FixedPoint64

ferum_std::fixed_point_64

Ferum's implementation of a FixedPoint number. Has fixed decimal places of 10 and a max value of MAX_U64 (18446744073709551615).

Operations that result in an overflow will error out.

Quick Example

use ferum_std::fixed_point_64::{Self, FixedPoint64};

/// Create fixed points from input.
let a = fixed_point_64::from_u64(1024, 3); // 1.024
let b = fixed_point_64::from_u64(2056, 2); // 20.56

// Compare two numbers
assert!(fixed_point_64::lte(a, b), 0);
assert!(!fixed_point_64::gte(a, b), 0);

// Get min/max of two fixed points.
let min = fixed_point_64::min(a, b);
let max = fixed_point_64::max(a, b);

// Perform addition / subtraction.
let added =  fixed_point_64::add(a, b);
let subtracted = fixed_point_64::sub(b, a);

// Perform multiplication / division with support for rounding up or truncating.
let multipliedRounded = fixed_point_64::multiply_round_up(a, a);
let multipliedTruncated = fixed_point_64::multiply_trunc(a, a);
let dividedRounded = fixed_point_64::divide_round_up(b, a);
let dividedTruncated = fixed_point_64::divide_trunc(b, a);

// Convert back to integers.
let au64 = fixed_point_64::to_u64(a, 3);
let bu64 = fixed_point_64::to_u64(b, 2);

Struct FixedPoint64

Fixedpoint struct. Can be stored, copied, and dropped.

struct FixedPoint64 has copy, drop, store

Constants

DECIMAL_PLACES

Number of decimal places in a FixedPoint value.

const DECIMAL_PLACES: u8 = 10;

ERR_EXCEED_MAX

Thrown when the value of a FixedPoint64 exceeds the max value able to be represented.

const ERR_EXCEED_MAX: u64 = 4;

ERR_EXCEED_MAX_DECIMALS

Thrown when max decimals of FixedPoint64 is exceeded. Possible examples:

  • if trying to create a FixedPoint64 from a 12 decimal number

  • if multiplying two 6 decimal numbers together

const ERR_EXCEED_MAX_DECIMALS: u64 = 1;

ERR_EXCEED_MAX_EXP

Because move doesn't have a native power function, we need to hardcode powers of 10. Thrown if we try to get a power of 10 that is not hardcoded.

const ERR_EXCEED_MAX_EXP: u64 = 2;

ERR_PRECISION_LOSS

Thrown when decimals are lost and not truncating or rounding up. Possible examples:

  • calling to_u64() to convert a number that has 6 decimal places into 5 decimal places, losing a digit

  • Dividing a number with 10 decimal places by 0.01, exceeding the max decimal places FixedPoint64 can represent.

const ERR_PRECISION_LOSS: u64 = 3;

MAX_VALUE

Max value a FixedPoint can represent.

const MAX_VALUE: u128 = 18446744073709551615;

Functions

Function new_u64

Create a new FixedPoint from a u64 value. No conversion is performed. Example: new_u64(12345) == 0.0000012345

public fun new_u64(val: u64): fixed_point_64::FixedPoint64

Function new_u128

Create a new FixedPoint from a u128 value. No conversion is performed. Example: new_u128(12345) == 0.0000012345

public fun new_u128(val: u128): fixed_point_64::FixedPoint64

Function value

Returns the underlying value of the FixedPoint.

public fun value(a: fixed_point_64::FixedPoint64): u128

Function zero

Return a FixedPoint that equals 0.

public fun zero(): fixed_point_64::FixedPoint64

Function one

Return a FixedPoint that equals 1.

public fun one(): fixed_point_64::FixedPoint64

Function half

Return a FixedPoint that equals 0.5.

public fun half(): fixed_point_64::FixedPoint64

Function max_fp

Returns the max FixedPoint value.

public fun max_fp(): fixed_point_64::FixedPoint64

Function min_fp

Returns the min FixedPoint value.

public fun min_fp(): fixed_point_64::FixedPoint64

Function trunc_to_decimals

Returns a FixedPoint truncated to the given decimal places.

public fun trunc_to_decimals(a: fixed_point_64::FixedPoint64, decimals: u8): fixed_point_64::FixedPoint64

Function round_up_to_decimals

Returns a FixedPoint rounded up to the given decimal places.

public fun round_up_to_decimals(a: fixed_point_64::FixedPoint64, decimals: u8): fixed_point_64::FixedPoint64

Function to_u64_trunc

Converts the FixedPoint to a u64 value with the given number of decimal places. Truncates any digits that are lost.

public fun to_u64_trunc(a: fixed_point_64::FixedPoint64, decimals: u8): u64

Function to_u128_trunc

Converts the FixedPoint to a u128 value with the given number of decimal places. Truncates any digits that are lost.

public fun to_u128_trunc(a: fixed_point_64::FixedPoint64, decimals: u8): u64

Function to_u64_round_up

Converts the FixedPoint to a u64 value with the given number of decimal places. Rounds up if digits are lost.

public fun to_u64_round_up(a: fixed_point_64::FixedPoint64, decimals: u8): u64

Function to_u128_round_up

Converts the FixedPoint to a u128 value with the given number of decimal places. Rounds up if digits are lost.

public fun to_u128_round_up(a: fixed_point_64::FixedPoint64, decimals: u8): u64

Function to_u64

Converts the FixedPoint to a u64 value with the given number of decimal places. Errors if any digits are lost.

public fun to_u64(a: fixed_point_64::FixedPoint64, decimals: u8): u64

Function to_u128

Converts the FixedPoint to a u128 value with the given number of decimal places. Errors if any digits are lost.

public fun to_u128(a: fixed_point_64::FixedPoint64, decimals: u8): u64

Function from_u64

Converts the value with the specified decimal places to a FixedPoint value.

public fun from_u64(v: u64, decimals: u8): fixed_point_64::FixedPoint64

Function from_u128

Converts the value with the specified decimal places to a FixedPoint value.

public fun from_u128(v: u128, decimals: u8): fixed_point_64::FixedPoint64

Function multiply_trunc

Multiplies two FixedPoints, truncating if the number of decimal places exceeds DECIMAL_PLACES.

public fun multiply_trunc(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function multiply_round_up

Multiplies two FixedPoints, rounding up if the number of decimal places exceeds DECIMAL_PLACES.

public fun multiply_round_up(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function divide_trunc

Divides two FixedPoints, truncating if the number of decimal places exceeds DECIMAL_PLACES.

public fun divide_trunc(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function divide_round_up

Divides two FixedPoints, rounding up if the number of decimal places exceeds DECIMAL_PLACES.

public fun divide_round_up(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function sqrt_approx

Returns the approximation of the square root of the FixedPoint using the Babylonian method. The approximation will always be less then the actual square root.

public fun sqrt_approx(v: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function add

Adds two FixedPoints.

public fun add(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function sub

Subtracts two FixedPoints.

public fun sub(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function lt

Return true if a < b.

public fun lt(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): bool

Function lte

Return true if a <= b.

public fun lte(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): bool

Function gt

Return true if a > b.

public fun gt(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): bool

Function gte

Return true if a >= b.

public fun gte(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): bool

Function eq

Return true if a == b.

public fun eq(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): bool

Function is_zero

Return true if the value is zero.

public fun is_zero(a: fixed_point_64::FixedPoint64): bool

Function max

Returns max(a, b).

public fun max(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64

Function min

Returns min(a, b).

public fun min(a: fixed_point_64::FixedPoint64, b: fixed_point_64::FixedPoint64): fixed_point_64::FixedPoint64
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