NumericToRawBytes.js 2.1 KB

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  1. 'use strict';
  2. var $TypeError = require('es-errors/type');
  3. var hasOwnProperty = require('./HasOwnProperty');
  4. var ToBigInt64 = require('./ToBigInt64');
  5. var ToBigUint64 = require('./ToBigUint64');
  6. var ToInt16 = require('./ToInt16');
  7. var ToInt32 = require('./ToInt32');
  8. var ToInt8 = require('./ToInt8');
  9. var ToUint16 = require('./ToUint16');
  10. var ToUint32 = require('./ToUint32');
  11. var ToUint8 = require('./ToUint8');
  12. var ToUint8Clamp = require('./ToUint8Clamp');
  13. var valueToFloat32Bytes = require('../helpers/valueToFloat32Bytes');
  14. var valueToFloat64Bytes = require('../helpers/valueToFloat64Bytes');
  15. var integerToNBytes = require('../helpers/integerToNBytes');
  16. var keys = require('object-keys');
  17. // https://262.ecma-international.org/11.0/#table-the-typedarray-constructors
  18. var TypeToSizes = {
  19. __proto__: null,
  20. Int8: 1,
  21. Uint8: 1,
  22. Uint8C: 1,
  23. Int16: 2,
  24. Uint16: 2,
  25. Int32: 4,
  26. Uint32: 4,
  27. BigInt64: 8,
  28. BigUint64: 8,
  29. Float32: 4,
  30. Float64: 8
  31. };
  32. var TypeToAO = {
  33. __proto__: null,
  34. Int8: ToInt8,
  35. Uint8: ToUint8,
  36. Uint8C: ToUint8Clamp,
  37. Int16: ToInt16,
  38. Uint16: ToUint16,
  39. Int32: ToInt32,
  40. Uint32: ToUint32,
  41. BigInt64: ToBigInt64,
  42. BigUint64: ToBigUint64
  43. };
  44. // https://262.ecma-international.org/11.0/#sec-numerictorawbytes
  45. module.exports = function NumericToRawBytes(type, value, isLittleEndian) {
  46. if (typeof type !== 'string' || !hasOwnProperty(TypeToSizes, type)) {
  47. throw new $TypeError('Assertion failed: `type` must be a TypedArray element type: ' + keys(TypeToSizes));
  48. }
  49. if (typeof value !== 'number' && typeof value !== 'bigint') {
  50. throw new $TypeError('Assertion failed: `value` must be a Number or a BigInt');
  51. }
  52. if (typeof isLittleEndian !== 'boolean') {
  53. throw new $TypeError('Assertion failed: `isLittleEndian` must be a Boolean');
  54. }
  55. if (type === 'Float32') { // step 1
  56. return valueToFloat32Bytes(value, isLittleEndian);
  57. } else if (type === 'Float64') { // step 2
  58. return valueToFloat64Bytes(value, isLittleEndian);
  59. } // step 3
  60. var n = TypeToSizes[type]; // step 3.a
  61. var convOp = TypeToAO[type]; // step 3.b
  62. var intValue = convOp(value); // step 3.c
  63. return integerToNBytes(intValue, n, isLittleEndian); // step 3.d, 3.e, 4
  64. };