What are some Haskell libraries for error handling?

What are some Haskell libraries for error handling?

There are several libraries in Haskell that are great for error handling. Some popular ones include:

1. Either - A standard way to represent computations that can fail.
2. Maybe - Useful for computations that might not return a value.
3. exceptions - Provides a way to handle exceptions in a more controlled manner.
4. transformers - Allows you to combine different monads, including error handling.
5. MonadError - A type class for monads that can throw errors. Would you like to know more about any specific library?

Can you explain how the Either library works?

Sure! The Either type in Haskell is used to represent a value that can be one of two types. It has two constructors: Left and Right. Typically, Left is used to represent an error, while Right represents a successful result. For example:

result :: Either String Int
result = Right 42  -- This indicates success with the value 42

errorResult :: Either String Int
errorResult = Left "An error occurred"  -- This indicates failure with an error message

You can use pattern matching to handle both cases. Would you like to see an example of how to use it in a function?

Yes, please show me an example function using Either.

Here's a simple example of a function that divides two numbers and uses Either to handle potential division by zero:

safeDivide :: Int -> Int -> Either String Int
safeDivide _ 0 = Left "Cannot divide by zero"
safeDivide x y = Right (x `div` y)

In this function, if the second argument is zero, it returns a Left with an error message. Otherwise, it returns a Right with the result of the division. Would you like to explore more examples or other libraries?