Struct Scope

pub struct Scope {
    pub attrs: Vec<Attribute>,
    pub vis: Visibility,
    pub ident: Ident,
    pub generics: Generics,
    pub item: ScopeItem,
    pub semi: Option<Semi>,
    pub impls: Vec<ItemImpl>,
    pub generated: Vec<TokenStream>,
}

Contents of impl_scope!

impl_scope! input consists of one item (an enum, struct, type alias or union) followed by any number of implementations, and is parsed into this struct.

On its own, impl_scope! provides impl Self syntax, with the following expansion done within Self::expand (after application ScopeAttr rules):

• impl Self { ... } expands to impl #impl_generics #ty_ident #ty_generics #where_clause { ... }
• impl Self where #clause2 { ... } expands similarly, but using the combined where clause

The secondary utility of impl_scope! is to allow attribute expansion within itself via ScopeAttr rules. These rules may read the type item (which may include field initializers in the case of a struct), read accompanying implementations, and even modify them.

Fields

attrs: Vec<Attribute>

Outer attributes on the item

vis: Visibility

Optional pub, etc.

ident: Ident

Item identifier

generics: Generics

Item generics

item: ScopeItem

The item

semi: Option<Semi>

Trailing semicolon (type alias and unit struct only)

impls: Vec<ItemImpl>

Implementation items

generated: Vec<TokenStream>

Output of ScopeAttr rules

This does not contain any content from input, only content generated from ScopeAttr rules. It is appended to output as an item (usually a syn::ImplItem), after Self::impls items.

Implementations

impl Scope

pub fn apply_attrs( &mut self, find_rule: impl Fn(&Path) -> Option<&'static dyn ScopeAttr>, )

Apply attribute rules

The supplied rules are applied in the order of definition, and their attributes removed from the item.

pub fn expand_impl_self(&mut self)

Expand impl Self

This is done automatically by Self::expand. It may be called earlier by a ScopeAttr if required. Calling multiple times is harmless.

pub fn expand(self) -> TokenStream

Generate the TokenStream

This is a convenience function. It is valid to, instead, (1) call Self::expand_impl_self, then (2) use the ToTokens impl on Scope.

Trait Implementations

impl Debug for Scope

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

Formats the value using the given formatter.

impl Parse for Scope

fn parse(input: ParseStream<'_>) -> Result<Self>

impl ToTokens for Scope

fn to_tokens(&self, tokens: &mut TokenStream)

Write self to the given TokenStream.

fn to_token_stream(&self) -> TokenStream

Convert self directly into a TokenStream object.

fn into_token_stream(self) -> TokenStream

where Self: Sized,

Convert self directly into a TokenStream object.