybe<&2, String>, Some{host}) case False{}: send_dns_target_local(host, String.eq(host, "localhost"), budget)def send_dns_target(+host: String, budget: U32) -> IO(Maybe<&2, String>): send_dns_target_kind(host, Dns.ipv4(host), budget)def send_closed(tls: Bool, sock: Socket) -> IO(Unit): match tls: case True{}: Wire.tls.close(sock) case False{}: Socket.close(sock)def send_fail_closed(tls: Bool, sock: Socket, error: Error) -> IO(Result<&1, &1, Error, Response>): do IO<Result<&1, &1, Error, Response>>: send_closed(tls, sock) return Fail{error}def send_finish_closed(tls: Bool, sock: Socket, decoded: Decode) -> IO(Result<&1, &1, Error, Response>): match decoded: case Parsed{response, rest}: do IO<Result<&1, &1, Error, Response>>: send_closed(tls, sock) return Done{response} case Rejected{error}: send_fail_closed(tls, sock, error) case NeedMore{}: send_fail_closed(tls, sock, NoProgress{})def send_recv(+tls: Bool, sock: Socket, max: U32, ms: U32) -> IO(Socket & Result<&1, &1, U32 & String, String>): match tls: case True{}: Wire.tls.recv(sock, max, ms) case False{}: Wire.recv(sock, max, ms)def send_read_size_choice(small: Bool, limit: U32) -> U32: match small: case True{}: limit case False{}: 4096def send_read_size(limits: Limits) -> U32: match limits: case Limits{header_bytes, header_count, body_bytes, trailer_bytes, trailer_count, interim_count, chunk_line_bytes, +wire_bytes}: send_read_size_choice(U32.is_lt(wire_bytes, 4096), wire_bytes)def send_read_process_data(tls: Bool, sock: Socket, +method: String, +limits: Limits, +bytes: List<&2, U32>, +data: String, empty: Bool, resume: Socket -> List<&2, U32> -> IO(Result<&1, &1, Error, Response>)) -> IO(Result<&1, &1, Error, Response>): match empty: case True{}: send_finish_closed(tls, sock, decode(method, limits, bytes, True{})) case False{}: resume(sock, append_bytes(bytes, string_octets(data)))def send_read_process(tls: Bool, +method: String, +limits: Limits, +bytes: List<&2, U32>, resume: Socket -> List<&2, U32> -> IO(Result<&1, &1, Error, Response>), result: Socket & Result<&1, &1, U32 & String, String>) -> IO(Result<&1, &1, Error, Response>): (sock, read_result) = result match read_result: case Fail{(+code, message)}: send_fail_closed(tls, sock, send_error_code(code, Io{})) case Done{+data}: send_read_process_data(tls, sock, method, limits, bytes, data, String.is_empty(data), resume)def send_read_budget(+tls: Bool, sock: Socket, +method: String, +limits: Limits, +bytes: List<&2, U32>, read_ms: U32, budget: Maybe<&2, U32>, resume: Socket -> List<&2, U32> -> IO(Result<&1, &1, Error, Response>)) -> IO(Result<&1, &1, Error, Response>): match budget: case None{}: send_fail_closed(tls, sock, Timeout{}) case Some{ms}: do IO<Result<&1, &1, Error, Response>>: received : Socket & Result<&1, &1, U32 & String, String> <- send_recv(tls, sock, send_read_size(limits), ms) send_read_process(tls, method, limits, bytes, resume, received)def send_read_start(tls: Bool, sock: Socket, +method: String, +limits: Limits, +bytes: List<&2, U32>, +deadline: Nat, +read_ms: U32, resume: Socket -> List<&2, U32> -> IO(Result<&1, &1, Error, Response>)) -> IO(Result<&1, &1, Error, Response>): do IO<Result<&1, &1, Error, Response>>: budget : Maybe<&2, U32> <- send_budget(deadline, read_ms) send_read_budget(tls, sock, method, limits, bytes, read_ms, budget, resume)def send_read_decoded(tls: Bool, sock: Socket, +method: String, +limits: Limits, +bytes: List<&2, U32>, resume: Socket -> List<&2, U32> -> IO(Result<&1, &1, Error, Response>), decoded: Decode) -> IO(Result<&1, &1, Error, Response>): match decoded: case Parsed{response, rest}: send_finish_closed(tls, sock, Parsed{response, rest}) case Rejected{error}: send_fail_closed(tls, sock, error) case NeedMore{}: resume(sock, bytes)def send_read_step(fuel: Nat, +tls: Bool, sock: Socket, +method: String, +limits: Limits, +bytes: List<&2, U32>, +deadline: Nat, +read_ms: U32) -> IO(Result<&1, &1, Error, Response>): match fuel: case 0n: send_read_decoded(tls, sock, method, limits, bytes, next_sock => next_bytes => send_fail_closed(tls, next_sock, LimitExceeded{}), decode(method, limits, bytes, False{})) case 1n+left: send_read_decoded(tls, sock, method, limits, bytes, next_sock => next_bytes => send_read_start(tls, next_sock, method, limits, next_bytes, deadline, read_ms, after_sock => after_bytes => send_read_step(left, tls, after_sock, method, limits, after_bytes, deadline, read_ms)), decode(method, limits, bytes, False{}))def send_written_success(tls: Bool, sock: Socket, request: Request, +limits: Limits, deadline: Nat, read_ms: U32, fuel: