Re: Trouble with returning parameters passed in to C primitives.

[Richard Shann]

Thank you! I am much clearer on the meaning of quote now.
Richard Shann
> On Dec 7, 2012 5:51 AM, "Richard Shann" <address@hidden> wrote:
> > If I pass 'a in as a parameter I get something back which prints on
> the
> > console as (quote a) but which is not eq? to 'a
> 
> You seem to be double quoting the value.  No need for ' the second
> time.
> 
> > I can pass in a string and get an equal? string back. But what I
> really
> > want to do is pass in a procedure and execute it if I get it back,
> thus
> >
> > (set! choice (d-PopupMenu (list '("Offset Position" . do-offset))))
> 
> Here you pass the symbol "do-offset" rather than the value.  read up
> on quote and quasiquote syntax.  Use unquote to insert the /value/ of
> do-offset:
> 
> (set! choice (d-PopupMenu (list `("Offset Position" . ,do-offset))))
> 
> or:
> 
> (set! choice (d-PopupMenu (list (cons "Offset Position" do-offset))))
> 
> > (#f Wrong type to apply: ~S (do-offset) #f)
> >
> 
> You are trying to apply a list contain a symbol, when it should just
> be a procedure: no list or symbol.
>