<!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 11:37 AM: <blockquote cite="mid:758465.69376.qm@web111402.mail.gq1.yahoo.com" type="cite"> <style type="text/css"></style> <div style="" roman="" new="" york="" times="" ,="" serif;font-size:12pt=""> <div>In what sense would they grow the language? By adding an abstractisation layer, or by building it in the language. </div> <div>It seems to me (correct me if I'm wrong) that implementing such thing in scheme is complex only because scheme does not have lvalues (as things that an expression can be evaluated to, that is).<br> </div> </div> </blockquote> <br> At (at least) a syntactic level, it's making what were simple getter procedures somehow be usable as both getters and setters, and I think that complicates the language.  Or changes it substantially.<br> <br> However, I suspect that implementing this linguistic complication in Racket is easy.  I would first try "prop:procedure" in the documentation, and a simple notion of lvalues that is used only by "set!".<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>