Crate mailrs_ical 

RFC 5545 (iCalendar) + RFC 5546 (iTIP) parser, serializer, and typed semantics — hand-rolled, zero I/O.

Built for Rust MTAs that need to read an iCalendar invite off the wire (typically a text/calendar MIME part) and emit a REPLY back. The parser is byte-by-byte with no parser-combinator dependencies — the same style as mailrs-smtp-proto and mailrs-imap-proto — keeping the dependency footprint small and the error surface predictable.

Quick start

use mailrs_ical::{parse_invite, Method};

let ics = b"BEGIN:VCALENDAR\r\nVERSION:2.0\r\nMETHOD:REQUEST\r\n\
            PRODID:-//Example//Cal//EN\r\nBEGIN:VEVENT\r\n\
            UID:abc\r\nDTSTAMP:20260101T000000Z\r\n\
            DTSTART:20260102T100000Z\r\nSUMMARY:Lunch\r\n\
            END:VEVENT\r\nEND:VCALENDAR\r\n";

let invite = parse_invite(ics).unwrap();
assert_eq!(invite.method, Method::Request);
assert_eq!(invite.uid, "abc");
assert_eq!(invite.summary, "Lunch");

Module layout

• parse — RFC 5545 §3.1 text → raw AST (line folding, property tree, BEGIN/END nesting).
• semantics — AST → ParsedInvite (typed METHOD / ATTENDEE / ORGANIZER / SEQUENCE / RRULE / …).
• vtimezone — Inline VTIMEZONE handling with chrono-tz IANA fallback.
• serialize — ParsedInvite → RFC 5545 text (for iTIP REPLY).

Top-level entry point parse_invite takes raw text/calendar bytes and returns a fully-typed ParsedInvite.

What this crate does NOT do

• No MIME parsing — extract the text/calendar part upstream (e.g. with mail-parser).
• No SMTP. See mailrs-smtp-proto / mailrs-smtp-client.
• No calendar storage or CalDAV. This is the wire-format layer only.

Modules

parse

RFC 5545 §3.1 text → AST.

semantics

AST → typed ParsedInvite.

serialize

ParsedInvite → RFC 5545 text.

vtimezone

Inline VTIMEZONE handling with chrono-tz fallback.

Structs

Attendee

One ATTENDEE row from a VEVENT.

ParsedInvite

Fully-typed iTIP invite, the boundary between this module and the rest of the server (MRS-3..MRS-9 all consume this).

Person

ORGANIZER or any other CAL-ADDRESS-shaped property.

RawComponent

Generic raw component captured by the AST parser before semantic typing.

RawProperty

Single iCalendar property with its value + parameters.

VTimezone

VTIMEZONE component (RFC 5545 §3.6.5).

Enums

CalDateTime

Calendar date-time tri-state (RFC 5545 §3.3.5).

EventStatus

STATUS property values for a VEVENT (RFC 5545 §3.8.1.11).

IcalError

Errors returned by parse_invite.

Method

iTIP method (RFC 5546 §1.4 + §3).

PartStat

PARTSTAT parameter (RFC 5545 §3.2.12).

Role

ROLE parameter (RFC 5545 §3.2.16).

Functions

parse_invite

Top-level entry: raw text/calendar bytes → fully-typed invite.