Code Generation with Examples

Generate a {{language}} function based on the description. Follow the style and conventions shown in the examples.

Example 1:
Description: Check if a string is a palindrome
Function:
function isPalindrome(str: string): boolean {
  const cleaned = str.toLowerCase().replace(/[^a-z0-9]/g, '');
  return cleaned === cleaned.split('').reverse().join('');
}

Example 2:
Description: Calculate the factorial of a number
Function:
function factorial(n: number): number {
  if (n < 0) throw new Error('Negative numbers not supported');
  if (n <= 1) return 1;
  return n * factorial(n - 1);
}

Now generate:
Description: {{function_description}}
Function: