59 lines
1.6 KiB
ReStructuredText
59 lines
1.6 KiB
ReStructuredText
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Dynamic Loading of Packages with Findlib
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========================================
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.. TODO(diataxis) this is an howto
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The preferred way for new development is to use :ref:`plugins`.
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Dune supports the ``findlib.dynload`` package from `Findlib
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<http://projects.camlcity.org/projects/findlib.html>`_ that enables
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dynamically-loading packages and their dependencies (using the OCaml Dynlink module).
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Adding the ability for an application to have plugins just requires adding
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``findlib.dynload`` to the set of library dependencies:
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.. code:: dune
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(library
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(name mytool)
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(public_name mytool)
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(modules ...)
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)
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(executable
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(name main)
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(public_name mytool)
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(libraries mytool findlib.dynload)
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(modules ...)
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)
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Use ``Fl_dynload.load_packages l`` in your application to load
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the list ``l`` of packages. The packages are loaded
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only once, so trying to load a package statically linked does nothing.
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A plugin creator just needs to link to your library:
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.. code:: dune
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(library
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(name mytool_plugin_a)
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(public_name mytool-plugin-a)
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(libraries mytool)
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)
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For clarity, choose a naming convention. For example, all the plugins of
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``mytool`` should start with ``mytool-plugin-``. You can automatically
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load all the plugins installed for your tool by listing the existing packages:
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.. code:: ocaml
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let () = Findlib.init ()
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let () =
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let pkgs = Fl_package_base.list_packages () in
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let pkgs =
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List.filter
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(fun pkg -> 14 <= String.length pkg && String.sub pkg 0 14 = "mytool-plugin-")
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pkgs
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in
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Fl_dynload.load_packages pkgs
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