| Copyright | (c) The University of Glasgow 2001 |
|---|---|
| License | BSD-style (see the file libraries/base/LICENSE) |
| Maintainer | [email protected] |
| Stability | experimental |
| Portability | non-portable (requires universal quantification for runST) |
| Safe Haskell | Unsafe |
| Language | Haskell2010 |
This library provides support for strict state threads, as described in the PLDI '94 paper by John Launchbury and Simon Peyton Jones Lazy Functional State Threads.
Unsafe API.
unsafeInterleaveST :: ST s a -> ST s a Source
unsafeInterleaveST allows an ST computation to be deferred lazily. When passed a value of type ST a, the ST computation will only be performed when the value of the a is demanded.
unsafeDupableInterleaveST :: ST s a -> ST s a Source
unsafeDupableInterleaveST allows an ST computation to be deferred lazily. When passed a value of type ST a, the ST computation will only be performed when the value of the a is demanded.
The computation may be performed multiple times by different threads, possibly at the same time. To prevent this, use unsafeInterleaveST instead.
Since: base-4.11
unsafeIOToST :: IO a -> ST s a Source
Convert an IO action to an ST action. This relies on IO and ST having the same representation modulo the constraint on the state thread type parameter.
unsafeSTToIO :: ST s a -> IO a Source
Convert an ST action to an IO action. This relies on IO and ST having the same representation modulo the constraint on the state thread type parameter.
For an example demonstrating why this is unsafe, see https://mail.haskell.org/pipermail/haskell-cafe/2009-April/060719.html
© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/8.8.3/docs/html/libraries/base-4.13.0.0/Control-Monad-ST-Unsafe.html