Struct proc_macro2::Span
source · pub struct Span { /* private fields */ }
Expand description
A region of source code, along with macro expansion information.
Implementations§
source§impl Span
impl Span
sourcepub fn call_site() -> Self
pub fn call_site() -> Self
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.
sourcepub fn mixed_site() -> Self
pub fn mixed_site() -> Self
The span located at the invocation of the procedural macro, but with
local variables, labels, and $crate
resolved at the definition site
of the macro. This is the same hygiene behavior as macro_rules
.
sourcepub fn resolved_at(&self, other: Span) -> Span
pub fn resolved_at(&self, other: Span) -> Span
Creates a new span with the same line/column information as self
but
that resolves symbols as though it were at other
.
sourcepub fn located_at(&self, other: Span) -> Span
pub fn located_at(&self, other: Span) -> Span
Creates a new span with the same name resolution behavior as self
but
with the line/column information of other
.
sourcepub fn unwrap(self) -> Span
pub fn unwrap(self) -> Span
Convert proc_macro2::Span
to proc_macro::Span
.
This method is available when building with a nightly compiler, or when building with rustc 1.29+ without semver exempt features.
§Panics
Panics if called from outside of a procedural macro. Unlike
proc_macro2::Span
, the proc_macro::Span
type can only exist within
the context of a procedural macro invocation.
sourcepub fn join(&self, other: Span) -> Option<Span>
pub fn join(&self, other: Span) -> Option<Span>
Create a new span encompassing self
and other
.
Returns None
if self
and other
are from different files.
Warning: the underlying proc_macro::Span::join
method is
nightly-only. When called from within a procedural macro not using a
nightly compiler, this method will always return None
.
sourcepub fn source_text(&self) -> Option<String>
pub fn source_text(&self) -> Option<String>
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.
Trait Implementations§
impl Copy for Span
Auto Trait Implementations§
impl Freeze for Span
impl RefUnwindSafe for Span
impl !Send for Span
impl !Sync for Span
impl Unpin for Span
impl UnwindSafe for Span
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
T: Copy,
impl<T> CloneToUninit for Twhere
T: Copy,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)