Library Extension

The LIBRARY! datatype in Rebol represented the idea of dynamically loadable code. It was used by the FFI to speak to an arbitrary DLL through C types, but also used by the extension mechanism itself to deal with specially constructed Rebol Extension DLLs--which can provide additional natives or ports to the system.

There's a bit of an unusual aspect to having the Library code in an extension, since it cannot itself be loaded dynamically.

The code was at one point tested in the continuous integration, with the UUID extension by building with "UUID " ( means dynamic) and this code:

- name: Test UUID Extension Built As DLL
  shell: r3built --fragment {0}  # See README: Ren-C Code As Step
  run: |
    print {== Hello From R3 DLL Test! ==}
    mod-uuid: load-extension join what-dir %build/libr3-uuid.so
    print {== UUID Extension Loaded ==}
    uuid: mod-uuid.generate
    assert [16 = length of uuid]
    print ["Succeeded:" uuid]

However it was removed because the feature isn't a high enough priority to be in the forefront and make it something that can be worked on independently, and not burden the rest of the system. (e.g. the JavaScript build cannot make use of the DLL handling).