Enum CaptureError 

pub enum CaptureError {
    Unbounded {
        bound: CaptureBound,
    },
    Unread {
        cause: LiteralReadCause,
        path: TokenPath,
        at: SpanHandle,
    },
}

How reading one declared input into a captured surface refuses.

Two rows, because the two are facts about different things — and the difference is where each is reported.

Variants

Unbounded

The read ran past one of the declared magnitudes.

Fields

bound: CaptureBound

Which magnitude.

Unread

One literal’s spelling could not be read into the value it names, with declaration identity and producer placement retained separately.

Fields

cause: LiteralReadCause

Why it could not be read.

path: TokenPath

Which token of the declared input could not be read.

at: SpanHandle

The producer-local handle already bound to the token’s compiler span.

Implementations

impl CaptureError

pub fn canonical_bytes(&self) -> Vec<u8>

This refusal’s complete canonical material: which row it is, the stable name of what stopped the read, and — for a refusal about one token — that token’s declaration-local path.

The row’s position leads, so two rows whose names happened to coincide still derive two related identities. The producer-local span handle is excluded: captures of one declaration may issue different handles when they share a span table, while their declaration-local paths remain one fact.

impl CaptureError

pub fn placed(self, spans: &Spans) -> TokenStream

The compile_error! this refusal expands to, at the position it is a fact about.

A magnitude is a fact about the whole declaration and no one token overran it, so it is reported at the invocation. A literal this crate could not read is a fact about exactly one token, and that token’s handle was issued before its payload was read — so the span is held and the report goes there.

Nonclaims

It is not a Diagnostic: composing one needs the door whose prefix, grammar, and callable entry the line carries, and a capture runs before any door is named.

impl CaptureError

pub const fn slot(&self) -> u8

This row’s position in the declared roster, written ahead of the material it carries.

Appended and never renumbered: the byte stands inside every related identity derived over a refused capture.

Trait Implementations

impl Clone for CaptureError

fn clone(&self) -> CaptureError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CaptureError

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

Formats the value using the given formatter.

impl Display for CaptureError

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

Formats the value using the given formatter.

impl Eq for CaptureError

impl Error for CaptureError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<CaptureBound> for CaptureError

fn from(bound: CaptureBound) -> Self

Converts to this type from the input type.

impl Hash for CaptureError

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 CaptureError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for CaptureError