| 'use strict'; |
| |
| var GetIntrinsic = require('get-intrinsic'); |
| |
| var $Number = GetIntrinsic('%Number%'); |
| var $TypeError = GetIntrinsic('%TypeError%'); |
| |
| var $isNaN = require('../helpers/isNaN'); |
| var $isFinite = require('../helpers/isFinite'); |
| |
| var IsStringPrefix = require('./IsStringPrefix'); |
| var ToNumber = require('./ToNumber'); |
| var ToPrimitive = require('./ToPrimitive'); |
| var Type = require('./Type'); |
| |
| // https://262.ecma-international.org/9.0/#sec-abstract-relational-comparison |
| |
| module.exports = function AbstractRelationalComparison(x, y, LeftFirst) { |
| if (Type(LeftFirst) !== 'Boolean') { |
| throw new $TypeError('Assertion failed: LeftFirst argument must be a Boolean'); |
| } |
| var px; |
| var py; |
| if (LeftFirst) { |
| px = ToPrimitive(x, $Number); |
| py = ToPrimitive(y, $Number); |
| } else { |
| py = ToPrimitive(y, $Number); |
| px = ToPrimitive(x, $Number); |
| } |
| if (Type(px) === 'String' && Type(py) === 'String') { |
| if (IsStringPrefix(py, px)) { |
| return false; |
| } |
| if (IsStringPrefix(px, py)) { |
| return true; |
| } |
| return px < py; // both strings, neither a prefix of the other. shortcut for steps 3 c-f |
| } |
| var nx = ToNumber(px); |
| var ny = ToNumber(py); |
| if ($isNaN(nx) || $isNaN(ny)) { |
| return undefined; |
| } |
| if ($isFinite(nx) && $isFinite(ny) && nx === ny) { |
| return false; |
| } |
| if (nx === Infinity) { |
| return false; |
| } |
| if (ny === Infinity) { |
| return true; |
| } |
| if (ny === -Infinity) { |
| return false; |
| } |
| if (nx === -Infinity) { |
| return true; |
| } |
| return nx < ny; // by now, these are both nonzero, finite, and not equal |
| }; |