Crate parse_net 

parse_net

The grammar layer for Internet message fields: RFC 9110 field syntax, media types, RFC 9651 Structured Field Values, HTTP and RFC 5322 dates, content negotiation, entity tags, ranges, Content-Disposition with RFC 8187, Cache-Control, Link, Forwarded, authentication challenges, Host, Origin, and the email lexical layer, with safe writers for each.

Protocol engines (http-net, ws-net, h2-net) frame messages; parse-net reads what is inside a field value and writes field values back out without ever emitting CR, LF, or NUL. It is no_std, needs no allocator for any parse, does no I/O, and has no dependencies.

Tier 1

The convention in every example is use parse_net as pn;. One plain call per field:

use parse_net as pn;

// Media types: one strict view, no copy.
let mt = pn::parse_media_type(b"text/html; charset=UTF-8")?;
assert!(mt.essence_is("text/html"));
assert!(mt.charset().is_some_and(|c| c.eq_ignore_ascii_case(b"utf-8")));

// Lists: commas inside quoted strings and comments do not split.
let codings: Vec<&[u8]> = pn::list(b"gzip, deflate;q=0.5, x=\"a,b\"")?.iter().collect();
assert_eq!(codings, [&b"gzip"[..], b"deflate;q=0.5", b"x=\"a,b\""]);

// HTTP-date: all three formats in, IMF-fixdate out.
let now = 1_792_540_800; // the caller's clock, Unix seconds
let d = pn::http_date_at(b"Sunday, 06-Nov-94 08:49:37 GMT", now)?;
assert_eq!(&d.format(), b"Sun, 06 Nov 1994 08:49:37 GMT");

// Host: real IPv4 and IPv6 validation, ports up to 65535.
let hp = pn::parse_host_port(b"[2001:db8::1]:8443")?;
assert_eq!(hp.port, Some(8443));
assert!(pn::parse_host_port(b"127.1").is_err()); // read as IPv4 by browsers: refused

// Writers cannot emit CR, LF, or NUL.
let mut buf = [0u8; 64];
let mut out = pn::SliceSink::new(&mut buf);
pn::media::write("text", "plain", &[("charset", "utf-8")], &mut out)?;
assert_eq!(out.written(), b"text/plain; charset=utf-8");
assert!(pn::write::write_field_value(b"x\r\nSet-Cookie: y", &mut out).is_err());

Errors carry a kind and an offset, never input bytes:

use parse_net as pn;

let err = pn::parse_media_type(b"text/ html").unwrap_err();
assert_eq!(err.kind(), pn::ErrorKind::InvalidMediaType);
assert_eq!(err.to_string(), "invalid media type at offset 5");

The rest of Tier 1 arrives with 0.4.0 and 0.5.0 (see the roadmap):

pn::best_media(accept, &["text/html", "application/json"])    // Option<usize>
pn::if_none_match(if_none_match, &current_etag)?              // bool: answer 304
pn::byte_ranges(range, file_len, &mut buf)?                   // RangeOutcome
pn::parse_content_disposition(value)?.filename()              // prefers filename*
pn::response_cache_control(value)?                            // ResponseDirectives
pn::client_address(peer, pn::ForwardedSource::XForwardedFor(&lines), &trusted, 16)?
pn::sfv::parse_item(b"same-origin")?                          // Sec-Fetch-Site
pn::bearer(authorization)?                                    // Option<&[u8]>

Status

Feature complete, 0.5.0: the core, the web layer, links, Structured Field writing, and the email lexical layer. The public API is written down in docs/API.md, each field’s grammar in docs/GRAMMAR.md, the design in dev/PLAN.md, and the milestone schedule in dev/ROADMAP.md (all in the repository).

Re-exports

pub use auth::AuthPayload;

pub use auth::Challenge;

pub use auth::Credentials;

pub use auth::basic;

pub use auth::bearer;

pub use cache::Directive;

pub use cache::RequestDirectives;

pub use cache::ResponseDirectives;

pub use cache::request_cache_control;

pub use cache::response_cache_control;

pub use date::http_date;std

pub use date::Civil;

pub use date::DateFormat;

pub use date::HttpDate;

pub use date::MailDate;

pub use date::http_date_at;

pub use disposition::ContentDisposition;

pub use disposition::DispositionType;

pub use disposition::Filename;

pub use disposition::parse_content_disposition;

pub use disposition::write_attachment;

pub use etag::Condition;

pub use etag::EntityTag;

pub use etag::TagList;

pub use etag::if_match;

pub use etag::if_none_match;

pub use etag::parse_condition;

pub use ext_value::Charset;

pub use ext_value::ExtValue;

pub use ext_value::write_ext_value;

pub use forwarded::ClientAddress;

pub use forwarded::ForwardedSource;

