[Haskell-cafe] using a win32 dll (Happy too soon)

[Brandon Allbery]

On Thu, May 30, 2013 at 11:46 AM, Kees Bleijenberg <
k.bleijenberg at lijbrandt.nl> wrote:

> Brandon, thanks again for your explanation
> Are you sure about the non existing search order for dynamic loaded dll’s?
> I.e.
> http://msdn.microsoft.com/en-us/library/windows/desktop/ms682586(v=vs.85).aspx#standard_search_order_for_desktop_applicationssays there is a search order, starting with the current directory (I think).
>

There is a search order. What I said is that there are no standard
locations to install things. That is, every library package stows stuff in
its own directory structure and no compiler can possibly know all the
places it needs to look to find every library off in its own directory.


> I don’t understand why the linker needs to see the dll anyway.


Because it's better to catch "that symbol doesn't exist" at build time
instead of throwing an ugly error at runtime, among other things.


> possible in Delphi. Is Haskell dynamic loading more limited?
>

There are ways to do that kind of dynamic linking; this is not one of them.
C and C++ don't automatically dynload the way you're thinking either,
because you should test for the DLL you're distributing (you are
distributing it, right, not forcing the end user on a wild goose chase to
find their own copy of the DLL, hoping it's the right/compatible version,
and figure out where to put it so your program will run?) being the right
one *when you build the program*, not defer that test until it is run.

If you think about it, this is very similar to doing your type checking at
compile time instead of runtime. If you want lazy type checking, why are
you using Haskell? If you want lazy library checking, why are you using a
compiler?

-- 
brandon s allbery kf8nh                               sine nomine associates
allbery.b at gmail.com                                  ballbery at sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net
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