syn::buffer

Struct Cursor

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pub struct Cursor<'a> { /* private fields */ }
Available on crate feature parsing only.
Expand description

A cheaply copyable cursor into a TokenBuffer.

This cursor holds a shared reference into the immutable data which is used internally to represent a TokenStream, and can be efficiently manipulated and copied around.

An empty Cursor can be created directly, or one may create a TokenBuffer object and get a cursor to its first token with begin().

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impl<'a> Cursor<'a>

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pub fn empty() -> Self

Creates a cursor referencing a static empty TokenStream.

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pub fn eof(self) -> bool

Checks whether the cursor is currently pointing at the end of its valid scope.

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pub fn group( self, delim: Delimiter, ) -> Option<(Cursor<'a>, DelimSpan, Cursor<'a>)>

If the cursor is pointing at a Group with the given delimiter, returns a cursor into that group and one pointing to the next TokenTree.

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pub fn ident(self) -> Option<(Ident, Cursor<'a>)>

If the cursor is pointing at a Ident, returns it along with a cursor pointing at the next TokenTree.

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pub fn punct(self) -> Option<(Punct, Cursor<'a>)>

If the cursor is pointing at a Punct, returns it along with a cursor pointing at the next TokenTree.

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pub fn literal(self) -> Option<(Literal, Cursor<'a>)>

If the cursor is pointing at a Literal, return it along with a cursor pointing at the next TokenTree.

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pub fn lifetime(self) -> Option<(Lifetime, Cursor<'a>)>

If the cursor is pointing at a Lifetime, returns it along with a cursor pointing at the next TokenTree.

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pub fn token_stream(self) -> TokenStream

Copies all remaining tokens visible from this cursor into a TokenStream.

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pub fn token_tree(self) -> Option<(TokenTree, Cursor<'a>)>

If the cursor is pointing at a TokenTree, returns it along with a cursor pointing at the next TokenTree.

Returns None if the cursor has reached the end of its stream.

This method does not treat None-delimited groups as transparent, and will return a Group(None, ..) if the cursor is looking at one.

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pub fn span(self) -> Span

Returns the Span of the current token, or Span::call_site() if this cursor points to eof.

Trait Implementations§

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impl<'a> Clone for Cursor<'a>

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fn clone(&self) -> Self

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<'a> PartialEq for Cursor<'a>

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<'a> PartialOrd for Cursor<'a>

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fn partial_cmp(&self, other: &Self) -> 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

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

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

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

Tests greater than or equal to (for self and other) and is used by the >= operator. Read more
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impl<'a> Copy for Cursor<'a>

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impl<'a> Eq for Cursor<'a>

Auto Trait Implementations§

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impl<'a> Freeze for Cursor<'a>

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impl<'a> RefUnwindSafe for Cursor<'a>

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impl<'a> !Send for Cursor<'a>

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impl<'a> !Sync for Cursor<'a>

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impl<'a> Unpin for Cursor<'a>

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impl<'a> UnwindSafe for Cursor<'a>

Blanket Implementations§

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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> 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> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dst: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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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, 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> 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.

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: 16 bytes