GroupBy.js 2.4 KB

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  1. 'use strict';
  2. var $TypeError = require('es-errors/type');
  3. var AddValueToKeyedGroup = require('./AddValueToKeyedGroup');
  4. var Call = require('./Call');
  5. var CanonicalizeKeyedCollectionKey = require('./CanonicalizeKeyedCollectionKey');
  6. var GetIterator = require('./GetIterator');
  7. var IfAbruptCloseIterator = require('./IfAbruptCloseIterator');
  8. var IsCallable = require('./IsCallable');
  9. var IteratorClose = require('./IteratorClose');
  10. var IteratorStep = require('./IteratorStep');
  11. var IteratorValue = require('./IteratorValue');
  12. var RequireObjectCoercible = require('./RequireObjectCoercible');
  13. var ThrowCompletion = require('./ThrowCompletion');
  14. var ToPropertyKey = require('./ToPropertyKey');
  15. var maxSafeInteger = require('../helpers/maxSafeInteger');
  16. // https://262.ecma-international.org/16.0/#sec-groupby
  17. module.exports = function GroupBy(items, callbackfn, keyCoercion) {
  18. if (keyCoercion !== 'PROPERTY' && keyCoercion !== 'COLLECTION') {
  19. throw new $TypeError('Assertion failed: `keyCoercion` must be `"PROPERTY"` or `"COLLECTION"`');
  20. }
  21. RequireObjectCoercible(items); // step 1
  22. if (!IsCallable(callbackfn)) {
  23. throw new $TypeError('callbackfn must be callable'); // step 2
  24. }
  25. var groups = []; // step 3
  26. var iteratorRecord = GetIterator(items, 'SYNC'); // step 4
  27. var k = 0; // step 5
  28. // eslint-disable-next-line no-constant-condition
  29. while (true) { // step 6
  30. if (k >= maxSafeInteger) { // step 6.a
  31. var error = ThrowCompletion(new $TypeError('k must be less than 2 ** 53 - 1')); // step 6.a.i
  32. return IteratorClose(iteratorRecord, error); // step 6.a.ii
  33. }
  34. var next = IteratorStep(iteratorRecord); // step 6.b
  35. if (!next) { // step 6.c
  36. return groups; // step 6.c.i
  37. }
  38. var value = IteratorValue(next); // step 6.dv
  39. var key;
  40. try {
  41. key = Call(callbackfn, undefined, [value, k]); // step 6.e
  42. } catch (e) {
  43. IfAbruptCloseIterator(ThrowCompletion(e), iteratorRecord); // step 6.f
  44. }
  45. if (keyCoercion === 'PROPERTY') { // step 6.g
  46. try {
  47. key = ToPropertyKey(key); // step 6.g.i
  48. } catch (e) {
  49. IfAbruptCloseIterator(ThrowCompletion(e), iteratorRecord); // step 6.g.ii
  50. }
  51. } else { // step 6.h
  52. if (keyCoercion !== 'COLLECTION') {
  53. throw new $TypeError('keyCoercion must be ~PROPERTY~ or ~COLLECTION~'); // step 6.h.i
  54. }
  55. key = CanonicalizeKeyedCollectionKey(key); // step 6.h.ii
  56. }
  57. AddValueToKeyedGroup(groups, key, value); // step 6.i
  58. k += 1; // step 6.j
  59. }
  60. };