lib.rs

#[cfg(feature = "ast")]
pub mod ast;
pub mod lex;
#[cfg(feature = "transpiler")]
pub mod transpile;
use std::fmt;

pub use lex::Lexer;

/// Source code span
/// Useful to track the position of a text fragment in the source code, for error reporting.
///
/// ```
/// use cppshift::SourceSpan;
///
/// let src = "test";
/// let src_span = SourceSpan::new(src, 1, 2);
/// assert_eq!("es", src_span.src());
/// assert_eq!((1..3), core::ops::Range::<usize>::from(src_span));
/// ```
#[derive(Clone, Copy, PartialEq)]
pub struct SourceSpan<'de> {
    src: &'de str,
    offset: usize,
    len: usize,
}

impl<'de> SourceSpan<'de> {
    /// Create a new Span from an offset and a length
    pub fn new(src: &'de str, offset: usize, len: usize) -> SourceSpan<'de> {
        SourceSpan { src, offset, len }
    }

    /// Getter of the source code value
    pub fn src(&self) -> &'de str {
        &self.src[core::ops::Range::from(*self)]
    }

    /// Returns the full backing source string (not just this span's slice).
    pub fn full_source(&self) -> &'de str {
        self.src
    }
}

impl<'de> fmt::Debug for SourceSpan<'de> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("SourceSpan")
            .field("src", &self.src())
            .field("offset", &self.offset)
            .field("len", &self.len)
            .finish()
    }
}

impl<'de> From<SourceSpan<'de>> for miette::SourceSpan {
    fn from(span: SourceSpan<'de>) -> Self {
        miette::SourceSpan::new(span.offset.into(), span.len)
    }
}

impl<'de> From<SourceSpan<'de>> for core::ops::Range<usize> {
    fn from(span: SourceSpan<'de>) -> Self {
        core::ops::Range {
            start: span.offset,
            end: span.offset + span.len,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn source_span() {
        let src = "test";
        let src_span = SourceSpan::new(src, 1, 2);
        assert_eq!("es", src_span.src());
        assert_eq!((1..3), core::ops::Range::<usize>::from(src_span));
    }
}