Struct malachite_base::num::float::NiceFloat

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pub struct NiceFloat<T: PrimitiveFloat>(pub T);

Expand description

NiceFloat is a wrapper around primitive float types that provides nicer Eq, Ord, Hash, Display, and FromStr instances.

In most languages, floats behave weirdly due to the IEEE 754 standard. The NiceFloat type ignores the standard in favor of more intuitive behavior.

Using NiceFloat, NaNs are equal to themselves. There is a single, unique NaN; there’s no concept of signalling NaNs. Positive and negative zero are two distinct values, not equal to each other.
The NiceFloat hash respects this equality.
NiceFloat has a total order. These are the classes of floats, in ascending order:
- Negative infinity
- Negative nonzero finite floats
- Negative zero
- NaN
- Positive zero
- Positive nonzero finite floats
- Positive infinity
NiceFloat uses a different Display implementation than floats do by default in Rust. For example, Rust will format f32::MIN_POSITIVE_SUBNORMAL as something with many zeros, but NiceFloat(f32::MIN_POSITIVE_SUBNORMAL) just formats it as "1.0e-45". The conversion function uses David Tolnay’s ryu crate, with a few modifications:
- All finite floats have a decimal point. For example, Ryu by itself would convert f32::MIN_POSITIVE_SUBNORMAL to "1e-45".
- Positive infinity, negative infinity, and NaN are converted to the strings "Infinity", "-Infinity", and “NaN”, respectively.
FromStr accepts these strings.

Tuple Fields

0: T

Trait Implementations

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impl<T: Clone + PrimitiveFloat> Clone for NiceFloat<T>

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fn clone(&self) -> NiceFloat<T>

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

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impl<T: PrimitiveFloat> Debug for NiceFloat<T>

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

Formats a NiceFloat as a string.

This is identical to the Display::fmt implementation.

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impl<T: Default + PrimitiveFloat> Default for NiceFloat<T>

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fn default() -> NiceFloat<T>

Returns the “default value” for a type. Read more

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impl<T: PrimitiveFloat> Display for NiceFloat<T>

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

Formats a NiceFloat as a string.

NiceFloat uses a different Display implementation than floats do by default in Rust. For example, Rust will convert f32::MIN_POSITIVE_SUBNORMAL to something with many zeros, but NiceFloat(f32::MIN_POSITIVE_SUBNORMAL) just converts to "1.0e-45". The conversion function uses David Tolnay’s ryu crate, with a few modifications:

All finite floats have a decimal point. For example, Ryu by itself would convert f32::MIN_POSITIVE_SUBNORMAL to "1e-45".
Positive infinity, negative infinity, and NaN are converted to the strings "Infinity", "-Infinity", and “NaN”, respectively.

Worst-case complexity

Constant time and additional memory.

Examples

use malachite_base::num::basic::floats::PrimitiveFloat;
use malachite_base::num::float::NiceFloat;

assert_eq!(NiceFloat(0.0).to_string(), "0.0");
assert_eq!(NiceFloat(-0.0).to_string(), "-0.0");
assert_eq!(NiceFloat(f32::POSITIVE_INFINITY).to_string(), "Infinity");
assert_eq!(NiceFloat(f32::NEGATIVE_INFINITY).to_string(), "-Infinity");
assert_eq!(NiceFloat(f32::NAN).to_string(), "NaN");

assert_eq!(NiceFloat(1.0).to_string(), "1.0");
assert_eq!(NiceFloat(-1.0).to_string(), "-1.0");
assert_eq!(
    NiceFloat(f32::MIN_POSITIVE_SUBNORMAL).to_string(),
    "1.0e-45"
);
assert_eq!(
    NiceFloat(std::f64::consts::E).to_string(),
    "2.718281828459045"
);
assert_eq!(
    NiceFloat(std::f64::consts::PI).to_string(),
    "3.141592653589793"
);

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impl<T: PrimitiveFloat> FromStr for NiceFloat<T>

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fn from_str(src: &str) -> Result<NiceFloat<T>, <T as FromStr>::Err>

Converts a &str to a NiceFloat.

If the &str does not represent a valid NiceFloat, an Err is returned.

Worst-case complexity

$T(n) = O(n)$

$M(n) = O(1)$

where $T$ is time, $M$ is additional memory, and $n$ = src.len().

Examples

use malachite_base::num::float::NiceFloat;
use std::str::FromStr;

assert_eq!(NiceFloat::from_str("NaN").unwrap(), NiceFloat(f32::NAN));
assert_eq!(NiceFloat::from_str("-0.00").unwrap(), NiceFloat(-0.0f64));
assert_eq!(NiceFloat::from_str(".123").unwrap(), NiceFloat(0.123f32));

type Err = <T as FromStr>::Err

The associated error which can be returned from parsing.

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impl<T: PrimitiveFloat> Hash for NiceFloat<T>

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

Computes a hash of a NiceFloat.

The hash is compatible with NiceFloat equality: all NaNs hash to the same value.

Worst-case complexity

Constant time and additional memory.

