<div class="gmail_quote">On Tue, Dec 8, 2009 at 17:32, Laurent <<a href="mailto:laurent.orseau@gmail.com">laurent.orseau@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> And, BTW, despite the use of `define-syntax-rule', when omitting the `source' argument in the `init-field-clone' definition, the form still works but becomes non-hygienic! Now I have to completely rewire my brain again... </blockquote><div> More exactly: `source' can be omitted from the arguments: <blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex; font-family: courier new,monospace;" class="gmail_quote"> (define-syntax-rule (init-field-clone [var val] ...) (begin (init [source #f]) (init-field [var (if source (get-field var source) val)] ...))) </blockquote> it seems that `source' is inaccessible, but then it cannot be used as a field anymore: </div></div> <blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex; font-family: courier new,monospace;" class="gmail_quote">> (define c1% (class object% (init-field-clone [source "z"]) (super-new) )) error: class: duplicate declared external init name in: source </blockquote> how can this be if the macro is hygienic? Well, of course, if it were completely internalized, I could not instantiate c1% with `new'... Does that means that it is `init' or `init-field' that are non-hygienic?