PreferGlobalFunction

Severity: Low | Category: Optimization

Detects contract methods that do not access internal state and suggests replacing them with global functions.

Why is it bad?

• Gas inefficiency: Contract method calls (self.func()) cost more gas than global function calls (func()) due to unnecessary self context resolution.
• Cleaner code: Global functions better represent stateless logic, making intent clearer.

See: https://docs.tact-lang.org/book/gas-best-practices/#avoid-internal-contract-functions

Example

contract Math {
  // Bad: `add()` doesn't use `self`
  fun add(a: Int, b: Int): Int {
    return a + b;
  }
  // other methods
}

Use instead:

// Good: Replace with a global function
fun add(a: Int, b: Int): Int {
  return a + b;
}
contract Math {
  // other methods
}