zrx_id/id/specificity/segment/
atom.rs

1// Copyright (c) 2025-2026 Zensical and contributors
2
3// SPDX-License-Identifier: MIT
4// All contributions are certified under the DCO
5
6// Permission is hereby granted, free of charge, to any person obtaining a copy
7// of this software and associated documentation files (the `Software`), to
8// deal in the Software without restriction, including without limitation the
9// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10// sell copies of the Software, and to permit persons to whom the Software is
11// furnished to do so, subject to the following conditions:
12
13// The above copyright notice and this permission notice shall be included in
14// all copies or substantial portions of the Software.
15
16// THE SOFTWARE IS PROVIDED `AS IS`, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18// FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
19// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22// IN THE SOFTWARE.
23
24// ----------------------------------------------------------------------------
25
26//! Atom.
27
28use std::fmt::{self, Display, Write};
29
30use super::set::Segments;
31
32mod character;
33mod wildcard;
34
35pub use character::Character;
36pub use wildcard::Wildcard;
37
38// ----------------------------------------------------------------------------
39// Enums
40// ----------------------------------------------------------------------------
41
42/// Atom.
43///
44/// Atoms are the basic building blocks of [`Segments`], representing literals,
45/// wildcards, character classes and groups of alternatives. Each [`Segment`][]
46/// contains a set of atoms that define which [`Specificity`][] the segment has,
47/// where specificity is determined by the least specific atom in the segment.
48///
49/// [`Segment`]: crate::id::specificity::segment::Segment
50/// [`Specificity`]: crate::id::specificity::Specificity
51#[derive(Clone, Debug, PartialEq, Eq)]
52pub enum Atom<'a> {
53    /// Literal, e.g., `main.rs`
54    Literal(&'a str),
55    /// Wildcard, i.e., `?`, `*`, or `**`.
56    Wildcard(Wildcard),
57    /// Character class, e.g., `[xyz]`.
58    Character(Character<'a>),
59    /// Alternate group, e.g., `{*.rs,*.md}`.
60    Group(Vec<Segments<'a>>),
61}
62
63// ----------------------------------------------------------------------------
64// Trait implementations
65// ----------------------------------------------------------------------------
66
67impl Display for Atom<'_> {
68    /// Formats the atom for display.
69    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
70        match self {
71            Atom::Literal(literal) => Display::fmt(literal, f),
72            Atom::Wildcard(wildcard) => Display::fmt(wildcard, f),
73            Atom::Character(character) => Display::fmt(character, f),
74            Atom::Group(group) => {
75                f.write_char('{')?;
76                for (i, segments) in group.iter().enumerate() {
77                    Display::fmt(&segments, f)?;
78
79                    // Write comma if not last
80                    if i < group.len() - 1 {
81                        f.write_char(',')?;
82                    }
83                }
84                f.write_char('}')
85            }
86        }
87    }
88}
zrx_id/id/specificity/segment/atom.rs

zrx_id/id/specificity/segment/
atom.rs
