n2words/src/mr-IN.js

Convert numbers to words in 70+ languages with zero dependencies. Supports BigInt, decimals, and browser/Node.js environments.

/**
 * Marathi (India) language converter
 *
 * CLDR: mr-IN | Marathi as used in India
 *
 * Key features:
 * - Indian numbering system (हजार, लाख, कोटी)
 * - Devanagari script
 * - 3-2-2 grouping pattern (last 3 digits, then groups of 2)
 * - Complete word forms for 0-99
 * - Per-digit decimal reading
 */

import { parseCardinalValue } from './utils/parse-cardinal.js'
import { parseCurrencyValue } from './utils/parse-currency.js'
import { parseOrdinalValue } from './utils/parse-ordinal.js'
import { checkMax } from './utils/check-max.js'
import { indian } from './utils/scale.js'

// ============================================================================
// Vocabulary
// ============================================================================

const ZERO = 'शून्य'
const NEGATIVE = 'उणे'
const DECIMAL_SEP = 'दशांश'
const HUNDRED = 'शंभर'

// ============================================================================
// Ordinal Vocabulary
// ============================================================================

// Ordinal suffix (adds to cardinal for numbers >= 7)
const ORDINAL_SUFFIX = 'वा'

// Special ordinals for first few numbers (1-6 have irregular forms)
const ORDINAL_SPECIAL = ['', 'पहिला', 'दुसरा', 'तिसरा', 'चौथा', 'पाचवा', 'सहावा']

// ============================================================================
// Currency Vocabulary (Indian Rupee)
// ============================================================================

// Rupee: singular/plural
const RUPEE = 'रुपया'
const RUPEES = 'रुपये'

// Paisa: singular/plural
const PAISA = 'पैसा'
const PAISE = 'पैसे'

const BELOW_HUNDRED = [
  'शून्य', 'एक', 'दोन', 'तीन', 'चार', 'पाच', 'सहा', 'सात', 'आठ', 'नऊ',
  'दहा', 'अकरा', 'बारा', 'तेरा', 'चौदा', 'पंधरा', 'सोळा', 'सतरा', 'अठरा', 'एकोणीस',
  'वीस', 'एकवीस', 'बावीस', 'तेवीस', 'चोवीस', 'पंचवीस', 'सव्वीस', 'सत्तावीस', 'अठ्ठावीस', 'एकोणतीस',
  'तीस', 'एकतीस', 'बत्तीस', 'तेहेतीस', 'चौतीस', 'पस्तीस', 'छत्तीस', 'सदतीस', 'अडतीस', 'एकोणचाळीस',
  'चाळीस', 'एकेचाळीस', 'बेचाळीस', 'त्रेचाळीस', 'चव्वेचाळीस', 'पंचेचाळीस', 'सेहेचाळीस', 'सत्तेचाळीस', 'अठ्ठेचाळीस', 'एकोणपन्नास',
  'पन्नास', 'एक्काव्वन', 'बावन्न', 'त्रेपन्न', 'चोपन्न', 'पंचाव्वन', 'छप्पन्न', 'सत्तावन्न', 'अठ्ठावन्न', 'एकोणसाठ',
  'साठ', 'एकसष्ठ', 'बासष्ठ', 'त्रेसष्ठ', 'चौसष्ठ', 'पासष्ठ', 'सहासष्ठ', 'सदुसष्ठ', 'अडुसष्ठ', 'एकोणसत्तर',
  'सत्तर', 'एकाहत्तर', 'बाहत्तर', 'त्र्याहत्तर', 'चौऱ्याहत्तर', 'पंच्याहत्तर', 'शहात्तर', 'सत्याहत्तर', 'अठ्ठ्याहत्तर', 'एकोणऐंशी',
  'ऐंशी', 'एक्याऐंशी', 'ब्याऐंशी', 'त्र्याऐंशी', 'चौऱ्याऐंशी', 'पंच्याऐंशी', 'शहाऐंशी', 'सत्याऐंशी', 'अठ्ठ्याऐंशी', 'एकोणनव्वद',
  'नव्वद', 'एक्याण्णव', 'ब्याण्णव', 'त्र्याण्णव', 'चौऱ्याण्णव', 'पंच्याण्णव', 'शहाण्णव', 'सत्याण्णव', 'अठ्ठ्याण्णव', 'नव्याण्णव',
]

// Scale words: index 0 = units (empty), 1 = thousand, 2 = lakh, 3 = crore, etc.
const SCALE_WORDS = ['', 'हजार', 'लाख', 'कोटी', 'अब्ज', 'खर्व', 'निखर्व', 'महापद्म', 'शंकू']

// 3-2-2 Indian grouping: a 3-digit base segment, then 2 digits per scale word
// (SCALE_WORDS[0] = '' is the units slot). Past the table the scale word is
// dropped, which collapses the magnitude — so cap there.
export const cardinalMax = indian(SCALE_WORDS.length)
export const ordinalMax = indian(SCALE_WORDS.length)
export const currencyMax = indian(SCALE_WORDS.length)

// ============================================================================
// Segment Building
// ============================================================================

/**
 * Builds words for a 0-999 segment.
 * @param {number} n - Segment value (0-999)
 * @returns {string} Marathi words for the segment
 */
function buildSegment(n) {
  if (n === 0) return ''
  if (n < 100) return BELOW_HUNDRED[n]

  const hundreds = Math.trunc(n / 100)
  const remainder = n % 100

  if (remainder === 0) {
    return BELOW_HUNDRED[hundreds] + ' ' + HUNDRED
  }
  return BELOW_HUNDRED[hundreds] + ' ' + HUNDRED + ' ' + BELOW_HUNDRED[remainder]
}

