Struct proc_macro::Literal

1.29.0 · source ·
pub struct Literal(/* private fields */);
Expand description

A literal string ("hello"), byte string (b"hello"), character ('a'), byte character (b'a'), an integer or floating point number with or without a suffix (1, 1u8, 2.3, 2.3f32). Boolean literals like true and false do not belong here, they are Idents.

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impl Literal

1.29.0 · source

pub fn u8_suffixed(n: u8) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u16_suffixed(n: u16) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u32_suffixed(n: u32) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u64_suffixed(n: u64) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u128_suffixed(n: u128) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn usize_suffixed(n: usize) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i8_suffixed(n: i8) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i16_suffixed(n: i16) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i32_suffixed(n: i32) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i64_suffixed(n: i64) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i128_suffixed(n: i128) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn isize_suffixed(n: isize) -> Literal

Creates a new suffixed integer literal with the specified value.

This function will create an integer like 1u32 where the integer value specified is the first part of the token and the integral is also suffixed at the end. Literals created from negative numbers might not survive round-trips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u8_unsuffixed(n: u8) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u16_unsuffixed(n: u16) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u32_unsuffixed(n: u32) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u64_unsuffixed(n: u64) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn u128_unsuffixed(n: u128) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn usize_unsuffixed(n: usize) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i8_unsuffixed(n: i8) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i16_unsuffixed(n: i16) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i32_unsuffixed(n: i32) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i64_unsuffixed(n: i64) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn i128_unsuffixed(n: i128) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn isize_unsuffixed(n: isize) -> Literal

Creates a new unsuffixed integer literal with the specified value.

This function will create an integer like 1 where the integer value specified is the first part of the token. No suffix is specified on this token, meaning that invocations like Literal::i8_unsuffixed(1) are equivalent to Literal::u32_unsuffixed(1). Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

Literals created through this method have the Span::call_site() span by default, which can be configured with the set_span method below.

1.29.0 · source

pub fn f32_unsuffixed(n: f32) -> Literal

Creates a new unsuffixed floating-point literal.

This constructor is similar to those like Literal::i8_unsuffixed where the float’s value is emitted directly into the token but no suffix is used, so it may be inferred to be a f64 later in the compiler. Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

§Panics

This function requires that the specified float is finite, for example if it is infinity or NaN this function will panic.

1.29.0 · source

pub fn f32_suffixed(n: f32) -> Literal

Creates a new suffixed floating-point literal.

This constructor will create a literal like 1.0f32 where the value specified is the preceding part of the token and f32 is the suffix of the token. This token will always be inferred to be an f32 in the compiler. Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

§Panics

This function requires that the specified float is finite, for example if it is infinity or NaN this function will panic.

1.29.0 · source

pub fn f64_unsuffixed(n: f64) -> Literal

Creates a new unsuffixed floating-point literal.

This constructor is similar to those like Literal::i8_unsuffixed where the float’s value is emitted directly into the token but no suffix is used, so it may be inferred to be a f64 later in the compiler. Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

§Panics

This function requires that the specified float is finite, for example if it is infinity or NaN this function will panic.

1.29.0 · source

pub fn f64_suffixed(n: f64) -> Literal

Creates a new suffixed floating-point literal.

This constructor will create a literal like 1.0f64 where the value specified is the preceding part of the token and f64 is the suffix of the token. This token will always be inferred to be an f64 in the compiler. Literals created from negative numbers might not survive rountrips through TokenStream or strings and may be broken into two tokens (- and positive literal).

§Panics

This function requires that the specified float is finite, for example if it is infinity or NaN this function will panic.

1.29.0 · source

pub fn string(string: &str) -> Literal

String literal.

1.29.0 · source

pub fn character(ch: char) -> Literal

Character literal.

1.79.0 · source

pub fn byte_character(byte: u8) -> Literal

Byte character literal.

1.29.0 · source

pub fn byte_string(bytes: &[u8]) -> Literal

Byte string literal.

1.79.0 · source

pub fn c_string(string: &CStr) -> Literal

C string literal.

1.29.0 · source

pub fn span(&self) -> Span

Returns the span encompassing this literal.

1.29.0 · source

pub fn set_span(&mut self, span: Span)

Configures the span associated for this literal.

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pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span>

🔬This is a nightly-only experimental API. (proc_macro_span #54725)

Returns a Span that is a subset of self.span() containing only the source bytes in range range. Returns None if the would-be trimmed span is outside the bounds of self.

Trait Implementations§

1.29.0 · source§

impl Clone for Literal

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fn clone(&self) -> Literal

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
1.29.0 · source§

impl Debug for Literal

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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 Display for Literal

Prints the literal as a string that should be losslessly convertible back into the same literal (except for possible rounding for floating point literals).

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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 From<Literal> for TokenTree

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fn from(g: Literal) -> TokenTree

Converts to this type from the input type.
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impl FromStr for Literal

Parse a single literal from its stringified representation.

In order to parse successfully, the input string must not contain anything but the literal token. Specifically, it must not contain whitespace or comments in addition to the literal.

The resulting literal token will have a Span::call_site() span.

NOTE: some errors may cause panics instead of returning LexError. We reserve the right to change these errors into LexErrors later.

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type Err = LexError

The associated error which can be returned from parsing.
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fn from_str(src: &str) -> Result<Self, LexError>

Parses a string s to return a value of this type. Read more

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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 T)

🔬This is a nightly-only experimental API. (clone_to_uninit #126799)
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> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. 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.