1.3.0 · source

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

Feeds a slice of this type into the given Hasher. Read more

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impl<T: PrimitiveFloat> Ord for NiceFloat<T>

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fn cmp(&self, other: &NiceFloat<T>) -> Ordering

Compares two NiceFloats.

This implementation ignores the IEEE 754 standard in favor of an equality operation that respects the expected properties of symmetry, reflexivity, and transitivity. Using NiceFloat, NaNs are equal to themselves. There is a single, unique NaN; there’s no concept of signalling NaNs. Positive and negative zero are two distinct values, not equal to each other.

Worst-case complexity

Constant time and additional memory.

Examples

use malachite_base::num::basic::floats::PrimitiveFloat;
use malachite_base::num::float::NiceFloat;

assert!(NiceFloat(0.0) > NiceFloat(-0.0));
assert!(NiceFloat(f32::NAN) < NiceFloat(0.0));
assert!(NiceFloat(f32::NAN) > NiceFloat(-0.0));
assert!(NiceFloat(f32::POSITIVE_INFINITY) > NiceFloat(f32::NAN));
assert!(NiceFloat(f32::NAN) < NiceFloat(1.0));

1.21.0 · source

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values. Read more

1.21.0 · source

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values. Read more

1.50.0 · source

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval. Read more

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impl<T: PrimitiveFloat> PartialEq<NiceFloat<T>> for NiceFloat<T>

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fn eq(&self, other: &NiceFloat<T>) -> bool

Compares two NiceFloats for equality.

This implementation ignores the IEEE 754 standard in favor of a comparison operation that respects the expected properties of antisymmetry, reflexivity, and transitivity. NiceFloat has a total order. These are the classes of floats, in ascending order:

Negative infinity
Negative nonzero finite floats
Negative zero
NaN
Positive zero
Positive nonzero finite floats
Positive infinity

Worst-case complexity

Constant time and additional memory.

Examples

use malachite_base::num::float::NiceFloat;

assert_eq!(NiceFloat(0.0), NiceFloat(0.0));
assert_eq!(NiceFloat(f32::NAN), NiceFloat(f32::NAN));
assert_ne!(NiceFloat(f32::NAN), NiceFloat(0.0));
assert_ne!(NiceFloat(0.0), NiceFloat(-0.0));
assert_eq!(NiceFloat(1.0), NiceFloat(1.0));

1.0.0 · source

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

This method tests for !=.

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impl<T: PrimitiveFloat> PartialOrd<NiceFloat<T>> for NiceFloat<T>

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fn partial_cmp(&self, other: &NiceFloat<T>) -> Option<Ordering>

Compares a NiceFloat to another NiceFloat.

See the documentation for the Ord implementation.

1.0.0 · source

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

This method tests less than (for self and other) and is used by the < operator. Read more

1.0.0 · source

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

1.0.0 · source

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

This method tests greater than (for self and other) and is used by the > operator. Read more

1.0.0 · source

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<T: Copy + PrimitiveFloat> Copy for NiceFloat<T>

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impl<T: PrimitiveFloat> Eq for NiceFloat<T>

Auto Trait Implementations

impl<T> RefUnwindSafe for NiceFloat<T> where
T: RefUnwindSafe,

impl<T> Send for NiceFloat<T> where
T: Send,

impl<T> Sync for NiceFloat<T> where
T: Sync,

impl<T> Unpin for NiceFloat<T> where
T: Unpin,

impl<T> UnwindSafe for NiceFloat<T> where
T: UnwindSafe,

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,

const: unstable · source

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,

const: unstable · source

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into for T where
U: From<T>,

const: unstable · source

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, U> OverflowingInto for T where
U: OverflowingFrom<T>,

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fn overflowing_into(self) -> (U, bool )

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impl<T, U> RoundingInto for T where
U: RoundingFrom<T>,

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fn rounding_into(self, rm: RoundingMode) -> U

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impl<T> Same<T> for T

type Output = T

Should always be Self

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impl<T, U> SaturatingInto for T where
U: SaturatingFrom<T>,

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fn saturating_into(self) -> U

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impl<T> ToDebugString for T where
T: Debug,

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fn to_debug_string(&self) -> String

Returns the String produced by Ts Debug implementation.

Examples

use malachite_base::strings::ToDebugString;

assert_eq!([1, 2, 3].to_debug_string(), "[1, 2, 3]");
assert_eq!(
    [vec![2, 3], vec![], vec![4]].to_debug_string(),
    "[[2, 3], [], [4]]"
);
assert_eq!(Some(5).to_debug_string(), "Some(5)");

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impl<T> ToOwned for T where
T: Clone,

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 for T where
U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

fn try_from(value: U) -> Result<T, <T as TryFrom>::Error>

Performs the conversion.

