Control.Monad.Trans.Region.Unsafe

regions-0.4: Provides the region monad for safely opening and working with scarce resources.

Source code

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Maintainer

Bas van Dijk <v.dijk.bas@gmail.com>

Description

WARNING: This module should not be used by end-users directly because it allows access to the internalHandle of a resource which enables them to close the resource manually, which will defeat the safety-guarantees that this package provides!

Synopsis

internalHandle :: RegionalHandle resource r -> Handle resource

mapInternalHandle :: (Handle resource1 -> Handle resource2) -> RegionalHandle resource1 r -> RegionalHandle resource2 r

Documentation

internalHandle :: RegionalHandle resource r -> Handle resource

Source

Get the internal handle from the given regional handle.

Warning: This function should not be exported to or used by end-users because it allows them to close the handle manually, which will defeat the safety-guarantees that this package provides!

Tip: If you enable the ViewPatterns language extension you can use internalHandle as a view-pattern as in the following example from the usb-safe package:

      resetDevice :: (pr `ParentOf` cr, MonadIO cr)
                  -> RegionalHandle USB.Device pr -> cr ()
      resetDevice (internalHandle -> (DeviceHandle ...)) = ...

mapInternalHandle :: (Handle resource1 -> Handle resource2) -> RegionalHandle resource1 r -> RegionalHandle resource2 r

Source

Modify the internal handle from the given regional handle.

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