Struct Span 

pub struct Span { /* private fields */ }

A half-open byte range [start, end) within one file.

Internally stored as start plus len, so the only constructor Span::new can reject inversion at construction time and the invariant is preserved by construction thereafter. An empty span (len == 0) is valid and marks a position rather than a range.

Implementations

impl Span

pub const EMPTY: Span

An empty span at the very start of a file. A sensible default.

pub fn new(start: impl Into<BytePos>, end: impl Into<BytePos>) -> Span

The only public constructor. end must be >= start.

Panics (debug only) if end < start. In release builds an inverted range collapses to an empty span at start, so the type invariant is never violated even if a caller bypasses the debug assertion.

pub fn at(pos: impl Into<BytePos>) -> Span

An empty span anchored at a single offset. Useful for “at this position”.

pub const fn start(self) -> BytePos

pub const fn end(self) -> BytePos

pub const fn len(self) -> u32

pub const fn is_empty(self) -> bool

pub const fn shifted(self, delta: u32) -> Span

The same span, moved delta bytes later in the file.

The length is preserved, so the invariant holds by construction. Used to rebase spans produced against a fragment onto the file that contains it: the input-parser’s template scanner works in offsets relative to a backtick template’s interior, and the HIR bridge rebases the tree by the token’s start.

pub fn contains(self, pos: BytePos) -> bool

True if pos lies within [start, end).

pub fn cover(self, other: Span) -> Span

The smallest span covering both self and other. If the two spans are in different files the caller must use FileSpan::union instead.

An empty span acts as a neutral element: unioning with one returns the other span unchanged.

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 Copy for Span

impl Debug for Span

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

Formats the value using the given formatter.

impl Eq for Span

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Span