On Wed, Nov 14, 2012 at 6:09 PM, Helmut Eller <[email protected]>wrote:

> On Wed, Nov 14 2012, Alex Shinn wrote:
>
> > On Wed, Nov 14, 2012 at 5:46 PM, Helmut Eller <[email protected]>
> wrote:
> >
> >     On Wed, Nov 14 2012, Alex Shinn wrote:
> >
> >     >     In Section 5.2 says that a REPL should permit to redefine
> existing
> >     >     definitions.  What should happen if a record definition is
> >     redefined?
> >     >     Should existing record instances be considered instances of
> the new
> >     >     type?
> >     >
> >     > Again, implementations differ here so there's not much
> >     > we can say.  Smalltalk-style class redefinition is a nice
> >     > feature, but fragile and not currently widely implemented.
> >
> >     You can say what "should" happen.
> >
> > We could say that iff everyone agreed on what should happen.
>
> Then why can you say that a REPL "should" support redefinition?
> (Without defining what redefinition means.)
>

This refers to redefining variables and syntax in general.

For the specific case of redefining record types we could
add a note that existing instances may or may not be
mapped to the new type according to some unspecified
semantics, but I'm not sure if such a note adds anything.

-- 
Alex
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