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  1. function lengthDecorator(fun) {
  2. 	function update(len) {
  3. 		var args = [];
  4. 		for (var i = 0; i < len; ++i) {
  5. 			args.push('a' + i);
  6. 		}
  7. 		var result = new Function('fun',
  8. 			'return function(' + args.join(',') + ') {' +
  9. 				'var args = Array.prototype.slice.call(arguments);' +
  10. 				'return fun.apply(this, args);' +
  11. 			'}'
  12. 		);
  13. 		result = result(fun);
  14. 		result.update = update;
  15. 		return result;
  16. 	}
  17. 	return update(fun.length);
  18. }
  19.  
  20. var foo = lengthDecorator(function(a,b) {
  21. 	return a+b;
  22. });
  23.  
  24. print('foo.length: ' + foo.length);
  25. print('foo(2, 3): ' + foo(2, 3));
  26.  
  27. print('');
  28. foo = foo.update(42);
  29. print('foo.length: ' + foo.length);
  30. print('foo(2, 3): ' + foo(2, 3));
Success #stdin #stdout 0.01s 4940KB
comments (?)
stdin 
Standard input is empty
stdout 
foo.length: 2
foo(2, 3): 5

foo.length: 42
foo(2, 3): 5
https://ideone.com/0th5v
language:
JavaScript (SMonkey 60.2.3)
created:
11 years ago
visibility:
public

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