esnext.uint8-array.from-hex.js 1.1 KB

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var global = require('../internals/global');
  4. var uncurryThis = require('../internals/function-uncurry-this');
  5. var aString = require('../internals/a-string');
  6. var Uint8Array = global.Uint8Array;
  7. var SyntaxError = global.SyntaxError;
  8. var parseInt = global.parseInt;
  9. var NOT_HEX = /[^\da-f]/i;
  10. var exec = uncurryThis(NOT_HEX.exec);
  11. var stringSlice = uncurryThis(''.slice);
  12. // `Uint8Array.fromHex` method
  13. // https://github.com/tc39/proposal-arraybuffer-base64
  14. if (Uint8Array) $({ target: 'Uint8Array', stat: true, forced: true }, {
  15. fromHex: function fromHex(string) {
  16. aString(string);
  17. var stringLength = string.length;
  18. if (stringLength % 2) throw new SyntaxError('String should have an even number of characters');
  19. if (exec(NOT_HEX, string)) throw new SyntaxError('String should only contain hex characters');
  20. var result = new Uint8Array(stringLength / 2);
  21. for (var i = 0; i < stringLength; i += 2) {
  22. result[i / 2] = parseInt(stringSlice(string, i, i + 2), 16);
  23. }
  24. return result;
  25. }
  26. });