<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=us-ascii" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 8.00.7600.16722"></HEAD> <BODY> <DIV dir=ltr align=left><SPAN class=752261114-07042011><FONT color=#0000ff size=2 face=Arial>Also very interesting is eli's <A href="http://blog.racket-lang.org/2008/02/dirty-looking-hygiene.html">http://blog.racket-lang.org/2008/02/dirty-looking-hygiene.html</A></FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=752261114-07042011><FONT color=#0000ff size=2 face=Arial>Teaches how to ittify with syntax-rules and <FONT size=3>syntax-parameterize.</FONT></FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=752261114-07042011><FONT color=#0000ff size=2 face=Arial>Jos</FONT></SPAN></DIV><BR> <BLOCKQUOTE style="BORDER-LEFT: #0000ff 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"> <DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left> <HR tabIndex=-1> <FONT size=2 face=Tahoma><B>From:</B> users-bounces@racket-lang.org [mailto:users-bounces@racket-lang.org] <B>On Behalf Of </B>Stephen De Gabrielle<BR><B>Sent:</B> 05 April 2011 11:10<BR><B>To:</B> users<BR><B>Subject:</B> Re: [racket] Newbie question: Teach Yourself Scheme in Fixnum Days- macros<BR></FONT><BR></DIV> <DIV></DIV> <DIV>In case any lurkers like me are interested.</DIV> <DIV><A href="http://blog.racket-lang.org/2011/04/writing-syntax-case-macros.html">http://blog.racket-lang.org/2011/04/writing-syntax-case-macros.html</A></DIV> <DIV> </DIV> <DIV>Stephen</DIV> <DIV><BR> </DIV> <DIV class=gmail_quote>On Tue, Apr 5, 2011 at 12:51 AM, Robby Findler <SPAN dir=ltr><<A href="mailto:robby@eecs.northwestern.edu">robby@eecs.northwestern.edu</A>></SPAN> wrote:<BR> <BLOCKQUOTE style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class=gmail_quote> <DIV class=im>On Mon, Apr 4, 2011 at 6:25 PM, Eli Barzilay <<A href="mailto:eli@barzilay.org">eli@barzilay.org</A>> wrote:<BR>> Four hours ago, Robby Findler wrote:<BR>>><BR>>> It looks like a great macro essay for a certain crowd (altho the<BR>>> essay seems to insult that selfsame crowd; perhaps you are assuming<BR>>> that that crowd is into S&M?).<BR>><BR>> Where's the insult?  (I didn't mean any insult -- the only thing I can<BR>> think of is the "nostalgia" reference, which is not an insult but the<BR>> often expressed sentiment for "a simple system, like `defmacro'".)<BR><BR></DIV>Well, the scare quotes are a way to put down things, generally speaking.<BR> <DIV class=im><BR>><BR>>> Some comments:<BR>>><BR>>>  - I probably would have used #` in the second while macro. Yes, I<BR>>> see you mention it later, but doing it at that point seems to fit<BR>>> with what the reader's been given at that point<BR>><BR>> Well, that's one point where the purpose of the document is different<BR>> from a generic guide: my main goal was to write a quick intro to<BR>> people who are familiar with `defmacro' -- so I wanted to make it very<BR>> clear that it's the same kind of thing, only with wrapped sexprs<BR>> instead of raw ones.  In this case, I think that the long route is<BR>> better -- it shows that the extra tools (like #`) make things easier<BR>> only after you're aware of what goes on (and the fact that there's no<BR>> complicated magic involved, which is the frequent complain against<BR>> `syntax-case').<BR><BR></DIV>Yes, and the second while macro is a fine place to say that, in my<BR>opinion. Indeed, it seems like the most natural point to go to next<BR>and then to continue later to say what is happening with the # on the<BR>front. This is just how your text is already building (in a good way<BR>imo).<BR> <DIV class=im><BR>><BR>>>  - it would be good if you did some kind of a computation at compile<BR>>> time, preferably to demonstrate an interesting computation one<BR>>> should want to do at compile time. Maybe a macro that embeds a<BR>>> formatted source location into its output?<BR>><BR>> Good idea, I'll add something.<BR>><BR>><BR>>>  - cpp macros are, I believe, based on lexemes, not strings (so you<BR>>> cannot have an unclosed string in a macro or something).<BR>><BR>> Yeah, I couldn't find a way to phrase it better than stick a random<BR>> "roughly" in.  Using "lexemes" is a good word to describe it, but it's<BR>> a little too opaque -- any ideas for something more light?<BR><BR></DIV>"lexical tokens, like strings, parens, ..."?<BR> <DIV class=im><BR>><BR>>> At least nowadays they are.<BR>><BR>> Yes -- I definitely have used `#define's with a double-quote opener.<BR><BR></DIV>I think you can still pass an arg to gcc to get the old behavior back.<BR><FONT color=#888888><BR>Robby<BR></FONT> <DIV> <DIV></DIV> <DIV class=h5><BR>_________________________________________________<BR> For list-related administrative tasks:<BR> <A href="http://lists.racket-lang.org/listinfo/users" target=_blank>http://lists.racket-lang.org/listinfo/users</A></DIV></DIV></BLOCKQUOTE></DIV><BR><BR clear=all><BR></BLOCKQUOTE></BODY></HTML>