Enum Error 

pub enum Error {
    Empty,
    MissingHeader(String),
    BadHeader(String),
    BadPath(String),
}

What can go wrong.

Four variants, arising from exactly two situations: a message with no usable header, and a path that is not a path. Everything else about ER7 is recoverable, and this crate recovers rather than refusing, because a receiver that rejects a message it could have read is worse than one that reads it as written (spec §11, rules R6 and R23).

Example:

use er7::Error;

assert!(matches!(er7::parse(""), Err(Error::Empty)));
assert!(matches!(er7::parse("PID|1"), Err(Error::MissingHeader(_))));
assert!(matches!(er7::parse("MSH"), Err(Error::BadHeader(_))));
assert!(matches!("PID-0".parse::<er7::Path>(), Err(Error::BadPath(_))));

// Everything below the header parses, however odd it is.
assert!(er7::parse("MSH|^~\\&|LAB\rZZZ\rPID||||||||||").is_ok());

Variants

Empty

The input held no segments at all — it was empty, or held only blank lines.

MissingHeader(String)

The first segment is not MSH, FHS, or BHS, so the message never declared its delimiters. Carries the segment name that was found instead.

BadHeader(String)

The header segment declared a delimiter set that cannot be used: missing, alphanumeric, a line ending, or reusing one character for two roles (spec §3.3). Carries a sentence naming the problem.

BadPath(String)

A path such as PID-5.1 could not be read (spec §8.1). Carries the path and the reason.

Trait Implementations

impl Clone for Error

fn clone(&self) -> Error

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

One complete sentence, with no trailing period and no error prefix, so it reads correctly whether a caller writes {e}, wraps it, or prefixes it as the CLI does.

impl Eq for Error

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for Error

fn eq(&self, other: &Error) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Error