tag:blogger.com,1999:blog-27488238.post7425479667836352721..comments2007-04-21T04:13:15.546+02:00tawhttp://www.blogger.com/profile/16972845140253292628noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-27488238.post-18253844092088493732007-04-21T04:13:15.546+02:002007-04-21T04:13:15.546+02:00schemd does not lack a full macro system.<BR/>syntax-rules is not the only game in town; most modern schemes implement Dyvbig's syntax-case which allows you to do full macros with arbitrary symbol injection...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-27488238.post-49267957271142286902007-04-20T14:29:57.060+02:002007-04-20T14:29:57.060+02:00Fabien: I think I'll try to build optional Scheme-like macro system on top of default CL-like defmacro.tawhttp://www.blogger.com/profile/16972845140253292628noreply@blogger.comtag:blogger.com,1999:blog-27488238.post-2353046979656497162007-04-20T08:54:05.303+02:002007-04-20T08:54:05.303+02:00Notice that once you've got robust pattern matching, you're quite close to have hygienic macros: <BR/><BR/>- to avoid variable capture, just perform an alpha conversion of variables declared in a macro's quoted code<BR/><BR/>- to avoid change of open variables meaning, collect all of them in a hashtable at macro declaration time, and replace these variables by hashtable indexing in the maacro's body.<BR/><BR/>Both operations are rather easy to implement with pattern matching. I implemented the first half in metalua (http://metalua.luaforge.net), through pattern matching.<BR/><BR/>I didn't bother with the second half, because I want, by design, to get macros clearly separated from regular code. That's one of the ways in which metalua is not just Lisp-with-syntax :)Fabienhttp://www.blogger.com/profile/02739446213556869485noreply@blogger.com