Crate mail_chars

Provides char classification for mail related grammar parts/charset, i.e. if a given char belongs characters valid in atext, ctext, dtext, token etc.

The Charset enum is used to determine which set of character is used. To check if a char is in that set either use Charset::contains(&self, char) or use ch.is(charset) which is provided through the CharMatchExt extension trait.

Why Ws is merged into CText, DText and QText

Any grammar part in which qtext/ctext/dtext is used is in a form which 1. repeats 2. prepends FWS in the repeating part.

Which means any parser would have to parse for chars which are qtext/ctext/dtext OR ws (and special handling if it hits another character like "\r" indicating the start of a soft line break etc.).

For example wrt. dtext the grammar is ... *([FWS] dtext) [FWS] ... which you can validate by parsing chars which are either dtext or ws and if you hit a "\r" (which btw. is not in ws) you make sure it’s followed by "\n " or "\n\t" and then you continue with parsing.

Alternative interface

All enum variants are re-exported under a module with the name of the rfc where they are specified. E.g. Charset::CText is also available as rfc5322::CText.

Example

extern crate mail_chars;
use mail_chars::{Charset, rfc5322, rfc2045, CharMatchExt};

fn main() {
    assert!(Charset::AText.contains('d'));
    assert!('d'.is(Charset::AText));
    assert!('d'.is(rfc5322::AText));

    // `rfc*::*` are just reexports grouped by RFC.
    assert_eq!(Charset::Token, rfc2045::Token);

    // If we want to test for more than on char set we can use lookup.
    let res = Charset::lookup('.');
    // Has the benefit that there is a is_ascii method
    assert!(res.is_ascii());
    assert!(res.is(rfc2045::Token));
    assert!(res.is(rfc5322::CTextWs));
    assert!(!res.is(rfc5322::AText));
}

Modules

rfc2045

Re-export of all charsets (Charset::… variants) from rfc2045.

rfc5322

Re-export of all charsets (Charset::… variants) from rfc5322.

rfc6838

Re-export of all charsets (Charset::… variants) from rfc6838.

rfc7230

Re-export of all charsets (Charset::… variants) from rfc7320.

Structs

LookupResult

Represents the result of a lookup of a char.

Enums

Charset

An enum for the charsets represented through an internal lookup table.

Traits

CharMatchExt

Seal

Functions

is_vchar

is_ws