Struct fixed_decimal::FixedDecimal

pub struct FixedDecimal { /* private fields */ }

A struct containing decimal digits with efficient iteration and manipulation by magnitude (power of 10).

Supports a mantissa of non-zero digits and a number of leading and trailing zeros, as well as an optional sign; used for formatting and plural selection.

Data Types

The following types can be converted to a FixedDecimal:

• Integers, signed and unsigned
• Strings representing an arbitrary-precision decimal
• Floating point values (using the ryu feature)

To create a FixedDecimal with fraction digits, either create it from an integer and then call FixedDecimal::multiplied_pow10, create it from a string, or (when the ryu feature is enabled) create it from a floating point value using FixedDecimal::try_from_f64.

Magnitude and Position

Each digit in a FixedDecimal is indexed by a magnitude, or the digit’s power of 10. Illustration for the number “12.34”:

Magnitude	Digit	Description
1	1	Tens place
0	2	Ones place
-1	3	Tenths place
-2	4	Hundredths place

Some functions deal with a position for the purpose of padding, truncating, or rounding a number. In these cases, the position sits between the corresponding magnitude of that position and the next lower significant digit. Illustration:

Position:   2   0  -2
Number:     |1|2.3|4|
Position:     1  -1

Expected output of various operations, all with input “12.34”:

Operation	Position	Expected Result
Truncate to tens	1	10
Truncate to tenths	-1	12.3
Pad to ten thousands	4	0012.34
Pad to ten thousandths	-4	12.3400

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(250);
assert_eq!("250", dec.to_string());

dec.multiply_pow10(-2);
assert_eq!("2.50", dec.to_string());

Implementations

impl FixedDecimal

pub fn digit_at(&self, magnitude: i16) -> u8

Gets the digit at the specified order of magnitude. Returns 0 if the magnitude is out of range of the currently visible digits.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from(945);
assert_eq!(0, dec.digit_at(-1));
assert_eq!(5, dec.digit_at(0));
assert_eq!(4, dec.digit_at(1));
assert_eq!(9, dec.digit_at(2));
assert_eq!(0, dec.digit_at(3));

pub const fn magnitude_range(&self) -> RangeInclusive<i16>

Gets the visible range of digit magnitudes, in ascending order of magnitude. Call .rev() on the return value to get the range in descending order. Magnitude 0 is always included, even if the number has leading or trailing zeros.

Examples

use fixed_decimal::FixedDecimal;

let dec: FixedDecimal = "012.340".parse().expect("valid syntax");
assert_eq!(-3..=2, dec.magnitude_range());

pub fn nonzero_magnitude_start(&self) -> i16

Gets the magnitude of the largest nonzero digit. If the number is zero, 0 is returned.

Examples

use fixed_decimal::FixedDecimal;

let dec: FixedDecimal = "012.340".parse().expect("valid syntax");
assert_eq!(1, dec.nonzero_magnitude_start());

assert_eq!(0, FixedDecimal::from(0).nonzero_magnitude_start());

pub fn nonzero_magnitude_end(&self) -> i16

Gets the magnitude of the smallest nonzero digit. If the number is zero, 0 is returned.

Examples

use fixed_decimal::FixedDecimal;

let dec: FixedDecimal = "012.340".parse().expect("valid syntax");
assert_eq!(-2, dec.nonzero_magnitude_end());

assert_eq!(0, FixedDecimal::from(0).nonzero_magnitude_end());

pub fn is_zero(&self) -> bool

Returns whether the number has a numeric value of zero.

Examples

use fixed_decimal::FixedDecimal;

let dec: FixedDecimal = "000.000".parse().expect("valid syntax");
assert!(dec.is_zero());

pub fn multiply_pow10(&mut self, delta: i16)

Shift the digits of this number by a power of 10.

Leading or trailing zeros may be added to keep the digit at magnitude 0 (the last digit before the decimal separator) visible.

