RawBytesToNumeric.js 2.4 KB

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  1. 'use strict';
  2. var GetIntrinsic = require('get-intrinsic');
  3. var callBound = require('call-bound');
  4. var $RangeError = require('es-errors/range');
  5. var $SyntaxError = require('es-errors/syntax');
  6. var $TypeError = require('es-errors/type');
  7. var $BigInt = GetIntrinsic('%BigInt%', true);
  8. var hasOwnProperty = require('./HasOwnProperty');
  9. var IsArray = require('./IsArray');
  10. var IsBigIntElementType = require('./IsBigIntElementType');
  11. var IsUnsignedElementType = require('./IsUnsignedElementType');
  12. var bytesAsFloat16 = require('../helpers/bytesAsFloat16');
  13. var bytesAsFloat32 = require('../helpers/bytesAsFloat32');
  14. var bytesAsFloat64 = require('../helpers/bytesAsFloat64');
  15. var bytesAsInteger = require('../helpers/bytesAsInteger');
  16. var every = require('../helpers/every');
  17. var isByteValue = require('../helpers/isByteValue');
  18. var $reverse = callBound('Array.prototype.reverse');
  19. var $slice = callBound('Array.prototype.slice');
  20. var tableTAO = require('./tables/typed-array-objects');
  21. // https://262.ecma-international.org/15.0/#sec-rawbytestonumeric
  22. module.exports = function RawBytesToNumeric(type, rawBytes, isLittleEndian) {
  23. if (!hasOwnProperty(tableTAO.size, '$' + type)) {
  24. throw new $TypeError('Assertion failed: `type` must be a TypedArray element type');
  25. }
  26. if (!IsArray(rawBytes) || !every(rawBytes, isByteValue)) {
  27. throw new $TypeError('Assertion failed: `rawBytes` must be an Array of bytes');
  28. }
  29. if (typeof isLittleEndian !== 'boolean') {
  30. throw new $TypeError('Assertion failed: `isLittleEndian` must be a Boolean');
  31. }
  32. var elementSize = tableTAO.size['$' + type]; // step 1
  33. if (rawBytes.length !== elementSize) {
  34. // this assertion is not in the spec, but it'd be an editorial error if it were ever violated
  35. throw new $RangeError('Assertion failed: `rawBytes` must have a length of ' + elementSize + ' for type ' + type);
  36. }
  37. var isBigInt = IsBigIntElementType(type);
  38. if (isBigInt && !$BigInt) {
  39. throw new $SyntaxError('this environment does not support BigInts');
  40. }
  41. // eslint-disable-next-line no-param-reassign
  42. rawBytes = $slice(rawBytes, 0, elementSize);
  43. if (!isLittleEndian) {
  44. $reverse(rawBytes); // step 2
  45. }
  46. if (type === 'FLOAT16') { // step 3
  47. return bytesAsFloat16(rawBytes);
  48. }
  49. if (type === 'FLOAT32') { // step 4
  50. return bytesAsFloat32(rawBytes);
  51. }
  52. if (type === 'FLOAT64') { // step 5
  53. return bytesAsFloat64(rawBytes);
  54. }
  55. return bytesAsInteger(rawBytes, elementSize, IsUnsignedElementType(type), isBigInt);
  56. };