Struct MetaItemParser

pub struct MetaItemParser<'a> {
    path: PathParser<'a>,
    args: ArgParser<'a>,
}

Utility that deconstructs a MetaItem into usable parts.

MetaItems are syntactically extremely flexible, but specific attributes want to parse them in custom, more restricted ways. This can be done using this struct.

MetaItems consist of some path, and some args. The args could be empty. In other words:

• name -> args are empty
• name(...) -> args are a list, which is the bit between the parentheses
• name = value-> arg is name_value, where the argument is the = value part

The syntax of MetaItems can be found at https://doc.rust-lang.org/reference/attributes.html

Fields

path: PathParser<'a>

args: ArgParser<'a>

Implementations

impl<'a> MetaItemParser<'a>

pub fn from_attr(attr: &'a NormalAttr, dcx: DiagCtxtHandle<'a>) -> Self

Create a new parser from a NormalAttr, which is stored inside of any ast::Attribute

impl<'a> MetaItemParser<'a>

pub fn span(&self) -> Span

pub fn path_without_args(&self) -> PathParser<'a>

Gets just the path, without the args.

pub fn args(&self) -> &ArgParser<'a>

Gets just the args parser, without caring about the path.

pub fn deconstruct(&self) -> (PathParser<'a>, &ArgParser<'a>)

pub fn path(&self) -> (PathParser<'a>, &ArgParser<'a>)

Asserts that this MetaItem starts with a path. Some examples:

• #[rustfmt::skip]: rustfmt::skip is a path
• #[allow(clippy::complexity)]: clippy::complexity is a path
• #[inline]: inline is a single segment path

pub fn word_without_args(&self) -> Option<Ident>

Asserts that this MetaItem starts with a word, or single segment path. Doesn’t return the args parser.

For examples. see Self::word

pub fn word_or_empty_without_args(&self) -> Ident

Like word, but returns an empty symbol instead of None

pub fn word(&self) -> Option<(Ident, &ArgParser<'a>)>

Asserts that this MetaItem starts with a word, or single segment path.

Some examples:

• #[inline]: inline is a word
• #[rustfmt::skip]: rustfmt::skip is a path, and not a word and should instead be parsed using path

pub fn word_or_empty(&self) -> (Ident, &ArgParser<'a>)

Like word, but returns an empty symbol instead of None

pub fn word_is(&self, sym: Symbol) -> Option<&ArgParser<'a>>

Asserts that this MetaItem starts with some specific word.

See word for examples of what a word is.

pub fn path_is(&self, segments: &[Symbol]) -> Option<&ArgParser<'a>>

Asserts that this MetaItem starts with some specific path.

See word for examples of what a word is.

Trait Implementations

impl<'a> Clone for MetaItemParser<'a>

fn clone(&self) -> MetaItemParser<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for MetaItemParser<'a>

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

Formats the value using the given formatter.

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: 80 bytes