cedar_policy_core/parser/
loc.rs

1/*
2 * Copyright Cedar Contributors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17use serde::{Deserialize, Serialize};
18use std::sync::Arc;
19
20/// Represents a source location: index/range, and a reference to the source
21/// code which that index/range indexes into
22#[derive(Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, PartialOrd, Ord)]
23pub struct Loc {
24    /// `SourceSpan` indicating a specific source code location or range
25    pub span: miette::SourceSpan,
26
27    /// Original source code (which the above source span indexes into)
28    pub src: Arc<str>,
29}
30
31impl Loc {
32    /// Create a new `Loc`
33    pub fn new(span: impl Into<miette::SourceSpan>, src: Arc<str>) -> Self {
34        Self {
35            span: span.into(),
36            src,
37        }
38    }
39
40    /// Create a new `Loc` with the same source code but a different span
41    pub fn span(&self, span: impl Into<miette::SourceSpan>) -> Self {
42        Self {
43            span: span.into(),
44            src: Arc::clone(&self.src),
45        }
46    }
47
48    /// Get the index representing the start of the source span
49    pub fn start(&self) -> usize {
50        self.span.offset()
51    }
52
53    /// Get the index representing the end of the source span
54    pub fn end(&self) -> usize {
55        self.span.offset() + self.span.len()
56    }
57
58    /// Get the actual source snippet indicated, or `None` if the `Loc` isn't
59    /// internally consistent (its `SourceSpan` isn't a valid index into its
60    /// `src`)
61    pub fn snippet(&self) -> Option<&str> {
62        self.src.get(self.start()..self.end())
63    }
64}
65
66impl From<Loc> for miette::SourceSpan {
67    fn from(loc: Loc) -> Self {
68        loc.span
69    }
70}
71
72impl From<&Loc> for miette::SourceSpan {
73    fn from(loc: &Loc) -> Self {
74        loc.span
75    }
76}
77
78impl miette::SourceCode for Loc {
79    fn read_span<'a>(
80        &'a self,
81        span: &miette::SourceSpan,
82        context_lines_before: usize,
83        context_lines_after: usize,
84    ) -> Result<Box<dyn miette::SpanContents<'a> + 'a>, miette::MietteError> {
85        self.src
86            .read_span(span, context_lines_before, context_lines_after)
87    }
88}
89
90impl miette::SourceCode for &Loc {
91    fn read_span<'a>(
92        &'a self,
93        span: &miette::SourceSpan,
94        context_lines_before: usize,
95        context_lines_after: usize,
96    ) -> Result<Box<dyn miette::SpanContents<'a> + 'a>, miette::MietteError> {
97        self.src
98            .read_span(span, context_lines_before, context_lines_after)
99    }
100}
cedar_policy_core/parser/loc.rs

cedar_policy_core/parser/
loc.rs
