Trait minimal_lexical::Float

pub trait Float: Sized + Copy + PartialEq + PartialOrd + Send + Sync + Add<Output = Self> + AddAssign + Div<Output = Self> + DivAssign + Mul<Output = Self> + MulAssign + Rem<Output = Self> + RemAssign + Sub<Output = Self> + SubAssign + Neg<Output = Self> {
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    // Required methods
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    // Provided methods
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Generic floating-point type, to be used in generic code for parsing.

Although the trait is part of the public API, the trait provides methods and constants that are effectively non-public: they may be removed at any time without any breaking changes.

Required Associated Constants

Maximum number of digits that can contribute in the mantissa.

We can exactly represent a float in radix b from radix 2 if b is divisible by 2. This function calculates the exact number of digits required to exactly represent that float.

According to the “Handbook of Floating Point Arithmetic”, for IEEE754, with emin being the min exponent, p2 being the precision, and b being the radix, the number of digits follows as:

−emin + p2 + ⌊(emin + 1) log(2, b) − log(1 − 2^(−p2), b)⌋

For f32, this follows as: emin = -126 p2 = 24

For f64, this follows as: emin = -1022 p2 = 53

In Python: -emin + p2 + math.floor((emin+1)*math.log(2, b) - math.log(1-2**(-p2), b))

This was used to calculate the maximum number of digits for [2, 36].

Bitmask for the sign bit.

Bitmask for the exponent, including the hidden bit.

Bitmask for the hidden bit in exponent, which is an implicit 1 in the fraction.

Bitmask for the mantissa (fraction), excluding the hidden bit.

Size of the significand (mantissa) without hidden bit.

Bias of the exponet

Exponent portion of a denormal float.

Maximum exponent value in float.

Mask to determine if a full-carry occurred (1 in bit above hidden bit).

Minimum normal exponent value -(1 << (EXPONENT_SIZE - 1)) + 1.

Smallest decimal exponent for a non-zero value.

Largest decimal exponent for a non-infinite value.

Minimum exponent that for a fast path case, or -⌊(MANTISSA_SIZE+1)/log2(10)⌋

Maximum exponent that for a fast path case, or ⌊(MANTISSA_SIZE+1)/log2(5)⌋

Maximum exponent that can be represented for a disguised-fast path case. This is MAX_EXPONENT_FAST_PATH + ⌊(MANTISSA_SIZE+1)/log2(10)⌋

Provided Associated Constants

Bias for marking an invalid extended float.

Required Methods

Convert 64-bit integer to float.

Get a small power-of-radix for fast-path multiplication.

Safety

Safe as long as the exponent is smaller than the table size.

Provided Methods

Get a small, integral power-of-radix for fast-path multiplication.

Safety

Safe as long as the exponent is smaller than the table size.

Returns true if the float is a denormal.

Get exponent component from the float.

Get mantissa (significand) component from float.

Implementations on Foreign Types

impl Float for f32

const MAX_DIGITS: usize = 114usize

const SIGN_MASK: u64 = 2_147_483_648u64

const EXPONENT_MASK: u64 = 2_139_095_040u64

const HIDDEN_BIT_MASK: u64 = 8_388_608u64

const MANTISSA_MASK: u64 = 8_388_607u64

const MANTISSA_SIZE: i32 = 23i32

const EXPONENT_BIAS: i32 = 150i32

const DENORMAL_EXPONENT: i32 = -149i32

const MAX_EXPONENT: i32 = 105i32

const CARRY_MASK: u64 = 16_777_216u64

const MIN_EXPONENT_ROUND_TO_EVEN: i32 = -17i32

const MAX_EXPONENT_ROUND_TO_EVEN: i32 = 10i32

const MINIMUM_EXPONENT: i32 = -127i32

const SMALLEST_POWER_OF_TEN: i32 = -65i32

const LARGEST_POWER_OF_TEN: i32 = 38i32

const MIN_EXPONENT_FAST_PATH: i32 = -10i32

const MAX_EXPONENT_FAST_PATH: i32 = 10i32

const MAX_EXPONENT_DISGUISED_FAST_PATH: i32 = 17i32

unsafe fn pow_fast_path(exponent: usize) -> Self

fn from_u64(u: u64) -> f32

fn from_bits(u: u64) -> f32

fn to_bits(self) -> u64

impl Float for f64

const MAX_DIGITS: usize = 769usize

const SIGN_MASK: u64 = 9_223_372_036_854_775_808u64

const EXPONENT_MASK: u64 = 9_218_868_437_227_405_312u64

const HIDDEN_BIT_MASK: u64 = 4_503_599_627_370_496u64

const MANTISSA_MASK: u64 = 4_503_599_627_370_495u64

const MANTISSA_SIZE: i32 = 52i32

const EXPONENT_BIAS: i32 = 1_075i32

const DENORMAL_EXPONENT: i32 = -1_074i32

const MAX_EXPONENT: i32 = 972i32

const CARRY_MASK: u64 = 9_007_199_254_740_992u64

const MIN_EXPONENT_ROUND_TO_EVEN: i32 = -4i32

const MAX_EXPONENT_ROUND_TO_EVEN: i32 = 23i32

const MINIMUM_EXPONENT: i32 = -1_023i32

const SMALLEST_POWER_OF_TEN: i32 = -342i32

const LARGEST_POWER_OF_TEN: i32 = 308i32

const MIN_EXPONENT_FAST_PATH: i32 = -22i32

const MAX_EXPONENT_FAST_PATH: i32 = 22i32

const MAX_EXPONENT_DISGUISED_FAST_PATH: i32 = 37i32

unsafe fn pow_fast_path(exponent: usize) -> Self

fn from_u64(u: u64) -> f64

fn from_bits(u: u64) -> f64

fn to_bits(self) -> u64

Implementors