Haskell provides a principled approach to error handling through its type system and the use of monads. Rather than relying on exceptions like in some other programming languages, Haskell encourages the use of pure functions and explicit error handling. Here are some key mechanisms Haskell uses for error handling:

1. Maybe and Either Types :
   * Haskell uses the `Maybe` and `Either` types to handle the possibility of errors or exceptional situations.
   * The `Maybe` type represents an optional value that can either be `Just a`, where `a` is the value, or `Nothing`, representing the absence of a value.
   * The `Either` type represents a value that can be either a successful result (`Right a`) or an error value (`Left err`). This allows for explicit handling of different error conditions.

2. Result Monads :
   * Haskell leverages monads, such as `Maybe` and `Either`, to propagate and handle errors in a controlled and composable manner.
   * For example, the `Maybe` monad is used to handle computations that may fail. By chaining computations with the `Maybe` monad, error propagation and short-circuiting can be easily managed. 3. Custom Data Types :
   * Haskell encourages the use of custom data types to represent specific error cases or exceptional situations.
   * By defining custom ADTs (Algebraic Data Types), you can create data structures that explicitly represent different error conditions. This allows for precise error modeling and pattern matching on specific error cases.

4. Explicit Error Reporting :
   * Haskell encourages explicit error reporting by using functions to signal and handle errors explicitly.
   * Functions often return `Maybe` or `Either` types to indicate the success or failure of a computation, providing clear information about potential errors.

5. Exception Handling :
   * While Haskell prefers explicit error handling, it does provide a mechanism for dealing with exceptional situations through the use of the `IO` monad and exceptions.
   * The `Control.Exception` module provides functions and types for catching and handling exceptions within the `IO` monad, allowing for more traditional exception handling when necessary.