Struct Span 

pub struct Span {
    pub start: usize,
    pub end: usize,
}

A half-open byte range into the source.

tatara-lisp’s Span, not a blue one. blue used to declare its own { start, end } pair here, which was a strict subset of the substrate’s: tatara’s carries the same two fields plus synthetic() / is_synthetic(), merge, line_col and a Display. Two structurally-identical span types in one pipeline is the duplication that forces a conversion at every boundary — and the boundary that mattered is the one where a checker diagnostic reaches the LSP, because a conversion that has to invent a value for “no span” is how a type error ends up reported at line 0.

Sharing the type also means the parser can emit tatara_lisp::Spanned directly: the tree blue parses into is the tree the evaluator eats, spans and all. A half-open byte range [start, end) into the source.

Fields

start: usize

end: usize

Implementations

impl Span

pub const fn new(start: usize, end: usize) -> Span

pub const fn synthetic() -> Span

A span for nodes produced by macro expansion that have no direct source origin. start == end == usize::MAX is the sentinel.

pub const fn is_synthetic(&self) -> bool

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

Merge two spans into the smallest span that covers both. If either is synthetic, returns the other; if both are synthetic, returns synthetic.

pub fn line_col(src: &str, byte_offset: usize) -> (usize, usize)

Resolve (line, column) for byte_offset in src (1-indexed). Used for human-readable error messages; O(n) in source length — not for hot paths.

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<(), Error>

Formats the value using the given formatter.

impl Display for Span

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

Formats the value using the given formatter.

impl Eq for Span

impl Hash for Span

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

where __H: Hasher,

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