Control.Exception

This module provides support for raising and catching both built-in and user-defined exceptions. In addition to exceptions thrown by IO operations, exceptions may be thrown by pure code (imprecise exceptions) or by external events (asynchronous exceptions), but may only be caught in the IO monad. For more details, see: A semantics for imprecise exceptions, by Simon Peyton Jones, Alastair Reid, Ton

[miruzouq]

はすけのはこんな感じなのかあ…“An IOException records a more specific error type, a descriptive string and maybe the handle that was used when the error was flagged.”