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impl<T, U> TryInto for T where
U: TryFrom<T>,

type Error = >::Error

The type returned in the event of a conversion error.

const: unstable · source

fn try_into(self) -> Result<U, >::Error>

Performs the conversion.

impl<V, T> VZip<V> for T where
V: MultiLane<T>,

fn vzip(self) -> V

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impl<T, U> WrappingInto for T where
U: WrappingFrom<T>,

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Struct malachite_base::num::float::NiceFloat

Tuple Fields

Trait Implementations

impl<T: Clone + PrimitiveFloat> Clone for NiceFloat<T>

fn clone(&self) -> NiceFloat<T>

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

impl<T: PrimitiveFloat> Debug for NiceFloat<T>

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

impl<T: Default + PrimitiveFloat> Default for NiceFloat<T>

fn default() -> NiceFloat<T>

impl<T: PrimitiveFloat> Display for NiceFloat<T>

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

impl<T: PrimitiveFloat> FromStr for NiceFloat<T>

fn from_str(src: &str) -> Result<NiceFloat<T>, <T as FromStr>::Err>

type Err = <T as FromStr>::Err

impl<T: PrimitiveFloat> Hash for NiceFloat<T>

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

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

impl<T: PrimitiveFloat> Ord for NiceFloat<T>

fn cmp(&self, other: &NiceFloat<T>) -> Ordering

fn max(self, other: Self) -> Self

fn min(self, other: Self) -> Self

fn clamp(self, min: Self, max: Self) -> Self

impl<T: PrimitiveFloat> PartialEq<NiceFloat<T>> for NiceFloat<T>

fn eq(&self, other: &NiceFloat<T>) -> bool

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

impl<T: PrimitiveFloat> PartialOrd<NiceFloat<T>> for NiceFloat<T>

fn partial_cmp(&self, other: &NiceFloat<T>) -> Option<Ordering>

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

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

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

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

impl<T: Copy + PrimitiveFloat> Copy for NiceFloat<T>

impl<T: PrimitiveFloat> Eq for NiceFloat<T>

Auto Trait Implementations

impl<T> RefUnwindSafe for NiceFloat<T> where T: RefUnwindSafe,

impl<T> Send for NiceFloat<T> where T: Send,

impl<T> Sync for NiceFloat<T> where T: Sync,

impl<T> Unpin for NiceFloat<T> where T: Unpin,

impl<T> UnwindSafe for NiceFloat<T> where T: UnwindSafe,

Blanket Implementations

impl<T> Any for T where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for T where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for T where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T, U> CheckedInto<U> for T where U: CheckedFrom<T>,

fn checked_into(self) -> Option<U>

impl<T, U> ExactInto<U> for T where U: ExactFrom<T>,

fn exact_into(self) -> U

impl<T> From<T> for T

fn from(t: T) -> T

impl<T, U> Into<U> for T where U: From<T>,

fn into(self) -> U

impl<T, U> OverflowingInto<U> for T where U: OverflowingFrom<T>,

fn overflowing_into(self) -> (U, bool)

impl<T, U> RoundingInto<U> for T where U: RoundingFrom<T>,

fn rounding_into(self, rm: RoundingMode) -> U

impl<T> Same<T> for T

type Output = T

impl<T, U> SaturatingInto<U> for T where U: SaturatingFrom<T>,

fn saturating_into(self) -> U

impl<T> ToDebugString for T where T: Debug,

fn to_debug_string(&self) -> String

impl<T> ToOwned for T where T: Clone,

type Owned = T

fn to_owned(&self) -> T

fn clone_into(&self, target: &mut T)

impl<T> ToString for T where T: Display + ?Sized,

default fn to_string(&self) -> String

impl<T, U> TryFrom<U> for T where U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<T, U> TryInto<U> for T where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

impl<V, T> VZip<V> for T where V: MultiLane<T>,

fn vzip(self) -> V

impl<T, U> WrappingInto<U> for T where U: WrappingFrom<T>,

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

impl<T> RefUnwindSafe for NiceFloat<T> where
T: RefUnwindSafe,

impl<T> Send for NiceFloat<T> where
T: Send,

impl<T> Sync for NiceFloat<T> where
T: Sync,

impl<T> Unpin for NiceFloat<T> where
T: Unpin,

impl<T> UnwindSafe for NiceFloat<T> where
T: UnwindSafe,

impl<T> Any for T where
T: 'static + ?Sized,

impl<T> Borrow<T> for T where
T: ?Sized,

impl<T> BorrowMut<T> for T where
T: ?Sized,

impl<T, U> CheckedInto<U> for T where
U: CheckedFrom<T>,

impl<T, U> ExactInto<U> for T where
U: ExactFrom<T>,

impl<T, U> Into<U> for T where
U: From<T>,

impl<T, U> OverflowingInto<U> for T where
U: OverflowingFrom<T>,

fn overflowing_into(self) -> (U, bool )

impl<T, U> RoundingInto<U> for T where
U: RoundingFrom<T>,

impl<T, U> SaturatingInto<U> for T where
U: SaturatingFrom<T>,

impl<T> ToDebugString for T where
T: Debug,

impl<T> ToOwned for T where
T: Clone,

impl<T> ToString for T where
T: Display + ?Sized,

impl<T, U> TryFrom<U> for T where
U: Into<T>,

impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

impl<V, T> VZip<V> for T where
V: MultiLane<T>,

impl<T, U> WrappingInto<U> for T where
U: WrappingFrom<T>,