Enum rustc_parse::parser::PathStyle

pub enum PathStyle {
    Expr,
    Pat,
    Type,
    Mod,
}

Specifies how to parse a path.

Variants

Expr

In some contexts, notably in expressions, paths with generic arguments are ambiguous with something else. For example, in expressions segment < .... can be interpreted as a comparison and segment ( .... can be interpreted as a function call. In all such contexts the non-path interpretation is preferred by default for practical reasons, but the path interpretation can be forced by the disambiguator ::, e.g. x<y> - comparisons, x::<y> - unambiguously a path.

Also, a path may never be followed by a :. This means that we can eagerly recover if we encounter it.

Pat

The same as Expr, but may be followed by a :. For example, this code:

struct S;

let S: S;
//  ^ Followed by a `:`

Type

In other contexts, notably in types, no ambiguity exists and paths can be written without the disambiguator, e.g., x<y> - unambiguously a path. Paths with disambiguators are still accepted, x::<Y> - unambiguously a path too.

Mod

A path with generic arguments disallowed, e.g., foo::bar::Baz, used in imports, visibilities or attributes. Technically, this variant is unnecessary and e.g., Expr can be used instead (paths in “mod” contexts have to be checked later for absence of generic arguments anyway, due to macros), but it is used to avoid weird suggestions about expected tokens when something goes wrong.

Implementations

impl PathStyle

fn has_generic_ambiguity(&self) -> bool

Trait Implementations

impl Clone for PathStyle

fn clone(&self) -> PathStyle

Returns a copy of the value.

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

Performs copy-assignment from source.

impl PartialEq<PathStyle> for PathStyle

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for PathStyle

impl StructuralPartialEq for PathStyle

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 1 byte

Size for each variant:

• Expr: 0 bytes
• Pat: 0 bytes
• Type: 0 bytes
• Mod: 0 bytes