Struct CroppedRegion 

#[non_exhaustive]
pub struct CroppedRegion<'a> {
    pub lines: Vec<&'a str>,
    pub focus_index: usize,
    pub low_line: usize,
    pub focus_line: usize,
}

A windowed slice of source text around an error location.

Used internally by Error::render_with_options and exposed for callers that want to extract the snippet without formatting it themselves.

Examples

use noyalib::CroppedRegion;
let src = "line 1\nline 2 — error here\nline 3\nline 4\n";
let region = CroppedRegion::extract(src, 2, 1);
assert_eq!(region.lines.len(), 3);
assert!(region.lines[1].contains("error"));

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

lines: Vec<&'a str>

The lines extracted from the source — indices low_line..=high_line.

focus_index: usize

0-based index in lines of the offending line (i.e., the line corresponding to the original target_line parameter).

low_line: usize

The 1-based line number of the first line in lines.

focus_line: usize

The 1-based line number of the offending (focus) line.

Implementations

impl<'a> CroppedRegion<'a>

pub fn extract( source: &'a str, target_line: usize, radius: usize, ) -> CroppedRegion<'a>

Extract a radius-line window around target_line (1-based) from source. Out-of-range targets clamp to the available lines; an empty source yields an empty region with focus_line = 0.

Examples

use noyalib::CroppedRegion;
let src = "a\nb\nc\nd\ne\n";
let r = CroppedRegion::extract(src, 3, 1);
assert_eq!(r.lines, vec!["b", "c", "d"]);
assert_eq!(r.focus_index, 1);
assert_eq!(r.focus_line, 3);

Trait Implementations

impl<'a> Clone for CroppedRegion<'a>

fn clone(&self) -> CroppedRegion<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for CroppedRegion<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Eq for CroppedRegion<'a>

impl<'a> PartialEq for CroppedRegion<'a>

fn eq(&self, other: &CroppedRegion<'a>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a> StructuralPartialEq for CroppedRegion<'a>