NOTE: if the operation causes overflow, the number will be set to zero.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(42);
assert_eq!("42", dec.to_string());

dec.multiply_pow10(3);
assert_eq!("42000", dec.to_string());

pub fn multiplied_pow10(self, delta: i16) -> Self

Returns this number with its digits shifted by a power of 10.

Leading or trailing zeros may be added to keep the digit at magnitude 0 (the last digit before the decimal separator) visible.

NOTE: if the operation causes overflow, the returned number will be zero.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from(42).multiplied_pow10(3);
assert_eq!("42000", dec.to_string());

pub fn sign(&self) -> Sign

Returns the sign of this number.

Examples

use fixed_decimal::FixedDecimal;
use fixed_decimal::Sign;

assert_eq!(FixedDecimal::from_str("1729").unwrap().sign(), Sign::None);
assert_eq!(
    FixedDecimal::from_str("-1729").unwrap().sign(),
    Sign::Negative
);
assert_eq!(
    FixedDecimal::from_str("+1729").unwrap().sign(),
    Sign::Positive
);

pub fn set_sign(&mut self, sign: Sign)

Changes the sign of this number to the one given.

Examples

use fixed_decimal::FixedDecimal;
use fixed_decimal::Sign;

let mut dec = FixedDecimal::from(1729);
assert_eq!("1729", dec.to_string());

dec.set_sign(Sign::Negative);
assert_eq!("-1729", dec.to_string());

dec.set_sign(Sign::Positive);
assert_eq!("+1729", dec.to_string());

dec.set_sign(Sign::None);
assert_eq!("1729", dec.to_string());

pub fn with_sign(self, sign: Sign) -> Self

Returns this number with the sign changed to the one given.

Examples

use fixed_decimal::FixedDecimal;
use fixed_decimal::Sign;

assert_eq!(
    "+1729",
    FixedDecimal::from(1729)
        .with_sign(Sign::Positive)
        .to_string()
);
assert_eq!(
    "1729",
    FixedDecimal::from(-1729).with_sign(Sign::None).to_string()
);
assert_eq!(
    "-1729",
    FixedDecimal::from(1729)
        .with_sign(Sign::Negative)
        .to_string()
);

pub fn apply_sign_display(&mut self, sign_display: SignDisplay)

Sets the sign of this number according to the given sign display strategy.

Examples

use fixed_decimal::FixedDecimal;
use fixed_decimal::SignDisplay::*;

let mut dec = FixedDecimal::from(1729);
assert_eq!("1729", dec.to_string());
dec.apply_sign_display(Always);
assert_eq!("+1729", dec.to_string());

pub fn with_sign_display(self, sign_display: SignDisplay) -> Self

Returns this number with its sign set according to the given sign display strategy.

Examples

use fixed_decimal::FixedDecimal;
use fixed_decimal::SignDisplay::*;

assert_eq!(
    "+1729",
    FixedDecimal::from(1729)
        .with_sign_display(ExceptZero)
        .to_string()
);

pub fn trimmed_start(self) -> Self

Returns this number with its leading zeroes removed.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from(123400)
    .multiplied_pow10(-4)
    .padded_start(4);
assert_eq!("0012.3400", dec.to_string());

assert_eq!("12.3400", dec.trimmed_start().to_string());

pub fn trim_start(&mut self)

Removes the leading zeroes of this number.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(123400)
    .multiplied_pow10(-4)
    .padded_start(4);
assert_eq!("0012.3400", dec.to_string());

dec.trim_start();
assert_eq!("12.3400", dec.to_string());

There is no effect if the most significant digit has magnitude less than zero:

let mut dec = FixedDecimal::from(22).multiplied_pow10(-4);
assert_eq!("0.0022", dec.to_string());

dec.trim_start();
assert_eq!("0.0022", dec.to_string());

pub fn trimmed_end(self) -> Self

Returns this number with its trailing zeros removed.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from(123400)
    .multiplied_pow10(-4)
    .padded_start(4);
assert_eq!("0012.3400", dec.to_string());

assert_eq!("0012.34", dec.trimmed_end().to_string());

pub fn trim_end(&mut self)

