<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Are you reading the desired field name from somewhere? </div><div><br></div><div><br></div><br><div><div>On Sep 6, 2011, at 2:29 PM, Todd Bittner wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Right, but what I want to do in this case is pass in 'x' and dynamically construct posn-x rather than pass in the accessor 'posn-x' itself.  In other words, I know I want to call a posn accessor, but I don't know which one yet.<br> <br>I want to dynamically build and call the method rather than just dynamically call the method.<br><br><div class="gmail_quote">On Tue, Sep 6, 2011 at 1:22 PM, Matthias Felleisen <span dir="ltr"><<a href="mailto:matthias@ccs.neu.edu">matthias@ccs.neu.edu</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><br> In Racket, accessors are functions and are thus perfectly legitimate arguments:<br> <br> (define (foo some-posn some-accessor)<br>  (some-accessor some-posn))<br> <br> > (foo my-posn posn-x)<br> 3<br> <div><div></div><div class="h5"><br> <br> <br> <br> <br></div></div> <br> </blockquote></div><br> </blockquote></div><br></body></html>