Struct syn::buffer::Cursor

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pub struct Cursor<'a> { /* private fields */ }
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

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<'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

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<'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> 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.