Removes the trailing zeros of this number.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(123400)
    .multiplied_pow10(-4)
    .padded_start(4);
assert_eq!("0012.3400", dec.to_string());

dec.trim_end();
assert_eq!("0012.34", dec.to_string());

There is no effect if the least significant digit has magnitude more than zero:

let mut dec = FixedDecimal::from(2200);
assert_eq!("2200", dec.to_string());

dec.trim_end();
assert_eq!("2200", dec.to_string());

pub fn padded_start(self, position: i16) -> Self

Returns this number padded with leading zeros on a particular position.

Negative position numbers have no effect.

Also see FixedDecimal::with_max_position().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(42);
assert_eq!("42", dec.to_string());
assert_eq!("0042", dec.clone().padded_start(4).to_string());

assert_eq!("042", dec.clone().padded_start(3).to_string());

assert_eq!("42", dec.clone().padded_start(2).to_string());

assert_eq!("42", dec.clone().padded_start(1).to_string());

pub fn pad_start(&mut self, position: i16)

Pads this number with leading zeros on a particular position.

Negative position numbers have no effect.

Also see FixedDecimal::set_max_position().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(42);
assert_eq!("42", dec.to_string());

dec.pad_start(4);
assert_eq!("0042", dec.to_string());

dec.pad_start(3);
assert_eq!("042", dec.to_string());

dec.pad_start(2);
assert_eq!("42", dec.to_string());

dec.pad_start(1);
assert_eq!("42", dec.to_string());

pub fn padded_end(self, position: i16) -> Self

Returns this number padded with trailing zeros on a particular (negative) position. Will truncate zeros if necessary, but will not truncate other digits.

Positive position numbers have no effect.

Also see FixedDecimal::trunced().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("123.456").unwrap();
assert_eq!("123.456", dec.to_string());

assert_eq!("123.456", dec.clone().padded_end(-1).to_string());

assert_eq!("123.456", dec.clone().padded_end(-2).to_string());

assert_eq!("123.456000", dec.clone().padded_end(-6).to_string());

assert_eq!("123.4560", dec.clone().padded_end(-4).to_string());

pub fn pad_end(&mut self, position: i16)

Pads this number with trailing zeros on a particular (non-positive) position. Will truncate trailing zeros if necessary, but will not truncate other digits.

Positive position numbers have no effect.

Also see FixedDecimal::trunc().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("123.456").unwrap();
assert_eq!("123.456", dec.to_string());

dec.pad_end(-2);
assert_eq!("123.456", dec.to_string());

dec.pad_end(-6);
assert_eq!("123.456000", dec.to_string());

let mut dec = FixedDecimal::from_str("123.000").unwrap();
dec.pad_end(0);
assert_eq!("123", dec.to_string());

pub fn with_max_position(self, position: i16) -> Self

Returns this number with the leading significant digits truncated to a particular position, deleting digits if necessary.

Also see FixedDecimal::padded_start().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(4235970).multiplied_pow10(-3);
assert_eq!("4235.970", dec.to_string());

assert_eq!("04235.970", dec.clone().with_max_position(5).to_string());

assert_eq!("35.970", dec.clone().with_max_position(2).to_string());

assert_eq!("5.970", dec.clone().with_max_position(1).to_string());

assert_eq!("0.970", dec.clone().with_max_position(0).to_string());

assert_eq!("0.070", dec.clone().with_max_position(-1).to_string());

assert_eq!("0.000", dec.clone().with_max_position(-2).to_string());

assert_eq!("0.0000", dec.clone().with_max_position(-4).to_string());

pub fn set_max_position(&mut self, position: i16)

Truncates the leading significant digits of this number to a particular position, deleting digits if necessary.

