Struct FloatLit

pub struct FloatLit<B: Buffer> {
    raw: B,
    end_integer_part: usize,
    end_fractional_part: usize,
    end_number_part: usize,
}

A floating point literal, e.g. 3.14, 8., 135e12, or 1.956e2f64.

This kind of literal has several forms, but generally consists of a main number part, an optional exponent and an optional type suffix. See the reference for more information.

A leading minus sign - is not part of the literal grammar! -3.14 are two tokens in the Rust grammar. Further, 27 and 27f32 are both not float, but integer literals! Consequently FloatLit::parse will reject them.

Fields

raw: B

The whole raw input. The usize fields in this struct partition this string. Always true: end_integer_part <= end_fractional_part.

   12_3.4_56e789f32
       ╷    ╷   ╷
       |    |   └ end_number_part = 13
       |    └ end_fractional_part = 9
       └ end_integer_part = 4

   246.
      ╷╷
      |└ end_fractional_part = end_number_part = 4
      └ end_integer_part = 3

   1234e89
       ╷  ╷
       |  └ end_number_part = 7
       └ end_integer_part = end_fractional_part = 4

end_integer_part: usize

The first index not part of the integer part anymore. Since the integer part is at the start, this is also the length of that part.

end_fractional_part: usize

The first index after the fractional part.

end_number_part: usize

The first index after the whole number part (everything except type suffix).

Implementations

impl<B: Buffer> FloatLit<B>

pub fn parse(s: B) -> Result<Self, ParseError>

Parses the input as a floating point literal. Returns an error if the input is invalid or represents a different kind of literal. Will also reject decimal integer literals like 23 or 17f32, in accordance with the spec.

pub fn number_part(&self) -> &str

Returns the number part (including integer part, fractional part and exponent), but without the suffix. If you want an actual floating point value, you need to parse this string, e.g. with f32::from_str or an external crate.

pub fn integer_part(&self) -> &str

Returns the non-empty integer part of this literal.

pub fn fractional_part(&self) -> Option<&str>

Returns the optional fractional part of this literal. Does not include the period. If a period exists in the input, Some is returned, None otherwise. Note that Some("") might be returned, e.g. for 3..

pub fn exponent_part(&self) -> &str

Optional exponent part. Might be empty if there was no exponent part in the input. Includes the e or E at the beginning.

pub fn suffix(&self) -> &str

The optional suffix. Returns "" if the suffix is empty/does not exist.

pub fn raw_input(&self) -> &str

Returns the raw input that was passed to parse.

pub fn into_raw_input(self) -> B

Returns the raw input that was passed to parse, potentially owned.

impl FloatLit<&str>

pub fn to_owned(&self) -> FloatLit<String>

Makes a copy of the underlying buffer and returns the owned version of Self.

Trait Implementations

impl<B: Clone + Buffer> Clone for FloatLit<B>

fn clone(&self) -> FloatLit<B>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<B: Debug + Buffer> Debug for FloatLit<B>

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

Formats the value using the given formatter.

impl<B: Buffer> Display for FloatLit<B>

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

Formats the value using the given formatter.

impl<B: Buffer> From<FloatLit<B>> for Literal

fn from(l: FloatLit<B>) -> Self

Converts to this type from the input type.

impl<B: Buffer> From<FloatLit<B>> for Literal<B>

fn from(src: FloatLit<B>) -> Self

Converts to this type from the input type.

impl<B: PartialEq + Buffer> PartialEq for FloatLit<B>

fn eq(&self, other: &FloatLit<B>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl TryFrom<&Literal> for FloatLit<String>

type Error = InvalidToken

The type returned in the event of a conversion error.

fn try_from(src: &Literal) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<&TokenTree> for FloatLit<String>

type Error = InvalidToken

The type returned in the event of a conversion error.

fn try_from(tt: &TokenTree) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Literal> for FloatLit<String>

type Error = InvalidToken

The type returned in the event of a conversion error.

fn try_from(src: Literal) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<TokenTree> for FloatLit<String>

type Error = InvalidToken

The type returned in the event of a conversion error.

fn try_from(tt: TokenTree) -> Result<Self, Self::Error>

Performs the conversion.

impl<B: Copy + Buffer> Copy for FloatLit<B>

impl<B: Eq + Buffer> Eq for FloatLit<B>

impl<B: Buffer> StructuralPartialEq for FloatLit<B>