Struct proc_macro::Span

1.29.0 · source · [−]

pub struct Span(_);

Expand description

A region of source code, along with macro expansion information.

Implementations

impl Span

source

pub fn def_site() -> Span

source

🔬 This is a nightly-only experimental API. (proc_macro_def_site #54724)

A span that resolves at the macro definition site.

pub fn call_site() -> Span

source

The span of the invocation of the current procedural macro. Identifiers created with this span will be resolved as if they were written directly at the macro call location (call-site hygiene) and other code at the macro call site will be able to refer to them as well.

pub fn mixed_site() -> Span

1.45.0 · source

A span that represents macro_rules hygiene, and sometimes resolves at the macro definition site (local variables, labels, $crate) and sometimes at the macro call site (everything else). The span location is taken from the call-site.

pub fn source_file(&self) -> SourceFile

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

The original source file into which this span points.

pub fn parent(&self) -> Option

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

The Span for the tokens in the previous macro expansion from which self was generated from, if any.

pub fn source(&self) -> Span

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

The span for the origin source code that self was generated from. If this Span wasn’t generated from other macro expansions then the return value is the same as *self.

pub fn start(&self) -> LineColumn

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

Gets the starting line/column in the source file for this span.

pub fn end(&self) -> LineColumn

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

Gets the ending line/column in the source file for this span.

pub fn before(&self) -> Span

source

🔬 This is a nightly-only experimental API. (proc_macro_span_shrink #87552)

Creates an empty span pointing to directly before this span.

pub fn after(&self) -> Span

source

🔬 This is a nightly-only experimental API. (proc_macro_span_shrink #87552)

Creates an empty span pointing to directly after this span.

pub fn join(&self, other: Span) -> Option

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

Creates a new span encompassing self and other.

Returns None if self and other are from different files.

pub fn resolved_at(&self, other: Span) -> Span

1.45.0 · source

Creates a new span with the same line/column information as self but that resolves symbols as though it were at other.

pub fn located_at(&self, other: Span) -> Span

1.45.0 · source

Creates a new span with the same name resolution behavior as self but with the line/column information of other.

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

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

Compares to spans to see if they’re equal.

pub fn source_text(&self) -> Option<String>

source

🔬 This is a nightly-only experimental API. (proc_macro_span #54725)

Returns the source text behind a span. This preserves the original source code, including spaces and comments. It only returns a result if the span corresponds to real source code.

Note: The observable result of a macro should only rely on the tokens and not on this source text. The result of this function is a best effort to be used for diagnostics only.