Also see FixedDecimal::pad_start().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from(4235970).multiplied_pow10(-3);
assert_eq!("4235.970", dec.to_string());

dec.set_max_position(5);
assert_eq!("04235.970", dec.to_string());

dec.set_max_position(2);
assert_eq!("35.970", dec.to_string());

dec.set_max_position(1);
assert_eq!("5.970", dec.to_string());

dec.set_max_position(0);
assert_eq!("0.970", dec.to_string());

dec.set_max_position(-1);
assert_eq!("0.070", dec.to_string());

dec.set_max_position(-2);
assert_eq!("0.000", dec.to_string());

dec.set_max_position(-4);
assert_eq!("0.0000", dec.to_string());

pub fn round(&mut self, position: i16)

Rounds this number at a particular digit position.

This uses half to even rounding, which rounds to the nearest integer and resolves ties by selecting the nearest even integer to the original value.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("-1.5").unwrap();
dec.round(0);
assert_eq!("-2", dec.to_string());
let mut dec = FixedDecimal::from_str("0.4").unwrap();
dec.round(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("0.5").unwrap();
dec.round(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("0.6").unwrap();
dec.round(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("1.5").unwrap();
dec.round(0);
assert_eq!("2", dec.to_string());

pub fn rounded(self, position: i16) -> Self

Returns this number rounded at a particular digit position.

This uses half to even rounding by default, which rounds to the nearest integer and resolves ties by selecting the nearest even integer to the original value.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("-1.5").unwrap();
assert_eq!("-2", dec.rounded(0).to_string());
let mut dec = FixedDecimal::from_str("0.4").unwrap();
assert_eq!("0", dec.rounded(0).to_string());
let mut dec = FixedDecimal::from_str("0.5").unwrap();
assert_eq!("0", dec.rounded(0).to_string());
let mut dec = FixedDecimal::from_str("0.6").unwrap();
assert_eq!("1", dec.rounded(0).to_string());
let mut dec = FixedDecimal::from_str("1.5").unwrap();
assert_eq!("2", dec.rounded(0).to_string());

pub fn ceil(&mut self, position: i16)

Rounds this number towards positive infinity at a particular digit position.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("-1.5").unwrap();
dec.ceil(0);
assert_eq!("-1", dec.to_string());
let mut dec = FixedDecimal::from_str("0.4").unwrap();
dec.ceil(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("0.5").unwrap();
dec.ceil(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("0.6").unwrap();
dec.ceil(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("1.5").unwrap();
dec.ceil(0);
assert_eq!("2", dec.to_string());

pub fn ceiled(self, position: i16) -> Self

Returns this number rounded towards positive infinity at a particular digit position.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from_str("-1.5").unwrap();
assert_eq!("-1", dec.ceiled(0).to_string());
let dec = FixedDecimal::from_str("0.4").unwrap();
assert_eq!("1", dec.ceiled(0).to_string());
let dec = FixedDecimal::from_str("0.5").unwrap();
assert_eq!("1", dec.ceiled(0).to_string());
let dec = FixedDecimal::from_str("0.6").unwrap();
assert_eq!("1", dec.ceiled(0).to_string());
let dec = FixedDecimal::from_str("1.5").unwrap();
assert_eq!("2", dec.ceiled(0).to_string());

pub fn expand(&mut self, position: i16)

Rounds this number away from zero at a particular digit position.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("-1.5").unwrap();
dec.expand(0);
assert_eq!("-2", dec.to_string());
let mut dec = FixedDecimal::from_str("0.4").unwrap();
dec.expand(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("0.5").unwrap();
dec.expand(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("0.6").unwrap();
dec.expand(0);
assert_eq!("1", dec.to_string());
let mut dec = FixedDecimal::from_str("1.5").unwrap();
dec.expand(0);
assert_eq!("2", dec.to_string());

