rustledger_parser/
span.rs

1//! Source location tracking.
2
3use serde::{Deserialize, Serialize};
4use std::fmt;
5use std::ops::Range;
6
7/// A span in the source code, represented as a byte range.
8#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
9#[cfg_attr(
10    feature = "rkyv",
11    derive(rkyv::Archive, rkyv::Serialize, rkyv::Deserialize)
12)]
13pub struct Span {
14    /// Start byte offset (inclusive).
15    pub start: usize,
16    /// End byte offset (exclusive).
17    pub end: usize,
18}
19
20impl Span {
21    /// Create a new span.
22    #[must_use]
23    pub const fn new(start: usize, end: usize) -> Self {
24        Self { start, end }
25    }
26
27    /// Create a span from a range.
28    #[must_use]
29    pub const fn from_range(range: Range<usize>) -> Self {
30        Self {
31            start: range.start,
32            end: range.end,
33        }
34    }
35
36    /// Get the length of this span in bytes.
37    #[must_use]
38    pub const fn len(&self) -> usize {
39        self.end - self.start
40    }
41
42    /// Check if the span is empty.
43    #[must_use]
44    pub const fn is_empty(&self) -> bool {
45        self.start == self.end
46    }
47
48    /// Merge this span with another, returning a span that covers both.
49    #[must_use]
50    pub fn merge(&self, other: &Self) -> Self {
51        Self {
52            start: self.start.min(other.start),
53            end: self.end.max(other.end),
54        }
55    }
56
57    /// Get the source text for this span.
58    #[must_use]
59    pub fn text<'a>(&self, source: &'a str) -> &'a str {
60        &source[self.start..self.end]
61    }
62
63    /// Convert to a chumsky span.
64    #[must_use]
65    pub const fn into_range(self) -> Range<usize> {
66        self.start..self.end
67    }
68}
69
70impl From<Range<usize>> for Span {
71    fn from(range: Range<usize>) -> Self {
72        Self::from_range(range)
73    }
74}
75
76impl From<Span> for Range<usize> {
77    fn from(span: Span) -> Self {
78        span.start..span.end
79    }
80}
81
82impl fmt::Display for Span {
83    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
84        write!(f, "{}..{}", self.start, self.end)
85    }
86}
87
88/// A value with an associated source span.
89#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
90#[cfg_attr(
91    feature = "rkyv",
92    derive(rkyv::Archive, rkyv::Serialize, rkyv::Deserialize)
93)]
94pub struct Spanned<T> {
95    /// The value.
96    pub value: T,
97    /// The source span.
98    pub span: Span,
99}
100
101impl<T> Spanned<T> {
102    /// Create a new spanned value.
103    #[must_use]
104    pub const fn new(value: T, span: Span) -> Self {
105        Self { value, span }
106    }
107
108    /// Map the inner value.
109    #[must_use]
110    pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Spanned<U> {
111        Spanned {
112            value: f(self.value),
113            span: self.span,
114        }
115    }
116
117    /// Get a reference to the inner value.
118    #[must_use]
119    pub const fn inner(&self) -> &T {
120        &self.value
121    }
122
123    /// Unwrap the spanned value, discarding the span.
124    #[must_use]
125    pub fn into_inner(self) -> T {
126        self.value
127    }
128}
129
130impl<T: fmt::Display> fmt::Display for Spanned<T> {
131    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
132        write!(f, "{}", self.value)
133    }
134}
rustledger_parser/span.rs

rustledger_parser/
span.rs
