| Safe Haskell | Safe |
|---|---|
| Language | Haskell98 |
Test.IOSpec.IORef
Description
A pure specification of mutable variables.
Synopsis
- data IORefS a
- data IORef a
- newIORef :: (Typeable a, IORefS :<: f) => a -> IOSpec f (IORef a)
- readIORef :: (Typeable a, IORefS :<: f) => IORef a -> IOSpec f a
- writeIORef :: (Typeable a, IORefS :<: f) => IORef a -> a -> IOSpec f ()
- modifyIORef :: (Typeable a, IORefS :<: f) => IORef a -> (a -> a) -> IOSpec f ()
The IORefS spec
An expression of type IOSpec IORefS a corresponds to an IO
computation that uses mutable references and returns a value of
type a.
Manipulation and creation of IORefs
A mutable variable storing a value of type a. Note that the
types stored by an IORef are assumed to be Typeable.
newIORef :: (Typeable a, IORefS :<: f) => a -> IOSpec f (IORef a) Source #
The newIORef function creates a new mutable variable.
readIORef :: (Typeable a, IORefS :<: f) => IORef a -> IOSpec f a Source #
The readIORef function reads the value stored in a mutable variable.
writeIORef :: (Typeable a, IORefS :<: f) => IORef a -> a -> IOSpec f () Source #
The writeIORef function overwrites the value stored in a
mutable variable.
modifyIORef :: (Typeable a, IORefS :<: f) => IORef a -> (a -> a) -> IOSpec f () Source #
The modifyIORef function applies a function to the value stored in
and IORef.