Summary of progress

[Marcin 'Qrczak' Kowalczyk]

Mon, 12 Mar 2001 14:29:59 +0100 (MET), Johannes Waldmann <joe@isun.informatik.uni-leipzig.de> pisze:

> Do we need two types of `imports':
> `import Foo.Bar.M' imports a module, while
> `import Foo.Bar.*' does not actually import a module,
> but rather adds an element to the search path.

I would prefer to import module names like other names, i.e.

    import Foo.Bar -- It can make some module names visible.
    import M -- Imports Foo.Bar.M, assuming it exists. If more than
             -- one module called M is visible, it's an ambiguity
             -- error as usual.
    
    import Foo.Bar as F
    import F.M -- Same as above.

The only special thing about module names is that their prefixes are
automatically imported qualified, i.e to refer to
    Foo.Bar.M.f
you don't have to import each of Foo, Bar and M separately, but just
import fully M using its qualified name. This works for other names
in ghci.

Such Foo.Bar module is not defined explicitly, but results from
having a subdirectory in import directories. Contents of all Foo.Bar
directories from all import directory roots are merged to form such
pseudo-module which contains nothing but modules.

In a future version of Haskell, when module export list will specify
the interface and not only names, it will be possible to export
modules from other explicit modules. There will be no distinction
between modules which contain only modules and modules which contain
everything else.

-- 
 __("<  Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^                      SYGNATURA ZASTĘPCZA
QRCZAK