pub fn expanded(self, position: i16) -> Self

Returns this number rounded away from zero at a particular digit position.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from_str("-1.5").unwrap();
assert_eq!("-2", dec.expanded(0).to_string());
let dec = FixedDecimal::from_str("0.4").unwrap();
assert_eq!("1", dec.expanded(0).to_string());
let dec = FixedDecimal::from_str("0.5").unwrap();
assert_eq!("1", dec.expanded(0).to_string());
let dec = FixedDecimal::from_str("0.6").unwrap();
assert_eq!("1", dec.expanded(0).to_string());
let dec = FixedDecimal::from_str("1.5").unwrap();
assert_eq!("2", dec.expanded(0).to_string());

pub fn floor(&mut self, position: i16)

Rounds this number towards negative infinity at a particular digit position.

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("-1.5").unwrap();
dec.floor(0);
assert_eq!("-2", dec.to_string());
let mut dec = FixedDecimal::from_str("0.4").unwrap();
dec.floor(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("0.5").unwrap();
dec.floor(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("0.6").unwrap();
dec.floor(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("1.5").unwrap();
dec.floor(0);
assert_eq!("1", dec.to_string());

pub fn floored(self, position: i16) -> Self

Returns this number rounded towards negative infinity at a particular digit position.

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from_str("-1.5").unwrap();
assert_eq!("-2", dec.floored(0).to_string());
let dec = FixedDecimal::from_str("0.4").unwrap();
assert_eq!("0", dec.floored(0).to_string());
let dec = FixedDecimal::from_str("0.5").unwrap();
assert_eq!("0", dec.floored(0).to_string());
let dec = FixedDecimal::from_str("0.6").unwrap();
assert_eq!("0", dec.floored(0).to_string());
let dec = FixedDecimal::from_str("1.5").unwrap();
assert_eq!("1", dec.floored(0).to_string());

pub fn trunc(&mut self, position: i16)

Rounds this number towards zero at a particular digit position.

Also see FixedDecimal::pad_end().

Examples

use fixed_decimal::FixedDecimal;

let mut dec = FixedDecimal::from_str("-1.5").unwrap();
dec.trunc(0);
assert_eq!("-1", dec.to_string());
let mut dec = FixedDecimal::from_str("0.4").unwrap();
dec.trunc(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("0.5").unwrap();
dec.trunc(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("0.6").unwrap();
dec.trunc(0);
assert_eq!("0", dec.to_string());
let mut dec = FixedDecimal::from_str("1.5").unwrap();
dec.trunc(0);
assert_eq!("1", dec.to_string());

pub fn trunced(self, position: i16) -> Self

Returns this number rounded towards zero at a particular digit position.

Also see FixedDecimal::padded_end().

Examples

use fixed_decimal::FixedDecimal;

let dec = FixedDecimal::from_str("-1.5").unwrap();
assert_eq!("-1", dec.trunced(0).to_string());
let dec = FixedDecimal::from_str("0.4").unwrap();
assert_eq!("0", dec.trunced(0).to_string());
let dec = FixedDecimal::from_str("0.5").unwrap();
assert_eq!("0", dec.trunced(0).to_string());
let dec = FixedDecimal::from_str("0.6").unwrap();
assert_eq!("0", dec.trunced(0).to_string());
let dec = FixedDecimal::from_str("1.5").unwrap();
assert_eq!("1", dec.trunced(0).to_string());

pub fn round_with_mode(&mut self, position: i16, mode: RoundingMode)

Rounds this number at a particular digit position, using the specified rounding mode.

