[racket] struct #:methods question

From: Carl Eastlund (cce at ccs.neu.edu)
Date: Wed Aug 28 12:14:28 EDT 2013

As far as I know, it has never been necessary to explicitly define absent
methods.  The paragraph is just describing what absent methods are
implicitly bound to by the #:methods form.  It used to be that methods were
bound as the value #f in the body of the #:methods definitions themselves,
so the documentation was clarifying what you'd get if you referred to
them.  Now, any undefined method is bound as syntax that will raise a
compile-time error if you refer to it without binding it, so the #f part is
completely invisible to the user.

Carl Eastlund

On Wed, Aug 28, 2013 at 10:15 AM, Asumu Takikawa <asumu at ccs.neu.edu> wrote:

> On 2013-08-28 11:14:50 +0200, Tobias Hammer wrote:
> > Can anyone explain the part with the #f to me? Does it mean that i
> > have to (define some-gen-fun #f) to indicate it's not implemented?
> > But that seems to have no real impact as i get the exactly same
> > error with just leaving it out?
> I think this is a mistake in the documentation. You are allowed to leave
> out any method definitions (without a #f definition). We probably forgot
> to delete that sentence after changing the syntax of method definitions
> at some point.
> Cheers,
> Asumu
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