pub use forwarded::Trust;

pub use forwarded::client_address;

pub use host::Host;

pub use host::HostPort;

pub use host::parse_host_port;

pub use link::LinkValue;

pub use link::Links;

pub use link::parse_link;

pub use list::List;

pub use list::list;

pub use media::Boundary;

pub use media::MediaRange;

pub use media::MediaType;

pub use media::parse_media_type;

pub use negotiate::QValue;

pub use negotiate::best_charset;

pub use negotiate::best_encoding;

pub use negotiate::best_language;

pub use negotiate::best_media;

pub use origin::Origin;

pub use origin::OriginValue;

pub use origin::parse_origin;

pub use param::Param;

pub use param::Params;

pub use range::ByteRange;

pub use range::ContentRange;

pub use range::IfRange;

pub use range::RangeHeader;

pub use range::RangeOutcome;

pub use range::RangeSpec;

pub use range::byte_ranges;

pub use text::Comment;

pub use text::Quoted;

pub use text::Word;

pub use write::CountSink;

pub use write::Sink;

pub use write::SliceSink;

Modules

auth

Authorization, Proxy-Authorization, WWW-Authenticate, and Proxy-Authenticate (RFC 9110 section 11), with the Bearer (RFC 6750) and Basic (RFC 7617) payloads.

cache

Cache-Control (RFC 9111 section 5.2, with immutable from RFC 8246 and stale-while-revalidate and stale-if-error from RFC 5861).

class

The byte classes of the ABNF, in one table.

date

The proleptic Gregorian calendar and HTTP-date (RFC 9110 section 5.6.7).

disposition

Content-Disposition (RFC 6266, and its use in multipart/form-data part headers, RFC 7578 section 4.2).

etag

Entity tags and the If-Match / If-None-Match conditions (RFC 9110 sections 8.8.3 and 13.1).

ext_value

RFC 8187 extended parameter values: charset "'" [ language ] "'" value-chars, as in filename* and title*.

forwarded

Forwarded (RFC 7239) and the de facto X-Forwarded-For, X-Forwarded-Proto, and X-Forwarded-Host, with client-address resolution through trusted proxies.

host

Host = uri-host [ ":" port ] (RFC 9110 section 7.2, citing RFC 3986 section 3.2.2), with real IPv4 and IPv6 validation.

link

Link (RFC 8288 section 3): #link-value, where link-value = "<" URI-Reference ">" *( OWS ";" OWS link-param ) and link-param = token BWS [ "=" BWS ( token / quoted-string ) ].

list

The #rule lists of RFC 9110 section 5.6.1, including several field lines read as one list (section 5.3).

mail

The email lexical layer (RFC 5322, RFC 2045, RFC 2047, RFC 2231): header lines and folding, encoded words, MIME parameters with continuations, addresses, and message identifiers. The grammar smtp-net needs to write mail and gate-net needs to validate login addresses (D-008); not a mail parser. Charsets decoded: UTF-8, US-ASCII, ISO-8859-1.

media

Media types: type "/" subtype parameters (RFC 9110 section 8.3.1), and the RFC 2046 multipart boundary.

negotiate

Content negotiation: quality values and the selection of the best offer for Accept, Accept-Language, Accept-Encoding, and Accept-Charset (RFC 9110 section 12, RFC 4647).

num

Decimal digits with overflow checks.

origin

Origin (RFC 6454 section 7): null or scheme "://" host [ ":" port ].

param

Parameters: *( OWS ";" OWS [ parameter ] ) (RFC 9110 section 5.6.6).

pct

The percent-encoding primitive: validate, decode into a caller buffer, and encode with a named set and hex case.

range

Range, Content-Range, and If-Range (RFC 9110 section 14), with resolution against a representation length and budgets against abusive range sets.

scan

Byte search and field-value validation, eight bytes per step.

sfv

Structured Field Values (RFC 9651): Items, Lists, and Dictionaries with every bare item type, parsed into borrowed views.

text

The lexical forms of RFC 9110 section 5.6: tokens, optional whitespace, quoted strings, words (token / quoted-string), and comments.

write

Output: the Sink trait, SliceSink, CountSink, and the writers for numbers, tokens, quoted strings, parameters, and field values.

Structs

Full

A sink has no room for the bytes it was given.

Limits

The work and size bounds every parser enforces.

OwnedEntityTagalloc

An owned EntityTag.

OwnedHostPortalloc

An owned HostPort.

OwnedMediaTypealloc

An owned MediaType.

ParseError

Why a value was refused, and where.

Enums

DuplicatePolicy

What a parameter parser does when a name repeats.

ErrorKind

What a parser refused.

WriteError

Why a writer refused.

Constants

VERSION

Crate version string, populated by Cargo at build time.