Examples

use fixed_decimal::{FixedDecimal, RoundingMode};

let mut dec = FixedDecimal::from_str("-3.5").unwrap();
dec.round_with_mode(0, RoundingMode::Floor);
assert_eq!("-4", dec.to_string());
let mut dec = FixedDecimal::from_str("-3.5").unwrap();
dec.round_with_mode(0, RoundingMode::Ceil);
assert_eq!("-3", dec.to_string());
let mut dec = FixedDecimal::from_str("5.455").unwrap();
dec.round_with_mode(-2, RoundingMode::HalfExpand);
assert_eq!("5.46", dec.to_string());
let mut dec = FixedDecimal::from_str("-7.235").unwrap();
dec.round_with_mode(-2, RoundingMode::HalfTrunc);
assert_eq!("-7.23", dec.to_string());
let mut dec = FixedDecimal::from_str("9.75").unwrap();
dec.round_with_mode(-1, RoundingMode::HalfEven);
assert_eq!("9.8", dec.to_string());

pub fn rounded_with_mode(self, position: i16, mode: RoundingMode) -> Self

Returns this number rounded at a particular digit position, using the specified rounding mode.

Examples

use fixed_decimal::{FixedDecimal, RoundingMode};

let mut dec = FixedDecimal::from_str("-3.5").unwrap();
assert_eq!(
    "-4",
    dec.rounded_with_mode(0, RoundingMode::Floor).to_string()
);
let mut dec = FixedDecimal::from_str("-3.5").unwrap();
assert_eq!(
    "-3",
    dec.rounded_with_mode(0, RoundingMode::Ceil).to_string()
);
let mut dec = FixedDecimal::from_str("5.455").unwrap();
assert_eq!(
    "5.46",
    dec.rounded_with_mode(-2, RoundingMode::HalfExpand)
        .to_string()
);
let mut dec = FixedDecimal::from_str("-7.235").unwrap();
assert_eq!(
    "-7.23",
    dec.rounded_with_mode(-2, RoundingMode::HalfTrunc)
        .to_string()
);
let mut dec = FixedDecimal::from_str("9.75").unwrap();
assert_eq!(
    "9.8",
    dec.rounded_with_mode(-1, RoundingMode::HalfEven)
        .to_string()
);

pub fn round_with_mode_and_increment( &mut self, position: i16, mode: RoundingMode, increment: RoundingIncrement, )

Rounds this number at a particular digit position and increment, using the specified rounding mode.

Examples

use fixed_decimal::{FixedDecimal, RoundingIncrement, RoundingMode};

let mut dec = FixedDecimal::from_str("-3.5").unwrap();
dec.round_with_mode_and_increment(
    0,
    RoundingMode::Floor,
    RoundingIncrement::MultiplesOf1,
);
assert_eq!("-4", dec.to_string());
let mut dec = FixedDecimal::from_str("-3.59").unwrap();
dec.round_with_mode_and_increment(
    -1,
    RoundingMode::Ceil,
    RoundingIncrement::MultiplesOf2,
);
assert_eq!("-3.4", dec.to_string());
let mut dec = FixedDecimal::from_str("5.455").unwrap();
dec.round_with_mode_and_increment(
    -2,
    RoundingMode::HalfExpand,
    RoundingIncrement::MultiplesOf5,
);
assert_eq!("5.45", dec.to_string());
let mut dec = FixedDecimal::from_str("-7.235").unwrap();
dec.round_with_mode_and_increment(
    -2,
    RoundingMode::HalfTrunc,
    RoundingIncrement::MultiplesOf25,
);
assert_eq!("-7.25", dec.to_string());
let mut dec = FixedDecimal::from_str("9.75").unwrap();
dec.round_with_mode_and_increment(
    -1,
    RoundingMode::HalfEven,
    RoundingIncrement::MultiplesOf5,
);
assert_eq!("10.0", dec.to_string());

pub fn rounded_with_mode_and_increment( self, position: i16, mode: RoundingMode, increment: RoundingIncrement, ) -> Self

Returns this number rounded at a particular digit position and increment, using the specified rounding mode.

