HL7v2 message parsing in Rust.

Parses the structure of HL7v2 messages, but does not validate the correctness of the messages.

Examples

Parsing a Message

use hl7_parser::Message;
use std::num::NonZeroUsize;

let message = r#"
MSH|^~\&|AccMgr|1|||20050110045504||ADT^A01|599102|P|2.3|||
PID|1||10006579^^^1^MRN^1||DUCK^DONALD^D||19241010|M||1|111 DUCK ST^^FOWL^CA^999990000^^M|1|8885551212|8885551212|1|2||40007716^^^AccMgr^VN^1|123121234|||||||||||NO NK1|1|DUCK^HUEY|SO|3583 DUCK RD^^FOWL^CA^999990000|8885552222||Y||||||||||||||
PV1|1|I|PREOP^101^1^1^^^S|3|||37^DISNEY^WALT^^^^^^AccMgr^^^^CI|||01||||1|||37^DISNEY^WALT^^^^^^AccMgr^^^^CI|2|40007716^^^AccMgr^VN|4|||||||||||||||||||1||G|||20050110045253||||||
"#.replace("\r\n", "\r").replace('\n', "\r");

let message = Message::parse(message.trim()).expect("can parse message");
let message_type = message.get_field_source(("MSH", 0), NonZeroUsize::new(9).unwrap());
assert_eq!(message_type.unwrap(), "ADT^A01");

Querying a Message

use hl7_parser::Message;

let message = include_str!("../test_assets/sample_adt_a01.hl7")
    .replace("\r\n", "\r")
    .replace('\n', "\r");
let message = Message::parse(&message).expect("can parse message");

let trigger_event = message.query_value("MSH.9.2").expect("can parse location query");
assert_eq!(trigger_event, Some("A01"));

Locating the Cursor Within A Message

(The cursor being the character index of some point within the buffer)

use hl7_parser::Message;
use std::num::NonZeroUsize;

let message = r#"
MSH|^~\&|AccMgr|1|||20050110045504||ADT^A01|599102|P|2.3|||
PID|1||10006579^^^1^MRN^1||DUCK^DONALD^D||19241010|M||1|111 DUCK ST^^FOWL^CA^999990000^^M|1|8885551212|8885551212|1|2||40007716^^^AccMgr^VN^1|123121234|||||||||||NO NK1|1|DUCK^HUEY|SO|3583 DUCK RD^^FOWL^CA^999990000|8885552222||Y||||||||||||||
PV1|1|I|PREOP^101^1^1^^^S|3|||37^DISNEY^WALT^^^^^^AccMgr^^^^CI|||01||||1|||37^DISNEY^WALT^^^^^^AccMgr^^^^CI|2|40007716^^^AccMgr^VN|4|||||||||||||||||||1||G|||20050110045253||||||
"#.replace("\r\n", "\r").replace('\n', "\r");

let message = Message::parse(message.trim()).expect("can parse message");
let location = message.locate_cursor(25);
assert_eq!(location.segment.unwrap().0, "MSH");
assert_eq!(location.field.unwrap().0.get(), 7);
assert_eq!(location.field.unwrap().1.source(message.source), "20050110045504");

Parsing Message Timestamps

use hl7_parser::parse_time;

let ts = "20230312195905-0700";
let ts = parse_time(ts).expect("can parse timestamp");

assert_eq!(ts.year(), 2023);
assert_eq!(ts.month(), time::Month::March);
assert_eq!(ts.day(), 12);
assert_eq!(ts.hour(), 19);
assert_eq!(ts.minute(), 59);
assert_eq!(ts.second(), 05);
assert_eq!(ts.microsecond(), 0);
assert_eq!(ts.offset().whole_hours(), -7);
assert_eq!(ts.offset().minutes_past_hour(), 0);

Decoding Encoded Strings

use hl7_parser::Separators;

let separators = Separators::default();
assert_eq!(
    separators.decode(r#"Pierre DuRho\S\ne \T\ Cie"#).as_str(),
    r#"Pierre DuRho^ne & Cie"#
);