or

Function Signature

(or b1 b2 ...)

• Input: bool, ...
• Output: bool

Why it matters

The or function is crucial for:

1. Implementing logical disjunction in conditional statements.
2. Simplifying the process of evaluating multiple boolean expressions.
3. Enhancing code readability and maintainability by abstracting logical disjunction.

When to use it

Use or when you need to:

• Evaluate multiple boolean expressions and return true if any are true.
• Implement logical disjunction in conditional statements.
• Simplify and abstract the process of evaluating multiple boolean values.

Best Practices

• Ensure all inputs are boolean expressions.
• Use meaningful variable names for better readability.
• Combine with other logical functions for comprehensive boolean logic.
• Be aware of the performance implications of complex logical operations.

Practical Example: Evaluating Multiple Conditions

Let's implement a function that checks if a number is either zero or negative:

(define-read-only (is-zero-or-negative (n int))
  (or (is-eq n 0) (< n 0))
)

;; Usage
(is-zero-or-negative 5) ;; Returns false
(is-zero-or-negative 0) ;; Returns true
(is-zero-or-negative -3) ;; Returns true

This example demonstrates:

1. Using or to evaluate multiple boolean expressions.
2. Implementing a read-only function to check if a number is either zero or negative.
3. Handling both true and false cases.

Common Pitfalls

1. Using or with non-boolean expressions, causing type errors.
2. Assuming the result will always be true or false, leading to incorrect logic.
3. Not handling all possible conditions, resulting in incomplete boolean logic.
4. Overlooking the need for proper error handling and validation.

Related Functions

• and: Logical conjunction of multiple boolean expressions.
• not: Logical negation of a boolean expression.
• is-eq: Checks if two values are equal.

Conclusion

The or function is a fundamental tool for implementing logical disjunction in Clarity smart contracts. It allows developers to evaluate multiple boolean expressions, enabling robust and comprehensive boolean logic. When used effectively, or enhances the reliability and maintainability of your smart contract code by providing a clear and concise way to manage logical disjunction.