GetIteratorFlattenable.js 1.4 KB

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  1. 'use strict';
  2. var $TypeError = require('es-errors/type');
  3. var isObject = require('es-object-atoms/isObject');
  4. var AdvanceStringIndex = require('./AdvanceStringIndex');
  5. var Call = require('./Call');
  6. var GetIteratorDirect = require('./GetIteratorDirect');
  7. var GetMethod = require('./GetMethod');
  8. var IsArray = require('./IsArray');
  9. var getIteratorMethod = require('../helpers/getIteratorMethod');
  10. // https://262.ecma-international.org/16.0/#sec-getiteratorflattenable
  11. module.exports = function GetIteratorFlattenable(obj, primitiveHandling) {
  12. if (primitiveHandling !== 'REJECT-PRIMITIVES' && primitiveHandling !== 'ITERATE-STRING-PRIMITIVES') {
  13. throw new $TypeError('Assertion failed: `stringHandling` must be "REJECT-PRIMITIVES" or "ITERATE-STRING-PRIMITIVES"');
  14. }
  15. if (!isObject(obj)) {
  16. if (primitiveHandling === 'REJECT-PRIMITIVES' || typeof obj !== 'string') {
  17. throw new $TypeError('obj must be an Object'); // step 1.a
  18. }
  19. }
  20. // var method = GetMethod(obj, Symbol.iterator); // step 2
  21. var method = getIteratorMethod(
  22. {
  23. AdvanceStringIndex: AdvanceStringIndex,
  24. GetMethod: GetMethod,
  25. IsArray: IsArray
  26. },
  27. obj
  28. );
  29. var iterator;
  30. if (typeof method === 'undefined') { // step 3
  31. iterator = obj; // step 3.a
  32. } else { // step 4
  33. iterator = Call(method, obj); // step 4.a
  34. }
  35. if (!isObject(iterator)) {
  36. throw new $TypeError('iterator must be an Object'); // step 5
  37. }
  38. return GetIteratorDirect(iterator); // step 6
  39. };