Examples

use fixed_decimal::{FixedDecimal, RoundingIncrement, RoundingMode};

let mut dec = FixedDecimal::from_str("-3.5").unwrap();
assert_eq!(
    "-4",
    dec.rounded_with_mode_and_increment(
        0,
        RoundingMode::Floor,
        RoundingIncrement::MultiplesOf1
    )
    .to_string()
);
let mut dec = FixedDecimal::from_str("-3.59").unwrap();
assert_eq!(
    "-3.4",
    dec.rounded_with_mode_and_increment(
        -1,
        RoundingMode::Ceil,
        RoundingIncrement::MultiplesOf2
    )
    .to_string()
);
let mut dec = FixedDecimal::from_str("5.455").unwrap();
assert_eq!(
    "5.45",
    dec.rounded_with_mode_and_increment(
        -2,
        RoundingMode::HalfExpand,
        RoundingIncrement::MultiplesOf5
    )
    .to_string()
);
let mut dec = FixedDecimal::from_str("-7.235").unwrap();
assert_eq!(
    "-7.25",
    dec.rounded_with_mode_and_increment(
        -2,
        RoundingMode::HalfTrunc,
        RoundingIncrement::MultiplesOf25
    )
    .to_string()
);
let mut dec = FixedDecimal::from_str("9.75").unwrap();
assert_eq!(
    "10.0",
    dec.rounded_with_mode_and_increment(
        -1,
        RoundingMode::HalfEven,
        RoundingIncrement::MultiplesOf5
    )
    .to_string()
);

pub fn concatenated_end( self, other: FixedDecimal, ) -> Result<Self, (FixedDecimal, FixedDecimal)>

Concatenate another FixedDecimal into the end of this FixedDecimal.

All nonzero digits in other must have lower magnitude than nonzero digits in self. If the two decimals represent overlapping ranges of magnitudes, an Err is returned, containing (self, other).

The magnitude range of self will be increased if other covers a larger range.

Examples

use fixed_decimal::FixedDecimal;

let integer = FixedDecimal::from(123);
let fraction = FixedDecimal::from(456).multiplied_pow10(-3);

let result = integer.concatenated_end(fraction).expect("nonoverlapping");

assert_eq!("123.456", result.to_string());

pub fn concatenate_end( &mut self, other: FixedDecimal, ) -> Result<(), FixedDecimal>

Concatenate another FixedDecimal into the end of this FixedDecimal.

All nonzero digits in other must have lower magnitude than nonzero digits in self. If the two decimals represent overlapping ranges of magnitudes, an Err is returned, passing ownership of other back to the caller.

The magnitude range of self will be increased if other covers a larger range.

Examples

use fixed_decimal::FixedDecimal;

let mut integer = FixedDecimal::from(123);
let fraction = FixedDecimal::from(456).multiplied_pow10(-3);

integer.concatenate_end(fraction);

assert_eq!("123.456", integer.to_string());

impl FixedDecimal

pub fn to_string(&self) -> String

Converts the given value to a String.

Under the hood, this uses an efficient [Writeable] implementation. However, in order to avoid allocating a string, it is more efficient to use [Writeable] directly.

impl FixedDecimal

pub fn try_from_str(s: &str) -> Result<Self, ParseError>

Parses a FixedDecimal.

pub fn try_from_utf8(input_str: &[u8]) -> Result<Self, ParseError>

impl FixedDecimal

pub fn try_from_f64( float: f64, precision: FloatPrecision, ) -> Result<Self, LimitError>

Constructs a FixedDecimal from an f64.

Since f64 values do not carry a notion of their precision, the second argument to this function specifies the type of precision associated with the f64. For more information, see FloatPrecision.

This function uses ryu, which is an efficient double-to-string algorithm, but other implementations may yield higher performance; for more details, see icu4x#166.

