eml_codec/
header.rs

1use nom::{
2    branch::alt,
3    bytes::complete::{tag, take_while1},
4    character::complete::space0,
5    combinator::{into, recognize},
6    multi::many0,
7    sequence::{pair, terminated, tuple},
8    IResult,
9};
10use std::fmt;
11
12use crate::text::misc_token::unstructured;
13use crate::text::whitespace::{foldable_line, obs_crlf};
14
15#[derive(PartialEq, Clone)]
16pub struct Kv2<'a>(pub &'a [u8], pub &'a [u8]);
17impl<'a> From<(&'a [u8], &'a [u8])> for Kv2<'a> {
18    fn from(pair: (&'a [u8], &'a [u8])) -> Self {
19        Self(pair.0, pair.1)
20    }
21}
22impl<'a> fmt::Debug for Kv2<'a> {
23    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
24        fmt.debug_tuple("header::Kv2")
25            .field(&String::from_utf8_lossy(self.0))
26            .field(&String::from_utf8_lossy(self.1))
27            .finish()
28    }
29}
30
31#[derive(Debug, PartialEq, Clone)]
32pub enum Field<'a> {
33    Good(Kv2<'a>),
34    Bad(&'a [u8]),
35}
36impl<'a> From<Kv2<'a>> for Field<'a> {
37    fn from(kv: Kv2<'a>) -> Self {
38        Self::Good(kv)
39    }
40}
41impl<'a> From<&'a [u8]> for Field<'a> {
42    fn from(bad: &'a [u8]) -> Self {
43        Self::Bad(bad)
44    }
45}
46
47/// Parse headers as key/values
48pub fn header_kv(input: &[u8]) -> IResult<&[u8], Vec<Field>> {
49    terminated(
50        many0(alt((into(correct_field), into(foldable_line)))),
51        obs_crlf,
52    )(input)
53}
54
55pub fn field_any(input: &[u8]) -> IResult<&[u8], &[u8]> {
56    terminated(
57        take_while1(|c| (0x21..=0x7E).contains(&c) && c != 0x3A),
58        tuple((space0, tag(b":"), space0)),
59    )(input)
60}
61
62/// Optional field
63///
64/// ```abnf
65/// field      =   field-name ":" unstructured CRLF
66/// field-name =   1*ftext
67/// ftext      =   %d33-57 /          ; Printable US-ASCII
68///                %d59-126           ;  characters not including
69///                                   ;  ":".
70/// ```
71pub fn correct_field(input: &[u8]) -> IResult<&[u8], Kv2> {
72    terminated(into(pair(field_any, recognize(unstructured))), obs_crlf)(input)
73}
eml_codec/header.rs

eml_codec/
header.rs
