der/tag/
mode.rs

1//! Tag modes.
2
3use crate::{Error, ErrorKind, Result};
4use core::{fmt, str::FromStr};
5
6/// Tagging modes: `EXPLICIT` versus `IMPLICIT`.
7#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
8pub enum TagMode {
9    /// `EXPLICIT` tagging.
10    ///
11    /// Tag is added in addition to the inner tag of the type.
12    #[default]
13    Explicit,
14
15    /// `IMPLICIT` tagging.
16    ///
17    /// Tag replaces the existing tag of the inner type.
18    Implicit,
19}
20
21impl FromStr for TagMode {
22    type Err = Error;
23
24    fn from_str(s: &str) -> Result<Self> {
25        match s {
26            "EXPLICIT" | "explicit" => Ok(TagMode::Explicit),
27            "IMPLICIT" | "implicit" => Ok(TagMode::Implicit),
28            _ => Err(ErrorKind::TagModeUnknown.into()),
29        }
30    }
31}
32
33impl fmt::Display for TagMode {
34    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
35        match self {
36            TagMode::Explicit => f.write_str("EXPLICIT"),
37            TagMode::Implicit => f.write_str("IMPLICIT"),
38        }
39    }
40}