NumberToRawBytes.js 1.8 KB

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  1. 'use strict';
  2. var $TypeError = require('es-errors/type');
  3. var hasOwnProperty = require('./HasOwnProperty');
  4. var ToInt16 = require('./ToInt16');
  5. var ToInt32 = require('./ToInt32');
  6. var ToInt8 = require('./ToInt8');
  7. var ToUint16 = require('./ToUint16');
  8. var ToUint32 = require('./ToUint32');
  9. var ToUint8 = require('./ToUint8');
  10. var ToUint8Clamp = require('./ToUint8Clamp');
  11. var valueToFloat32Bytes = require('../helpers/valueToFloat32Bytes');
  12. var valueToFloat64Bytes = require('../helpers/valueToFloat64Bytes');
  13. var integerToNBytes = require('../helpers/integerToNBytes');
  14. var tableTAO = require('./tables/typed-array-objects');
  15. // https://262.ecma-international.org/8.0/#table-50
  16. var TypeToAO = {
  17. __proto__: null,
  18. $Int8: ToInt8,
  19. $Uint8: ToUint8,
  20. $Uint8C: ToUint8Clamp,
  21. $Int16: ToInt16,
  22. $Uint16: ToUint16,
  23. $Int32: ToInt32,
  24. $Uint32: ToUint32
  25. };
  26. // https://262.ecma-international.org/8.0/#sec-numbertorawbytes
  27. module.exports = function NumberToRawBytes(type, value, isLittleEndian) {
  28. if (typeof type !== 'string' || !hasOwnProperty(tableTAO.size, '$' + type)) {
  29. throw new $TypeError('Assertion failed: `type` must be a TypedArray element type');
  30. }
  31. if (typeof value !== 'number') {
  32. throw new $TypeError('Assertion failed: `value` must be a Number');
  33. }
  34. if (typeof isLittleEndian !== 'boolean') {
  35. throw new $TypeError('Assertion failed: `isLittleEndian` must be a Boolean');
  36. }
  37. if (type === 'Float32') { // step 1
  38. return valueToFloat32Bytes(value, isLittleEndian);
  39. } else if (type === 'Float64') { // step 2
  40. return valueToFloat64Bytes(value, isLittleEndian);
  41. } // step 3
  42. var n = tableTAO.size['$' + type]; // step 3.a
  43. var convOp = TypeToAO['$' + type]; // step 3.b
  44. var intValue = convOp(value); // step 3.c
  45. return integerToNBytes(intValue, n, isLittleEndian); // step 3.d, 3.e, 4
  46. };