big-rat/lib/rationalize.js

A big integer rational number

'use strict'

var num2bn = require('./num-to-bn')
var sign = require('./bn-sign')

module.exports = rationalize

function rationalize(numer, denom) {
  var snumer = sign(numer)
  var sdenom = sign(denom)
  if(snumer === 0) {
    return [num2bn(0), num2bn(1)]
  }
  if(sdenom === 0) {
    return [num2bn(0), num2bn(0)]
  }
  if(sdenom < 0) {
    numer = numer.neg()
    denom = denom.neg()
  }
  var d = numer.gcd(denom)
  if(d.cmpn(1)) {
    return [ numer.div(d), denom.div(d) ]
  }
  return [ numer, denom ]
}