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zrx_id/id/filter/
terms.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//! Iterator over terms.
27
28use slab::Iter;
29
30use crate::id::expression::Term;
31
32use super::condition::Condition;
33use super::Filter;
34
35// ----------------------------------------------------------------------------
36// Structs
37// ----------------------------------------------------------------------------
38
39/// Iterator over terms.
40pub struct Terms<'a> {
41    /// Condition set, built from expressions.
42    conditions: Iter<'a, Condition>,
43    /// Current set of extracted terms.
44    inner: &'a [Term],
45}
46
47// ----------------------------------------------------------------------------
48// Implementations
49// ----------------------------------------------------------------------------
50
51impl Filter {
52    /// Creates an iterator over the terms.
53    ///
54    /// # Examples
55    ///
56    /// ```
57    /// # use std::error::Error;
58    /// # fn main() -> Result<(), Box<dyn Error>> {
59    /// use zrx_id::{selector, Expression, Filter};
60    ///
61    /// // Create filter builder and insert expression
62    /// let mut builder = Filter::builder();
63    /// builder.insert(Expression::any(|expr| {
64    ///     expr.with(selector!(location = "**/*.jpg")?)?
65    ///         .with(selector!(location = "**/*.png")?)
66    /// })?);
67    ///
68    /// // Create filter from builder
69    /// let filter = builder.build()?;
70    ///
71    /// // Create iterator over terms
72    /// for term in filter.terms() {
73    ///     println!("{term:?}");
74    /// }
75    /// # Ok(())
76    /// # }
77    /// ```
78    #[inline]
79    #[must_use]
80    pub fn terms(&self) -> Terms<'_> {
81        Terms {
82            conditions: self.conditions.iter(),
83            inner: &[],
84        }
85    }
86}
87
88// ----------------------------------------------------------------------------
89// Trait implementations
90// ----------------------------------------------------------------------------
91
92impl<'a> Iterator for Terms<'a> {
93    type Item = &'a Term;
94
95    /// Returns the next term.
96    fn next(&mut self) -> Option<Self::Item> {
97        loop {
98            // Check if we have terms left in the current condition
99            if let Some(term) = self.inner.first() {
100                self.inner = &self.inner[1..];
101                return Some(term);
102            }
103
104            // Fetch next condition and extract its terms
105            let (_, condition) = self.conditions.next()?;
106            self.inner = condition.terms();
107        }
108    }
109}