// ============================================================================
// Conversion Functions
// ============================================================================

/**
 * Converts a non-negative integer to Marathi words.
 *
 * Uses BigInt modulo for segment extraction (faster than string slicing).
 * South Asian 3-2-2 grouping: first 3 digits, then groups of 2.
 * @param {bigint} n - Non-negative integer to convert
 * @returns {string} Marathi words
 */
function integerToWords(n) {
  if (n === 0n) return ZERO

  // Fast path: numbers < 1000 (direct lookup)
  if (n < 1000n) {
    return buildSegment(Number(n))
  }

  // Extract segments using BigInt modulo
  const segments = []
  segments.push(Number(n % 1000n))
  let temp = n / 1000n

  while (temp > 0n) {
    segments.push(Number(temp % 100n))
    temp = temp / 100n
  }

  // Build result string (process from most-significant to least)
  const words = []
  for (let i = segments.length - 1; i >= 0; i--) {
    const segment = segments[i]
    if (segment === 0) continue

    if (i === 0) {
      words.push(buildSegment(segment))
    }
    else {
      words.push(BELOW_HUNDRED[segment])
    }

    if (i > 0 && SCALE_WORDS[i]) {
      words.push(SCALE_WORDS[i])
    }
  }

  return words.join(' ')
}

/**
 * Reads the fractional digits per-digit in Marathi.
 * @param {string} decimalPart - Decimal digit string
 * @returns {string} Marathi words for each digit
 */
function decimalPartToWords(decimalPart) {
  // Per-digit decimal reading
  const digits = []
  for (const char of decimalPart) {
    const d = parseInt(char, 10)
    digits.push(d === 0 ? ZERO : BELOW_HUNDRED[d])
  }
  return digits.join(' ')
}

/**
 * Converts a numeric value to Marathi words.
 * @param {number | string | bigint} value - The numeric value to convert
 * @returns {string} The number in Marathi words
 */
function toCardinal(value) {
  const { isNegative, integerPart, decimalPart } = parseCardinalValue(value)
  // The fraction is spelled digit by digit, so only the integer part has a ceiling.
  checkMax(integerPart, cardinalMax)

  let result = ''

  if (isNegative) {
    result = NEGATIVE + ' '
  }

  result += integerToWords(integerPart)

  if (decimalPart) {
    result += ' ' + DECIMAL_SEP + ' ' + decimalPartToWords(decimalPart)
  }

  return result
}

// ============================================================================
// ORDINAL: toOrdinal(value)
// ============================================================================

/**
 * Converts a positive integer to Marathi ordinal words.
 *
 * Marathi ordinals: First 6 are irregular, then add -वा suffix.
 * @param {bigint} n - Positive integer to convert
 * @returns {string} Marathi ordinal words
 */
function integerToOrdinal(n) {
  // Special ordinals for 1-6
  if (n >= 1n && n <= 6n) {
    return ORDINAL_SPECIAL[Number(n)]
  }

  // For 7 and above, add suffix to cardinal
  const cardinal = integerToWords(n)
  return cardinal + ORDINAL_SUFFIX
}

/**
 * Converts a numeric value to Marathi ordinal words.
 * @param {number | string | bigint} value - The numeric value to convert (positive integer)
 * @returns {string} The number as ordinal words
 * @throws {TypeError} If value is not a valid numeric type
 * @throws {RangeError} If value is negative, zero, or has a decimal part
 * @example
 * toOrdinal(1)    // 'पहिला'
 * toOrdinal(2)    // 'दुसरा'
 * toOrdinal(3)    // 'तिसरा'
 * toOrdinal(10)   // 'दहावा'
 */
function toOrdinal(value) {
  const integerPart = parseOrdinalValue(value)
  // Ordinals build on the cardinal speller, so they share its ceiling.
  checkMax(integerPart, ordinalMax)
  return integerToOrdinal(integerPart)
}

// ============================================================================
// CURRENCY: toCurrency(value, options?)
// ============================================================================

/**
 * Converts a numeric value to Marathi currency words (Indian Rupee).
 * @param {number | string | bigint} value - The currency amount to convert
 * @returns {string} The amount in Marathi currency words
 * @throws {TypeError} If value is not a valid numeric type
 * @throws {Error} If value is not a valid number format
 * @example
 * toCurrency(42.50)  // 'बेचाळीस रुपये पन्नास पैसे'
 * toCurrency(1)      // 'एक रुपया'
 * toCurrency(0.01)   // 'एक पैसा'
 */
function toCurrency(value) {
  const { isNegative, dollars: rupees, cents: paise } = parseCurrencyValue(value)
  checkMax(rupees, currencyMax)

  // Build result
  let result = ''
  if (isNegative) result = NEGATIVE + ' '

  // Rupees part - show if non-zero, or if no paise
  if (rupees > 0n || paise === 0n) {
    result += integerToWords(rupees)
    // Singular for 1 rupee, plural otherwise
    result += ' ' + (rupees === 1n ? RUPEE : RUPEES)
  }

  // Paise part
  if (paise > 0n) {
    if (rupees > 0n) {
      result += ' '
    }
    result += integerToWords(paise)
    // Singular for 1 paisa, plural otherwise
    result += ' ' + (paise === 1n ? PAISA : PAISE)
  }

  return result
}

// ============================================================================
// Exports
// ============================================================================

export { toCardinal, toOrdinal, toCurrency }