Re: [Scheme-reports] Import declarations in programs

[John Cowan <cowan@x>]

Marc Nieper-Wißkirchen scripsit:

> Both options are semantically fundamentally different so I
> don't think it is a good idea to leave this edge case open by the
> specification. What's worse I don't see any of the two options well
> justified.

In general, imposing a restriction is done only if it's justifiable,
and only if we think of it at the right time.  This ambiguity is easy to
work around: only use one import statement, or simply don't ever export
the name 'import' (I can assure you that no Scheme standard library will
do so!)

Although in principle any identifier can be rebound, there are known
problems with doing so in certain cases:  rebinding `quote`, for example,
will also rebind the ' syntax.  Adding `import` to the list of things
it's a Bad Idea to rebind is really not a big deal.

Finally, an implementer who feels strongly about this restriction can
enforce it in his implementation and list it as a derogation from the
standard.

-- 
John Cowan   cowan@x
    "Mr. Lane, if you ever wish anything that I can do, all you will have
        to do will be to send me a telegram asking and it will be done."
    "Mr. Hearst, if you ever get a telegram from me asking you to do
        anything, you can put the telegram down as a forgery."

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