Enum FloatKind

pub enum FloatKind {
    NaN,
    Zero,
    Normal(u64, u32, bool),
    Overflow(bool),
    Infinity,
}

Float Type.

This enum provides basic float classification. It is used by NiceFloat for formatting, but may be useful in other contexts too. Enjoy!

Examples

use dactyl::FloatKind;

// Weird things.
assert_eq!(FloatKind::from(f64::NAN), FloatKind::NaN);
assert_eq!(FloatKind::from(f64::INFINITY), FloatKind::Infinity);
assert_eq!(FloatKind::from(f64::NEG_INFINITY), FloatKind::Infinity);

// Really big or small values can't be parsed out.
assert_eq!(FloatKind::from(f64::MIN), FloatKind::Overflow(true));
assert_eq!(FloatKind::from(f64::MAX), FloatKind::Overflow(false));

// Normal things.
assert_eq!(FloatKind::from(0_f32), FloatKind::Zero);
assert_eq!(FloatKind::from(123.456_f64), FloatKind::Normal(123, 45600000, false));
assert_eq!(FloatKind::from(-123.456_f64), FloatKind::Normal(123, 45600000, true));

As mentioned elsewhere, Rust floats are imprecise. Any imprecision within the original float will come through in the parsed FloatKind.

use dactyl::FloatKind;

// This is right, but wrong. Haha.
assert_eq!(
    FloatKind::from(1234.5678_f32),
    FloatKind::Normal(1234, 56774902, false),
);

Variants

NaN

Not a Number.

Zero

Zero.

This does not differentiate between positive and negative zero; they’re just zero…

Normal(u64, u32, bool)

Normal.

This holds the integer and fractional parts of the float, along with a bool indicating whether or not it was negative.

The integer range must fit within u64; larger (absolute) values will fall back to FloatKind::Overflow.

The fractional range holds up to eight digits, rounding on the ninth using a tie-to-even strategy.

Overflow(bool)

Overflow.

The value is normal, but is too big to be nicely split. The bool indicates whether or not the value is negative.

Infinity

Infinity.

This does not differentiate between positive and negative infinity; the point is the numbers go on and on and on…

Trait Implementations

impl Clone for FloatKind

fn clone(&self) -> FloatKind

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FloatKind

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

Formats the value using the given formatter.

impl Default for FloatKind

fn default() -> FloatKind

Returns the “default value” for a type.

impl From<FloatKind> for NiceFloat

fn from(kind: FloatKind) -> Self

Converts to this type from the input type.

impl From<f32> for FloatKind

fn from(num: f32) -> Self

Converts to this type from the input type.

impl From<f64> for FloatKind

fn from(num: f64) -> Self

Converts to this type from the input type.

impl Hash for FloatKind

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

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for FloatKind

fn eq(&self, other: &FloatKind) -> 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 Copy for FloatKind

impl Eq for FloatKind

impl StructuralPartialEq for FloatKind