[plt-scheme] required else for if ?

From: Doug Evans (dje at sebabeach.org)
Date: Sun Sep 6 18:35:14 EDT 2009

Noel Welsh wrote:
> On Sun, Sep 6, 2009 at 8:07 PM, Doug Evans<dje at sebabeach.org> wrote:
>> How come the default behaviour of `if' in mzscheme is to
>> require the else clause,
>> and not have an optional else clause?
> This is one of the changes made in the v3 -> v4 transition. It is
> designed to prevent a class of bugs. The mzscheme language provides
> backwards compatibility.

Thanks.  Can you elaborate on the "class of bugs"?

I realize mzscheme, rnrs, provide "backward" compatibility, but that 
route drags in a lot of other stuff that I don't necessarily want.

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