<div dir="ltr"><div>Greg Hendershott's pages may be of interest to you: <a href="http://www.greghendershott.com/fear-of-macros/">http://www.greghendershott.com/fear-of-macros/</a> And I think you can find some worthwhile notes on the PLT blog too. </div>Laurent </div><div class="gmail_extra"> <div class="gmail_quote">On Thu, Jan 17, 2013 at 11:08 AM, Tim Brown <<a href="mailto:tim.brown@cityc.co.uk" target="_blank">tim.brown@cityc.co.uk</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Danny, Jens Axel, Ian, Ray, Thanks for your input... I'm absorbing it all. I need some really basic help getting my head around all of this. Where can I download a copy of "How to Design Macros"? :-) Tim<div class="im HOEnZb"> On 16/01/13 17:22, Jens Axel Søgaard wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi Tim, Danny explains the problem well. To accumulate a result, one must stay in the same same dynamic extent. One way to solve the problem is to use local-expand. In some cases one can write expanders for the forms, that needs analysing and call them directlye (rather than write a macro for the subform and then let the expander call a macro transformer). Below is a short example, which incidently shows an alternative solution the local-expand problem, I had the other day (see <a href="http://www.mail-archive.com/users@racket-lang.org/msg15937.html" target="_blank">http://www.mail-archive.com/users@racket-lang.org/msg15937.html</a> ). If you need local-expand, then see Matthews answer on how to use definition contexts with local-expand. /Jens Axel </blockquote> </div><div class="HOEnZb"><div class="h5"> -- Tim Brown <<a href="mailto:tim.brown@cityc.co.uk" target="_blank">tim.brown@cityc.co.uk</a>> | City Computing Limited | T: <a href="tel:%2B44%2020%208770%202110" value="+442087702110" target="_blank">+44 20 8770 2110</a> | City House, Sutton Park Road | F: <a href="tel:%2B44%2020%208770%202130" value="+442087702130" target="_blank">+44 20 8770 2130</a> | Sutton, Surrey, SM1 2AE, GB | -----------------------------------------------------------------------| BEAUTY: What's in your eye when you have a bee in your hand | -----------------------------------------------------------------------' City Computing Limited registered in London No. 1767817. Registered Office: City House, Sutton Park Road, Sutton, Surrey, SM1 2AE VAT number 372 8290 34. ____________________ Racket Users list: <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a> </div></div></blockquote></div> </div>