Basics
Crystal Errors
Handling Crystal Errors
Crystal errors use rescue with typed exception handling.
Introduction to Error Handling in Crystal
In Crystal, error handling is primarily done using exception handling. Crystal uses a mechanism known as rescue to manage exceptions, allowing developers to handle errors gracefully. This guide will explore how to use rescue and typed exception handling to effectively manage errors in Crystal applications.
Using Rescue for Error Handling
The begin and rescue blocks are used in Crystal to handle exceptions. When a block of code within the begin block raises an exception, the rescue block is executed. This mechanism allows you to manage errors and define alternative flows of execution.
Here's the basic syntax:
Typed Exception Handling
Crystal supports typed exception handling, meaning you can specify the type of exception you want to catch. This feature allows for more granular control over different types of errors. For example, you might want to handle a DivisionByZeroError differently from a FileNotFoundError.
Here's how you can implement typed exception handling:
Raising Exceptions
In some cases, you might want to raise an exception deliberately to indicate an error condition. In Crystal, you can use the raise keyword for this purpose. This is often used in conjunction with custom error messages or when certain conditions in your program are not met.
Here's an example of raising an exception:
Best Practices for Error Handling
- Always handle exceptions to prevent your application from crashing unexpectedly.
- Use typed exceptions for more precise error management.
- Log error details for easier debugging and maintenance.
- Avoid using exceptions for regular control flow; reserve them for exceptional circumstances.
