headers_core/
lib.rs

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1#![deny(missing_docs)]
2#![deny(missing_debug_implementations)]
3#![cfg_attr(test, deny(warnings))]
4#![doc(html_root_url = "https://docs.rs/headers-core/0.3.0")]
5
6//! # headers-core
7//!
8//! This is the core crate of the typed HTTP headers system, providing only
9//! the relevant traits. All actual header implementations are in other crates.
10
11extern crate http;
12
13pub use http::header::{self, HeaderName, HeaderValue};
14
15use std::error;
16use std::fmt::{self, Display, Formatter};
17
18/// A trait for any object that will represent a header field and value.
19///
20/// This trait represents the construction and identification of headers,
21/// and contains trait-object unsafe methods.
22pub trait Header {
23    /// The name of this header.
24    fn name() -> &'static HeaderName;
25
26    /// Decode this type from an iterator of `HeaderValue`s.
27    fn decode<'i, I>(values: &mut I) -> Result<Self, Error>
28    where
29        Self: Sized,
30        I: Iterator<Item = &'i HeaderValue>;
31
32    /// Encode this type to a `HeaderMap`.
33    ///
34    /// This function should be infallible. Any errors converting to a
35    /// `HeaderValue` should have been caught when parsing or constructing
36    /// this value.
37    fn encode<E: Extend<HeaderValue>>(&self, values: &mut E);
38}
39
40/// Errors trying to decode a header.
41#[derive(Debug)]
42pub struct Error {
43    kind: Kind,
44}
45
46#[derive(Debug)]
47enum Kind {
48    Invalid,
49}
50
51impl Error {
52    /// Create an 'invalid' Error.
53    pub fn invalid() -> Error {
54        Error {
55            kind: Kind::Invalid,
56        }
57    }
58}
59
60impl Display for Error {
61    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
62        match &self.kind {
63            Kind::Invalid => f.write_str("invalid HTTP header"),
64        }
65    }
66}
67
68impl error::Error for Error {}
headers_core/lib.rs

headers_core/
lib.rs
