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Fri, 07 Mar 2014 14:49:03 +0200Fri, 07 Mar 2014 14:49:03 +0200On conservativity of concurrent Haskell
http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/34312
The calculus CHF models Concurrent Haskell extended by concurrent, implicit futures. It is a process calculus with concurrent threads, monadic concurrent evaluation, and includes a pure functional lambda-calculus which comprises data constructors, case-expressions, letrec-expressions, and Haskell’s seq. Futures can be implemented in Concurrent Haskell using the primitive unsafeInterleaveIO, which is available in most implementations of Haskell. Our main result is conservativity of CHF, that is, all equivalences of pure functional expressions are also valid in CHF. This implies that compiler optimizations and transformations from pure Haskell remain valid in Concurrent Haskell even if it is extended by futures. We also show that this is no longer valid if Concurrent Haskell is extended by the arbitrary use of unsafeInterleaveIO.David Sabel; Manfred Schmidt-Schaußworkingpaperhttp://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/34312Thu, 03 Jul 2014 14:49:03 +0200On conservativity of concurrent Haskell
http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/24252
The calculus CHF models Concurrent Haskell extended by concurrent, implicit futures. It is a process calculus with concurrent threads, monadic concurrent evaluation, and includes a pure functional lambda-calculus which comprises data constructors, case-expressions, letrec-expressions, and Haskell’s seq. Futures can be implemented in Concurrent Haskell using the primitive unsafeInterleaveIO, which is available in most implementations of Haskell. Our main result is conservativity of CHF, that is, all equivalences of pure functional expressions are also valid in CHF. This implies that compiler optimizations and transformations from pure Haskell remain valid in Concurrent Haskell even if it is extended by futures. We also show that this is no longer valid if Concurrent Haskell is extended by the arbitrary use of unsafeInterleaveIO.David Sabel; Manfred Schmidt-Schaußworkingpaperhttp://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/24252Tue, 07 Feb 2012 16:16:23 +0100An abstract machine for concurrent Haskell with futures
http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/24253
We show how Sestoft’s abstract machine for lazy evaluation of purely functional programs can be extended to evaluate expressions of the calculus CHF – a process calculus that models Concurrent Haskell extended by imperative and implicit futures. The abstract machine is modularly constructed by first adding monadic IO-actions to the machine and then in a second step we add concurrency. Our main result is that the abstract machine coincides with the original operational semantics of CHF, w.r.t. may- and should-convergence.David Sabelworkingpaperhttp://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/24253Tue, 07 Feb 2012 16:14:01 +0100