U32) -> IO(Result<&1, &1, Error, Response>): match request: case Request{method, url, headers, body}: send_read_step(U32.to_nat(fuel), tls, sock, method, limits, Nil{}, deadline, read_ms)def send_written_result(tls: Bool, +request: Request, +limits: Limits, deadline: Nat, read_ms: U32, fuel: U32, result: Socket & Result<&1, &1, U32 & String, Unit>) -> IO(Result<&1, &1, Error, Response>): (sock, write_result) = result match write_result: case Fail{(+code, message)}: send_fail_closed(tls, sock, send_error_code(code, Io{})) case Done{Unit{}}: send_written_success(tls, sock, request, limits, deadline, read_ms, fuel)def send_wire_method(tls: Bool) -> Socket -> String -> U32 -> IO(Socket & Result<&1, &1, U32 & String, Unit>): match tls: case True{}: Wire.tls.send.timeout case False{}: Wire.send.timeoutdef send_socket_action(+tls: Bool, sock: Socket, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, read_ms: U32, fuel: U32, ms: U32) -> IO(Result<&1, &1, Error, Response>): do IO<Result<&1, &1, Error, Response>>: written : Socket & Result<&1, &1, U32 & String, Unit> <- send_wire_method(tls)(sock, octets_string(encoded), ms) send_written_result(tls, request, limits, deadline, read_ms, fuel, written)def send_socket_budget(tls: Bool, sock: Socket, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, write_ms: U32, read_ms: U32, fuel: U32, budget: Maybe<&2, U32>) -> IO(Result<&1, &1, Error, Response>): match budget: case None{}: send_fail_closed(tls, sock, Timeout{}) case Some{ms}: send_socket_action(tls, sock, request, encoded, limits, deadline, read_ms, fuel, ms)def send_socket(tls: Bool, sock: Socket, +request: Request, +encoded: List<&2, U32>, +limits: Limits, +deadline: Nat, +write_ms: U32, read_ms: U32, fuel: U32) -> IO(Result<&1, &1, Error, Response>): do IO<Result<&1, &1, Error, Response>>: budget : Maybe<&2, U32> <- send_budget(deadline, write_ms) send_socket_budget(tls, sock, request, encoded, limits, deadline, write_ms, read_ms, fuel, budget)def send_tls_result(+request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, write_ms: U32, read_ms: U32, fuel: U32, result: Socket & Result<&1, &1, U32 & String, Unit>) -> IO(Result<&1, &1, Error, Response>): (sock, tls_result) = result match tls_result: case Fail{(+code, message)}: do IO<Result<&1, &1, Error, Response>>: Socket.close(sock) return Fail{send_error_code(code, Tls{})} case Done{Unit{}}: send_socket(True{}, sock, request, encoded, limits, deadline, write_ms, read_ms, fuel)def send_tls_budget(sock: Socket, +host: String, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, write_ms: U32, read_ms: U32, fuel: U32, budget: Maybe<&2, U32>) -> IO(Result<&1, &1, Error, Response>): match budget: case None{}: do IO<Result<&1, &1, Error, Response>>: Socket.close(sock) return Fail{Timeout{}} case Some{ms}: do IO<Result<&1, &1, Error, Response>>: connected : Socket & Result<&1, &1, U32 & String, Unit> <- Wire.tls.connect(sock, host, ms) send_tls_result(request, encoded, limits, deadline, write_ms, read_ms, fuel, connected)def send_connected_fields(tls: Bool, +host: String, +request: Request, +encoded: List<&2, U32>, +limits: Limits, +deadline: Nat, +options: Options, sock: Socket) -> IO(Result<&1, &1, Error, Response>): match tls: case False{}: send_socket(False{}, sock, request, encoded, limits, deadline, send_option_write_ms(options), send_option_read_ms(options), send_option_fuel(options)) case True{}: do IO<Result<&1, &1, Error, Response>>: budget : Maybe<&2, U32> <- send_budget(deadline, send_option_connect_ms(options)) send_tls_budget(sock, host, request, encoded, limits, deadline, send_option_write_ms(options), send_option_read_ms(options), send_option_fuel(options), budget)def send_connected(+target: Target, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, options: Options, sock: Socket) -> IO(Result<&1, &1, Error, Response>): match target: case Target{tls, host, port, authority, resource}: send_connected_fields(tls, host, request, encoded, limits, deadline, options, sock)def send_connected_fields_result(tls: Bool, +host: String, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, options: Options, result: Result<&1, &1, U32 & String, Socket>) -> IO(Result<&1, &1, Error, Response>): match result: case Fail{(+code, message)}: IO.pure(Result<&1, &1, Error, Response>, Fail{send_error_code(code, Connection{})}) case Done{sock}: send_connected_fields(tls, host, request, encoded, limits, deadline, options, sock)def send_resolved_budget(tls: Bool, +host: String, port: U32, +authority: String, +resource: String, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, options: Options, +ip: