Struct Span 

pub struct Span {
    pub file_id: FileId,
    pub start: u32,
    pub end: u32,
}

A span representing a range in the source code.

Spans use byte offsets into the source string and include a file identifier for multi-file compilation. They are designed to be small (12 bytes) and cheap to copy.

Fields

file_id: FileId

The file this span belongs to

start: u32

Start byte offset (inclusive)

end: u32

End byte offset (exclusive)

Implementations

impl Span

pub const fn new(start: u32, end: u32) -> Self

Create a new span from start and end byte offsets.

Uses the default file ID. For multi-file compilation, use with_file.

pub const fn with_file(file_id: FileId, start: u32, end: u32) -> Self

Create a new span with a specific file ID.

pub const fn point(pos: u32) -> Self

Create an empty span at a single position.

Uses the default file ID. For multi-file compilation, use point_in_file.

pub const fn point_in_file(file_id: FileId, pos: u32) -> Self

Create an empty span at a single position in a specific file.

pub const fn cover(a: Span, b: Span) -> Self

Create a span covering two spans (from start of first to end of second).

Uses the file ID from span a. Both spans should be from the same file.

pub const fn extend_to(&self, end: u32) -> Self

Extend this span to a new end position, preserving the file ID.

Creates a span from self.start to end with the same file ID.

pub const fn start(&self) -> u32

Get the start byte offset.

pub const fn len(&self) -> u32

The length of this span in bytes.

pub const fn is_empty(&self) -> bool

Whether this span is empty.

pub const fn contains(&self, other: Span) -> bool

Returns true if other is entirely contained within this span.

A span a contains span b if a.start <= b.start and b.end <= a.end. An empty span at a boundary is considered contained.

Example

use gruel_span::Span;

let outer = Span::new(5, 20);
let inner = Span::new(10, 15);
let overlapping = Span::new(15, 25);

assert!(outer.contains(inner));
assert!(!outer.contains(overlapping));
assert!(outer.contains(Span::point(10)));

pub const fn contains_pos(&self, pos: u32) -> bool

Returns true if this span contains the given byte position.

The position is contained if self.start <= pos < self.end. Note: the end position is exclusive, so pos == self.end returns false.

Example

use gruel_span::Span;

let span = Span::new(5, 10);
assert!(!span.contains_pos(4));  // before span
assert!(span.contains_pos(5));   // at start (inclusive)
assert!(span.contains_pos(7));   // in middle
assert!(!span.contains_pos(10)); // at end (exclusive)

pub const fn as_range(&self) -> Range<usize>

Convert to a Range for slicing.

pub fn line_number(&self, source: &str) -> usize

Compute the 1-based line number for this span’s start position.

Returns the line number (1-indexed) where this span begins.

Panics

In debug builds, panics if self.start exceeds source.len(). In release builds, out-of-bounds offsets are clamped to source.len().

pub fn line_col(&self, source: &str) -> (usize, usize)

Compute the 1-based line and column numbers for this span’s start position.

Returns (line, column) where both are 1-indexed. The column is the number of bytes from the start of the line, plus 1.

Panics

In debug builds, panics if self.start exceeds source.len(). In release builds, out-of-bounds offsets are clamped to source.len().

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Span

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

Formats the value using the given formatter.

impl Default for Span

fn default() -> Span

Returns the “default value” for a type.

impl From<Range<u32>> for Span

fn from(range: Range<u32>) -> Self

Converts to this type from the input type.

impl From<Range<usize>> for Span

fn from(range: Range<usize>) -> Self

Converts to this type from the input type.

impl Hash for Span

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Span

fn eq(&self, other: &Span) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Span

impl Eq for Span

impl StructuralPartialEq for Span