pub struct SyntaxContext(/* private fields */);
Expand description

A SyntaxContext represents a chain of macro expansions (represented by marks).

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impl SyntaxContext

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pub const fn empty() -> Self

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pub fn has_mark(self, mark: Mark) -> bool

Returns true if self is marked with mark.

Panics if mark is not a valid mark.

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pub fn as_u32(self) -> u32

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pub fn from_u32(raw: u32) -> SyntaxContext

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pub fn apply_mark(self, mark: Mark) -> SyntaxContext

Extend a syntax context with a given mark and default transparency for that mark.

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pub fn remove_mark(&mut self) -> Mark

Pulls a single mark off of the syntax context. This effectively moves the context up one macro definition level. That is, if we have a nested macro definition as follows:

macro_rules! f {
   macro_rules! g {
       ...
   }
}

and we have a SyntaxContext that is referring to something declared by an invocation of g (call it g1), calling remove_mark will result in the SyntaxContext for the invocation of f that created g1. Returns the mark that was removed.

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pub fn adjust(&mut self, expansion: Mark) -> Option<Mark>

Adjust this context for resolution in a scope created by the given expansion. For example, consider the following three resolutions of f:

mod foo {
    pub fn f() {}
} // `f`'s `SyntaxContext` is empty.
m!(f);
macro m($f:ident) {
    mod bar {
        pub fn f() {} // `f`'s `SyntaxContext` has a single `Mark` from `m`.
        pub fn $f() {} // `$f`'s `SyntaxContext` is empty.
    }
    foo::f(); // `f`'s `SyntaxContext` has a single `Mark` from `m`
              //^ Since `mod foo` is outside this expansion, `adjust` removes the mark from `f`,
              //| and it resolves to `::foo::f`.
    bar::f(); // `f`'s `SyntaxContext` has a single `Mark` from `m`
              //^ Since `mod bar` not outside this expansion, `adjust` does not change `f`,
              //| and it resolves to `::bar::f`.
    bar::$f(); // `f`'s `SyntaxContext` is empty.
               //^ Since `mod bar` is not outside this expansion, `adjust` does not change `$f`,
               //| and it resolves to `::bar::$f`.
}

This returns the expansion whose definition scope we use to privacy check the resolution, or None if we privacy check as usual (i.e. not w.r.t. a macro definition scope).

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pub fn glob_adjust( &mut self, expansion: Mark, glob_ctxt: SyntaxContext ) -> Option<Option<Mark>>

Adjust this context for resolution in a scope created by the given expansion via a glob import with the given SyntaxContext. For example:

m!(f);
macro m($i:ident) {
    mod foo {
        pub fn f() {} // `f`'s `SyntaxContext` has a single `Mark` from `m`.
        pub fn $i() {} // `$i`'s `SyntaxContext` is empty.
    }
    n(f);
    macro n($j:ident) {
        use foo::*;
        f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n`
             //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::f`.
        $i(); // `$i`'s `SyntaxContext` has a mark from `n`
              //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::$i`.
        $j(); // `$j`'s `SyntaxContext` has a mark from `m`
              //^ This cannot be glob-adjusted, so this is a resolution error.
    }
}

This returns None if the context cannot be glob-adjusted. Otherwise, it returns the scope to use when privacy checking (see adjust for details).

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pub fn reverse_glob_adjust( &mut self, expansion: Mark, glob_ctxt: SyntaxContext ) -> Option<Option<Mark>>

Undo glob_adjust if possible:

if let Some(privacy_checking_scope) = self.reverse_glob_adjust(expansion, glob_ctxt) {
    assert!(self.glob_adjust(expansion, glob_ctxt) == Some(privacy_checking_scope));
}
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pub fn outer(self) -> Mark

Trait Implementations§

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impl Archive for SyntaxContext

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type Archived = ArchivedSyntaxContext

The archived representation of this type. Read more
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type Resolver = SyntaxContextResolver

The resolver for this type. It must contain all the additional information from serializing needed to make the archived type from the normal type.
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unsafe fn resolve( &self, pos: usize, resolver: Self::Resolver, out: *mut Self::Archived )

Creates the archived version of this value at the given position and writes it to the given output. Read more
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impl Clone for SyntaxContext

