ok

Function Signature

(ok value)

• Input: A
• Output: (response A B)

Why it matters

The ok function is crucial for:

1. Constructing a successful response type.
2. Indicating that a function executed successfully.
3. Ensuring data integrity by clearly distinguishing between success and error states.
4. Simplifying the process of handling function return values in smart contracts.

When to use it

Use ok when you need to:

• Construct a successful response type.
• Indicate that a function executed successfully.
• Clearly distinguish between success and error states.
• Handle function return values in your smart contract.

Best Practices

• Ensure the value passed to ok is the intended successful result.
• Use meaningful variable names for better readability.
• Combine with err for comprehensive response handling.
• Handle the possible error cases to ensure robust contract behavior.

Practical Example: Returning a Successful Response

Let's implement a function that returns a successful response with a value:

(define-read-only (get-successful-response (value int))
  (ok value)
)

;; Usage
(get-successful-response 5) ;; Returns (ok 5)

This example demonstrates:

1. Using ok to construct a successful response type.
2. Implementing a read-only function to return a successful response.
3. Handling the successful response case.

Common Pitfalls

1. Using ok with an incorrect or invalid value, causing unexpected behavior.
2. Assuming the response will always be successful, leading to unhandled error cases.
3. Not handling all possible conditions, resulting in incomplete response handling.
4. Overlooking the need for proper error handling and validation.

Related Functions

• err: Constructs an error response type.
• match: Handles different branches or cases for optional and response types.

Conclusion

The ok function is a fundamental tool for constructing successful response types in Clarity smart contracts. It allows developers to indicate successful function execution, ensure data integrity, and simplify response handling. When used effectively, ok enhances the reliability and maintainability of your smart contract code by providing a clear and concise way to handle successful responses.