This function can be made available with the "ryu" Cargo feature.

use fixed_decimal::{FixedDecimal, FloatPrecision};
use writeable::assert_writeable_eq;

let decimal =
    FixedDecimal::try_from_f64(-5.1, FloatPrecision::Magnitude(-2))
        .expect("Finite quantity with limited precision");
assert_writeable_eq!(decimal, "-5.10");

let decimal =
    FixedDecimal::try_from_f64(0.012345678, FloatPrecision::RoundTrip)
        .expect("Finite quantity");
assert_writeable_eq!(decimal, "0.012345678");

let decimal =
    FixedDecimal::try_from_f64(12345678000., FloatPrecision::Integer)
        .expect("Finite, integer-valued quantity");
assert_writeable_eq!(decimal, "12345678000");

Negative zero is supported.

use fixed_decimal::{FixedDecimal, FloatPrecision};
use writeable::assert_writeable_eq;

// IEEE 754 for floating point defines the sign bit separate
// from the mantissa and exponent, allowing for -0.
let negative_zero =
    FixedDecimal::try_from_f64(-0.0, FloatPrecision::Integer)
        .expect("Negative zero");
assert_writeable_eq!(negative_zero, "-0");

Trait Implementations

impl Clone for FixedDecimal

fn clone(&self) -> FixedDecimal

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FixedDecimal

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

Formats the value using the given formatter.

impl Default for FixedDecimal

fn default() -> Self

Returns a FixedDecimal representing zero.

impl Display for FixedDecimal

This trait is implemented for compatibility with fmt!. To create a string, [Writeable::write_to_string] is usually more efficient.

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

Formats the value using the given formatter.

impl From<FixedInteger> for FixedDecimal

fn from(value: FixedInteger) -> Self

Converts to this type from the input type.

impl From<i128> for FixedDecimal

fn from(value: i128) -> Self

Converts to this type from the input type.

impl From<i16> for FixedDecimal

fn from(value: i16) -> Self

Converts to this type from the input type.

impl From<i32> for FixedDecimal

fn from(value: i32) -> Self

Converts to this type from the input type.

impl From<i64> for FixedDecimal

fn from(value: i64) -> Self

Converts to this type from the input type.

impl From<i8> for FixedDecimal

fn from(value: i8) -> Self

Converts to this type from the input type.

impl From<isize> for FixedDecimal

fn from(value: isize) -> Self

Converts to this type from the input type.

impl From<u128> for FixedDecimal

fn from(value: u128) -> Self

Converts to this type from the input type.

impl From<u16> for FixedDecimal

fn from(value: u16) -> Self

Converts to this type from the input type.

impl From<u32> for FixedDecimal

fn from(value: u32) -> Self

Converts to this type from the input type.

impl From<u64> for FixedDecimal

fn from(value: u64) -> Self

Converts to this type from the input type.

impl From<u8> for FixedDecimal

fn from(value: u8) -> Self

Converts to this type from the input type.

impl From<usize> for FixedDecimal

fn from(value: usize) -> Self

Converts to this type from the input type.

impl FromStr for FixedDecimal

type Err = ParseError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

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

impl PartialEq for FixedDecimal

fn eq(&self, other: &FixedDecimal) -> 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<FixedDecimal> for FixedInteger

type Error = LimitError

The type returned in the event of a conversion error.

fn try_from(value: FixedDecimal) -> Result<Self, Self::Error>

Performs the conversion.

impl Writeable for FixedDecimal

Render the FixedDecimal as a string of ASCII digits with a possible decimal point.

Examples

assert_writeable_eq!(FixedDecimal::from(42), "42");

fn write_to<W: Write + ?Sized>(&self, sink: &mut W) -> Result

Writes a string to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to_parts, and discards any Part annotations.

fn writeable_length_hint(&self) -> LengthHint

Returns a hint for the number of UTF-8 bytes that will be written to the sink.

fn write_to_parts<S>(&self, sink: &mut S) -> Result<(), Error>

where S: PartsWrite + ?Sized,

Write bytes and Part annotations to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to, and doesn’t produce any Part annotations.

fn write_to_string(&self) -> Cow<'_, str>

Creates a new String with the data from this Writeable. Like ToString, but smaller and faster.

impl StructuralPartialEq for FixedDecimal