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fn clone(&self) -> SyntaxContext

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for SyntaxContext

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

Formats the value using the given formatter. Read more
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impl Default for SyntaxContext

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fn default() -> SyntaxContext

Returns the “default value” for a type. Read more
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impl<'de> Deserialize<'de> for SyntaxContext

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fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>
where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more
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impl<__D: Fallible + ?Sized> Deserialize<SyntaxContext, __D> for Archived<SyntaxContext>

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fn deserialize( &self, deserializer: &mut __D ) -> Result<SyntaxContext, __D::Error>

Deserializes using the given deserializer
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impl EqIgnoreSpan for SyntaxContext

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fn eq_ignore_span(&self, other: &Self) -> bool

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impl Hash for SyntaxContext

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fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl Ord for SyntaxContext

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fn cmp(&self, other: &SyntaxContext) -> Ordering

This method returns an Ordering between self and other. Read more
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fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
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fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
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fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
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impl PartialEq for SyntaxContext

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

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

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fn partial_cmp(&self, other: &SyntaxContext) -> Option<Ordering>

This method returns an ordering between self and other values if one exists. Read more
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fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
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impl<__S: Fallible + ?Sized> Serialize<__S> for SyntaxContext

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fn serialize(&self, serializer: &mut __S) -> Result<Self::Resolver, __S::Error>

Writes the dependencies for the object and returns a resolver that can create the archived type.
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impl Serialize for SyntaxContext

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fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>
where __S: Serializer,

Serialize this value into the given Serde serializer. Read more
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impl TypeEq for SyntaxContext

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fn type_eq(&self, other: &Self) -> bool

Note: This method should return true for non-type values.
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impl Copy for SyntaxContext

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impl Eq for SyntaxContext

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impl StructuralPartialEq for SyntaxContext

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> ArchivePointee for T

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type ArchivedMetadata = ()

The archived version of the pointer metadata for this type.
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fn pointer_metadata( _: &<T as ArchivePointee>::ArchivedMetadata ) -> <T as Pointee>::Metadata

Converts some archived metadata to the pointer metadata for itself.
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impl<T> ArchiveUnsized for T
where T: Archive,

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type Archived = <T as Archive>::Archived

The archived counterpart of this type. Unlike Archive, it may be unsized. Read more
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type MetadataResolver = ()

The resolver for the metadata of this type. Read more
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unsafe fn resolve_metadata( &self, _: usize, _: <T as ArchiveUnsized>::MetadataResolver, _: *mut <<T as ArchiveUnsized>::Archived as ArchivePointee>::ArchivedMetadata )

Creates the archived version of the metadata for this value at the given position and writes it to the given output. Read more
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unsafe fn resolve_unsized( &self, from: usize, to: usize, resolver: Self::MetadataResolver, out: *mut RelPtr<Self::Archived, <isize as Archive>::Archived> )

Resolves a relative pointer to this value with the given from and to and writes it to the given output. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CallHasher for T
where T: Hash + ?Sized,

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default fn get_hash<H, B>(value: &H, build_hasher: &B) -> u64
where H: Hash + ?Sized, B: BuildHasher,

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impl<F, W, T, D> Deserialize<With<T, W>, D> for F
where W: DeserializeWith<F, T, D>, D: Fallible + ?Sized, F: ?Sized,

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fn deserialize( &self, deserializer: &mut D ) -> Result<With<T, W>, <D as Fallible>::Error>

Deserializes using the given deserializer
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

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

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impl<T> LayoutRaw for T

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fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>

Gets the layout of the type.
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impl<T> Pointee for T

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type Metadata = ()

The type for metadata in pointers and references to Self.
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impl<T, S> SerializeUnsized<S> for T
where T: Serialize<S>, S: Serializer + ?Sized,

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fn serialize_unsized( &self, serializer: &mut S ) -> Result<usize, <S as Fallible>::Error>

Writes the object and returns the position of the archived type.
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fn serialize_metadata(&self, _: &mut S) -> Result<(), <S as Fallible>::Error>

Serializes the metadata for the given type.
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more
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impl<T> DeserializeOwned for T
where T: for<'de> Deserialize<'de>,