<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> Razvan Rotaru wrote at 12/30/2010 10:34 AM: <blockquote cite="mid:610918.15417.qm@web111406.mail.gq1.yahoo.com" type="cite"> <style type="text/css"></style> <div style="" roman="" new="" york="" times="" ,="" serif;font-size:12pt=""> <div>I was just wondering whether there is anything like setf in scheme.<br> </div> </div> </blockquote> <br> If you mean like "set!" to accept place lvalues, SRFI-17 is one example:<br> <br> <a class="moz-txt-link-freetext" href="http://srfi.schemers.org/srfi-17/srfi-17.html">http://srfi.schemers.org/srfi-17/srfi-17.html</a><br> <br> Implementing such a thing for a small, fixed set of places (like "car") using only macros is easy.<br> <br> If, however, you want it extensible to new setters, I think you'd end up defining matching setting procedures and hanging them off the getter procedures as (depending on what your Racket or Scheme version has) symbol properties, record-type-as-procedure, or some similar feature.<br> <br> Setters like this have sometimes seemed to me to provide a nice linguistic symmetry, but at the same time, they are growing the language quite a bit despite the appeal of simplicity.  In practice, I have never wanted to have setters.  IMHO.<br> <br> <div class="moz-signature">-- <br> <a class="moz-txt-link-freetext" href="http://www.neilvandyke.org/">http://www.neilvandyke.org/</a> </div> </body> </html>