Precise class

Precise represents an arbitrary precision number.

It can be used anywhere a Real Number is used.

Arbitrary precision can be used to combat the effects of cumulative rounding errors in circumstances where those errors can be significant.

This class enables arbitrary precision calculations in both Dart and when transpiled to JavaScript by representing numbers as digits that stay within the limitations of the underlying number system.

In JavaScript the maximum value of a number, because they are 64-bit floating point values, is 2^53, or 9007199254740992, and the maximum number of significant digits as a result is 16.

Inheritance

• Object
• Number
• Real
• Precise

Constructors

Precise(String value, {int sigDigits = 50})

Constructs an arbitrary precision number from a string.

Precise.fromMap(Map<String, String>? m)

Constructs a Precise number, applying the values found in map m. See toJson for the expected format.

factory

Precise.num(num value, {int? sigDigits})

Constructs a Precise number equal to value. The number of significant digits defaults to 19 for integers and 15 for doubles but may be specified.

factory

Precise.raw(List<Digit> digits, {int power = 0, bool neg = false, int sigDigits = 50})

Creates a arbitrary precision number directly from digits.

Properties

decimalPortion → Precise

Return only the decimal portion as a Precise number.

no setter

digits → List<Digit>

Returns a copy of the internal digits list, from least significant to most.

no setter

hashCode → int

If an integer value, returns the same hash as an int with the same value. If not an integer value, uses the hashing utility from the quiver package to create a high quality hash based on the digits, sign and power.

no setter, override

isFinite → bool

Whether this Number represents a finite value.

no setter, inherited

isInfinite → bool

Whether this Number represents infinity.

no setter, inherited

isInteger → bool

Returns true if the stored value can be represented exactly as an integer.

no setter, override

isNaN → bool

Whether this Number represents a value .

no setter, inherited

isNegative → bool

Whether this number is less than zero.

no setter, override

power → int

The offset of the decimal point.

no setter

precision ↔ int

Optional precision cutoff (maximum number of significant digits allowed).

getter/setter pair

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

sign → num

Returns minus one, zero or plus one depending on the sign and numerical value of the number. Returns minus one if the number is less than zero, plus one if the number is greater than zero, and zero if the number is equal to zero. Returns NaN if the number is NaN. Returns an int if this Number's value is an integer, a double otherwise.

no setter, inherited

value → num

All Real subclasses must be able to provide their value as a dart:core num.

no setter, override

Methods

abs() → Precise

Returns the absolute value of this Number.

override

ceil() → Precise

Returns the least Number having integer components no smaller than this Number.

override

clamp(dynamic lowerLimit, dynamic upperLimit) → Precise

Returns this num clamped to be in the range lowerLimit-upperLimit. The comparison is done using compareTo and therefore takes -0.0 into account. This also implies that double.NAN is treated as the maximal double value. lowerLimit and upperLimit are expected to be num or `Number' objects.

override

compareTo(dynamic n2) → int

Compares this Number to another Number by comparing values. n2 is expected to be a num or Number. If it is not it will be considered to have a value of 0.

inherited

digitAtPlace(int place) → Digit

Returns the digit at place, where place is with respect to the decimal number system (that is, place 1 is tens, place 2 is hundreds, place -3 is thousandths, etc).

floor() → Precise

Returns the greatest Number with an integer value no greater than this Number. If this is not finite (NaN or infinity), throws an UnsupportedError.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

reciprocal() → Number

Returns the Number that is the reciprocal of this Number. This Number is unaffected.

override

remainder(dynamic divisor) → Precise

Returns the remainder of the truncating division of this Number by divisor. The result r of this operation satisfies: this == (this ~/ other) * other + r. As a consequence the remainder r has the same sign as the operator /(divisor).

override

round() → Precise

Returns the Precise integer value closest to this Precise value. Rounds away from zero when there is no closest integer: (3.5).round() == 4 and (-3.5).round() == -4.

override

toDouble() → double

Converts this Number to a dart:core double.

override

toInt() → int

Converts this Number to a dart:core int.

override

toJson() → Map<String, dynamic>

Support dart:json stringify.

override

toString() → String

A string representation of this object.

override

truncate() → Precise

Returns a truncated value.

override

Operators

operator %(dynamic divisor) → Number

Modulo operator.

override

operator *(dynamic multiplier) → Precise

Multiplication operator. The precision of the product is the lesser of the precision of the two numbers so as not to imply a level of accuracy not present in the inputs.

override

operator +(dynamic addend) → Precise

Addition operator. The precision of the product is the lesser of the precision of the two numbers so as not to imply a level of accuracy not present in the inputs.

override

operator -(dynamic subtrahend) → Precise

Subtraction operator. The precision of the difference is the lesser of the precision of the two numbers so as not to imply a level of accuracy not present in the inputs.

override

operator /(dynamic divisor) → Number

Division operator. The precision of the product is the lesser of the precision of the two numbers so as not to imply a level of accuracy not present in the inputs.

override

operator <(dynamic other) → bool

Less than operator.

override

operator <=(dynamic other) → bool

Less than or equals operator.

override

operator ==(dynamic other) → bool

Equals operator.

override

operator >(dynamic other) → bool

Greater than operator.

override

operator >=(dynamic other) → bool

Greater than or equals operator.

override

operator ^(dynamic exponent) → Number

Power operator.

override

operator unary-() → Precise

Negation operator.

override

operator ~/(dynamic divisor) → Number

Truncating division operator.

override

Static Properties

one → Precise

One as a Precise number.

final

zero → Precise

Zero as a Precise number.

final

Static Methods

determinePlaceExtents(Precise p1, Precise p2) → List<int>

Returns the minimum and maximum place extents for the combination of two Precise objects, p1 and p2.

toPrecise(dynamic obj, {int? desiredPrecision}) → Precise

Converts a num, Number or String into a Precise object. int and Integer precision defaults to 19. double and Double precision defaults to 15. Any other kind of object defaults to 50. The precision parameter can override these defaults. If obj is a Precise object, a copy will be returned and its precision will be transferred unless overridden.