56 lines
1.3 KiB
Rust
56 lines
1.3 KiB
Rust
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use core::{fmt, ops::Deref};
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#[derive(Clone, Copy, PartialEq, Eq)]
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pub struct Span {
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pub start: u32,
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pub end: u32,
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}
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impl Span {
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pub fn new(start: u32, end: u32) -> Self {
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Self { start, end }
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}
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pub fn slice<'a>(&self, source: &'a SourceCode) -> &'a str {
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&source.code[self.start as usize..self.end as usize]
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}
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}
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impl fmt::Debug for Span {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(f, "{}..{}", self.start, self.end)
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}
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}
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/// Source code string with a verified size limit.
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/// An exact size limit is not enforced by this type - it only ensures the string isn't longer than
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/// intended, to not stall the parser for an unexpected amount of time.
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#[derive(Debug, PartialEq, Eq)]
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#[repr(transparent)]
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pub struct SourceCode {
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code: str,
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}
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impl SourceCode {
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pub fn limited_len(code: &str, max_len: u32) -> Option<&Self> {
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if code.len() <= max_len as usize {
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Some(Self::unlimited_len(code))
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} else {
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None
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}
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}
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pub fn unlimited_len(code: &str) -> &Self {
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// SAFETY: SourceCode is a transparent wrapper around str, so converting between them is safe.
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unsafe { core::mem::transmute(code) }
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}
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}
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impl Deref for SourceCode {
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type Target = str;
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fn deref(&self) -> &Self::Target {
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&self.code
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}
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}
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