I think that we should try a different approach, forget about
the importing
mechanism, and make a single statement defining the intended semantics.
Section 1.2 (The Haskell Kernel) is the place. I propose adding the
following.
The translations given, and the identities given for the semantics of
case expressions, are not macros. A simple replacement of the
right-hand-side for the left-hand-side with substitution of parameters
does
not give the intended semantics. The reason for this is that the
translations make use of certain names defined in the standard prelude
(see
section 5.4), and macro substitution could result in the capture of
these
names by locally defined entities, or the use of a name in a context in
which it is not defined at all because the part of the prelude in which
it
is defined has not been imported. The general rule is: the use of a name
defined in the standard prelude in a translation intended to show the
semantics of a construct always implies the definition in the standard
prelude.
Then, people can locally rebind as much as they want, but the constructs
defined by translation will be unaffected.
This sounds reasonable to me. -Paul
