Struct SourceSpan

Source

pub struct SourceSpan {
    pub start: LineColumn,
    pub end: LineColumn,
}

Expand description

Source region as start/end line and column.

Uses proc_macro2::LineColumn for positions (1-based line, 0-based column). This type is Send + Sync. Build it from a proc_macro2::Span via SourceSpan::from_proc_macro2 when you have one (e.g. in the parser).

Fields§

§start: LineColumn

Start position (inclusive).

§end: LineColumn

End position (exclusive; one past the last character, matching proc_macro2::Span::end()).

Implementations§

Source §

impl SourceSpan

Source

pub fn new( start_line: usize, start_column: usize, end_line: usize, end_column: usize, ) -> Self

Builds a span from raw line/column values.

Lines are 1-based, columns are 0-based (matching proc_macro2::LineColumn).

§Examples

use cel_parser::SourceSpan;

let span = SourceSpan::new(1, 0, 1, 5);
assert_eq!(span.start.line, 1);
assert_eq!(span.end.column, 5);

Source

pub fn from_proc_macro2(span: Span) -> Self

Extracts start/end line and column from a proc_macro2::Span.

Use this when creating errors in the parser or other code that has a proc_macro2::Span; the result is Send + Sync and can be stored in CELError for use from async or other threads.

§Examples

use proc_macro2::Span;
use cel_parser::SourceSpan;

let span = SourceSpan::from_proc_macro2(Span::call_site());
assert_eq!(span.start.line, span.end.line);

Source

pub fn from_proc_macro2_range(start: Span, end: Span) -> Self

Builds a span from two proc_macro2::Span values (start of start, end of end).

Use this when an expression spans multiple tokens and you want a range span.

§Examples

use proc_macro2::Span;
use cel_parser::SourceSpan;

let start = Span::call_site();
let end = Span::call_site();
let span = SourceSpan::from_proc_macro2_range(start, end);
assert_eq!(span.start.line, span.end.line);

Source

pub fn to_byte_range(&self, source: &str) -> Range<usize> ⓘ

Converts this span (1-based lines, 0-based character columns) to a byte-offset range within source.

Precondition: source is the exact original text this span’s line/column positions were recorded against.
Precondition: self.start.line >= 1 (spans use 1-based line numbers).
Precondition: self.end does not precede self.start (self.end.line > self.start.line, or they’re equal and self.end.column >= self.start.column).
Complexity: O(n) in the length of source.

§Examples

use cel_parser::SourceSpan;

let span = SourceSpan::new(1, 0, 1, 5);
let range = span.to_byte_range("hello world");
assert_eq!(&"hello world"[range], "hello");