API index

The package exports every item below as a named export. Its default export is an object containing the seven classes and seven parsing functions.

Classes

Export	Constructor
Integer	new Integer(value)
Rational	new Rational(numerator, denominator?)
RationalInterval	new RationalInterval(a, b)
Fraction	new Fraction(numerator, denominator?, options?)
FractionInterval	new FractionInterval(a, b)
BaseSystem	new BaseSystem(characters, name?)
TypePromotion	Static utility class; do not instantiate

Parsing functions

Export	Signature
parseNumber	(value: string) => Integer \| Rational \| RationalInterval
parseRational	(value: string) => Rational
parseDecimal	(value: string) => Rational
parseRepeatingDecimal	(value: string) => Rational
parseMixedNumber	(value: string) => Rational
parseContinuedFraction	(value: string \| readonly (number \| bigint)[]) => Rational
parseInterval	(value: string) => RationalInterval

TypeScript types

type IntegerInput = number | string | bigint | Integer;
type RationalInput = IntegerInput | Rational;
type CoreScalar = Integer | Rational;
type CoreNumber = CoreScalar | RationalInterval;
type SternBrocotDirection = "L" | "R";

The formatting result interfaces are:

interface RepeatingExpansion {
  decimal: string;
  period: number;
}

interface BaseExpansion {
  baseStr: string;
  period: number;
  limitHit: boolean;
}

interface DecimalMetadata {
  wholePart?: bigint;
  initialSegment: string;
  initialSegmentLeadingZeros?: number;
  initialSegmentRest?: string;
  periodDigits: string;
  periodLength: number;
  leadingZerosInPeriod?: number;
  periodDigitsRest?: string;
  isTerminating: boolean;
}

Method checklist

This is a compact inventory; the linked class pages document behavior, examples, edge cases, and return types.

Class	Public members
Integer	value; add, subtract, multiply, divide, modulo, negate, pow; comparisons; abs, sign, sign/parity predicates; gcd, lcm; toString, toBase, toNumber, toRational; E, factorial, doubleFactorial, bitLength; static zero, one, from, fromRational
Rational	numerator, denominator; arithmetic, comparison, abs; fraction/mixed/decimal/base/scientific formatters; period metadata; continued-fraction conversion and convergents; E, bitLength; static construction helpers and formatting limits
RationalInterval	start, end, isAscending, low, high; arithmetic, pow, mpow; containment/set operations; interval formatters; mediant, midpoint, shortestDecimal, randomRational, E, bitLength; static zero, one, unitInterval, point, fromString
Fraction	numerator, denominator, isInfinite; unreduced arithmetic, comparisons, scale, reduce, E; mediant/Farey operations; Stern–Brocot navigation; static conversion and relationship helpers
FractionInterval	low, high; mediantSplit, partitionWithMediants, partitionWith; conversion, string/equality, E; static fromRationalInterval
BaseSystem	base, characters, charMap, name; digit conversion/validation; equality/case behavior; presets, factories, and prefix registry
TypePromotion	Type-level inspection/promotion; arithmetic dispatch; power, E notation, negation; syntactic type classification

The installed package’s index.d.ts is the authoritative machine-readable signature reference.