String, budget: Maybe<&2, U32>) -> IO(Result<&1, &1, Error, Response>): match budget: case None{}: IO.pure(Result<&1, &1, Error, Response>, Fail{Timeout{}}) case Some{ms}: do IO<Result<&1, &1, Error, Response>>: result : Result<&1, &1, U32 & String, Socket> <- Wire.connect(ip, port, ms) send_connected_fields_result(tls, host, request, encoded, limits, deadline, options, result)def send_resolved(+target: Target, +request: Request, +encoded: List<&2, U32>, +limits: Limits, +deadline: Nat, +options: Options, ip: String) -> IO(Result<&1, &1, Error, Response>): match target: case Target{tls, host, port, authority, resource}: do IO<Result<&1, &1, Error, Response>>: budget : Maybe<&2, U32> <- send_budget(deadline, send_option_connect_ms(options)) send_resolved_budget(tls, host, port, authority, resource, request, encoded, limits, deadline, options, ip, budget)def send_connected_result(+target: Target, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, options: Options, result: Result<&1, &1, U32 & String, Socket>) -> IO(Result<&1, &1, Error, Response>): match result: case Fail{(+code, message)}: IO.pure(Result<&1, &1, Error, Response>, Fail{send_error_code(code, Connection{})}) case Done{sock}: send_connected(target, request, encoded, limits, deadline, options, sock)def send_dns_missing(budget: Maybe<&2, U32>) -> IO(Result<&1, &1, Error, Response>): match budget: case None{}: IO.pure(Result<&1, &1, Error, Response>, Fail{Timeout{}}) case Some{ms}: IO.pure(Result<&1, &1, Error, Response>, Fail{Connection{}})def send_dns_result(+target: Target, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, options: Options, result: Maybe<&2, String>) -> IO(Result<&1, &1, Error, Response>): match result: case None{}: do IO<Result<&1, &1, Error, Response>>: budget : Maybe<&2, U32> <- send_budget(deadline, send_option_connect_ms(options)) send_dns_missing(budget) case Some{ip}: send_resolved(target, request, encoded, limits, deadline, options, ip)def send_target_budget(+target: Target, +request: Request, +encoded: List<&2, U32>, +limits: Limits, deadline: Nat, options: Options, +host: String, budget: Maybe<&2, U32>) -> IO(Result<&1, &1, Error, Response>): match budget: case None{}: IO.pure(Result<&1, &1, Error, Response>, Fail{Timeout{}}) case Some{ms}: do IO<Result<&1, &1, Error, Response>>: ip : Maybe<&2, String> <- send_dns_target(host, ms) send_dns_result(target, request, encoded, limits, deadline, options, ip)def send_target(+target: Target, +request: Request, +encoded: List<&2, U32>, +limits: Limits, +deadline: Nat, +options: Options) -> IO(Result<&1, &1, Error, Response>): match target: case Target{tls, host, port, authority, resource}: do IO<Result<&1, &1, Error, Response>>: budget : Maybe<&2, U32> <- send_budget(deadline, send_option_connect_ms(options)) send_target_budget(target, request, encoded, limits, deadline, options, host, budget)def send_started_url(+request: Request, +options: Options, deadline: Nat, +encoded: List<&2, U32>, parsed: Result<&2, &2, Error, Target>) -> IO(Result<&1, &1, Error, Response>): match parsed: case Fail{error}: IO.pure(Result<&1, &1, Error, Response>, Fail{error}) case Done{target}: send_target(target, request, encoded, send_option_limits(options), deadline, options)def send_started_request(+request: Request, +options: Options, deadline: Nat, +encoded: List<&2, U32>) -> IO(Result<&1, &1, Error, Response>): match request: case Request{method, url, headers, body}: send_started_url(request, options, deadline, encoded, parse_url(url))def send_started(+request: Request, +options: Options, deadline: Nat, preflight: Result<&1, &1, Error, List<&2, U32>>) -> IO(Result<&1, &1, Error, Response>): match preflight: case Fail{error}: IO.pure(Result<&1, &1, Error, Response>, Fail{error}) case Done{encoded}: send_started_request(request, options, deadline, encoded)def send_started_at(+request: Request, +options: Options, preflight: Result<&1, &1, Error, List<&2, U32>>, now: Nat) -> IO(Result<&1, &1, Error, Response>): send_started(request, options, Nat.add(now, U32.to_nat(send_option_total_ms(options))), preflight)def send_selected(+request: Request, +options: Options, options_ok: Bool) -> IO(Result<&1, &1, Error, Response>): match options_ok: case False{}: IO.pure(Result<&1, &1, Error, Response>, Fail{Configuration{}}) case True{}: do IO<Result<&1, &1, Error, Response>>: now : Nat <- IO.now() send_started_at(request, options, send_preflight(request, options), now)def send(+request: Request, +options: Options) -> IO(Result<&1, &1, Error, Response>): send_selected(request, options, valid_options(options))