Struct parsel::Span

source · 
pub struct Span { /* private fields */ }
Expand description

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

Implementations

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.

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.

This function requires Rust 1.45 or later.

A span that resolves at the macro definition site.

This method is semver exempt and not exposed by default.

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

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

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.

The original source file into which this span points.

This method is semver exempt and not exposed by default.

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

This method requires the "span-locations" feature to be enabled.

When executing in a procedural macro context, the returned line/column are only meaningful if compiled with a nightly toolchain. The stable toolchain does not have this information available. When executing outside of a procedural macro, such as main.rs or build.rs, the line/column are always meaningful regardless of toolchain.

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

This method requires the "span-locations" feature to be enabled.

When executing in a procedural macro context, the returned line/column are only meaningful if compiled with a nightly toolchain. The stable toolchain does not have this information available. When executing outside of a procedural macro, such as main.rs or build.rs, the line/column are always meaningful regardless of toolchain.

Creates an empty span pointing to directly before this span.

This method is semver exempt and not exposed by default.

Creates an empty span pointing to directly after this span.

This method is semver exempt and not exposed by default.

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.

Compares two spans to see if they’re equal.

This method is semver exempt and not exposed by default.

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more

Prints a span in a form convenient for debugging.

Formats the value using the given formatter. Read more
Converts to this type from the input type.
Converts to this type from the input type.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Returns a Span covering the complete contents of this syntax tree node, or Span::call_site() if this node is empty. Read more

TODO(H2CO3): a faster, less naive implementation would be great. We should use the byte offset of start to compute that of end, sparing the double scan of the source up until the start location.

let source = r#"
   -3.667
  1248  "string ű literal"
      "wíőzs"
"#;
let tokens: Many<Lit> = source.parse()?;

assert_eq!(tokens.len(), 4);
assert_eq!(tokens[0].byte_range(source),  4..10);
assert_eq!(tokens[1].byte_range(source), 13..17);
assert_eq!(tokens[2].byte_range(source), 19..38);
assert_eq!(tokens[3].byte_range(source), 45..54);

TODO(H2CO3): a faster, less naive implementation would be great. We should use the char offset of start to compute that of end, sparing the double scan of the source up until the start location.

let source = r#"
   -3.667
  1248  "string ű literal"
      "wíőzs"
"#;
let tokens: Many<Lit> = source.parse()?;

assert_eq!(tokens.len(), 4);
assert_eq!(tokens[0].char_range(source),  4..10);
assert_eq!(tokens[1].char_range(source), 13..17);
assert_eq!(tokens[2].char_range(source), 19..37);
assert_eq!(tokens[3].char_range(source), 44..51);
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.