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  • can haskell do this?

    From Benjamin L. Russell@21:1/5 to [email protected] on Sun May 12 16:43:55 2019
    On Fri, 10 May 2019 08:06:41 -0700 (PDT), Rabican
    <[email protected]> wrote:

    https://www.scylladb.com/2019/05/06/introducing-scylla-enterprise-2019-1/

    I always like hearing the subject heading "Can Haskell Do This",
    because (unless we're talking an undecidable problem), since Haskell
    is Turing-complete, the answer is trivially YES.

    On the other hand, since Haskell does not provide a ScyllaDB
    interface, the answer is, equally trivially, NO. On the third hand,
    Haskell allows you to WRITE ScyllaDB, so the answer again becomes YES.

    Since you didn't really explain what you meant by `Haskell', or what
    you meant by `do this', your question has no useful answer. Perhaps if
    you refined your question, you might get something more worthwhile.

    In the case of ScyllaDB, a cursory examination of the website
    indicates that it's written in C++. Therefore, any Haskell system with
    a C/C++ FFI should be able to access it. Currently, one way of
    possibly accomplishing this task might be to use the procedure
    described at the Web page "CPlusPlus from Haskell" (see https://wiki.haskell.org/CPlusPlus_from_Haskell); _viz._:

    According to the Foreign Function Interface section of the Haskell
    2010 report, you import a C++ function by simply specifying the calling convention cplusplus. Unfortunately, no Haskell compiler actually supports this calling convention, so we have to use the C calling convention instead.

    The standard method for dealing with this is to write C++ code that uses extern "C" to export the methods unmangled. Of course, you still have to uniquify the method names, but *you* get to pick the names instead of
    letting the compiler do whatever wacky method it wants.

    The method presented on this page does not use that method � it just
    calls the mangled names directly. So far this seems to work OK...
    --
    Benjamin L. Russell / DekuDekuplex at Yahoo dot com http://dekudekuplex.wordpress.com/
    Computer Science Document Translator/Editor
    "Furuike ya, kawazu tobikomu mizu no oto." -- Matsuo Basho^

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  • From Paul Rubin@21:1/5 to Benjamin L. Russell on Sun May 12 01:10:06 2019
    Benjamin L. Russell <[email protected]> writes:
    On the other hand, since Haskell does not provide a ScyllaDB
    interface, the answer is, equally trivially, NO. On the third hand,
    Haskell allows you to WRITE ScyllaDB, so the answer again becomes YES.

    Or in more complete form, "The answer is: Yes! Haskell can do that."

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