<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>Thanks, Vincent.</span></div><div><span><br></span></div><div><span>I didn't know traces had to be in the program itself.</span></div><div><span><br></span></div><div><span>Michael</span></div><div><br></div><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "><font size="2" face="Arial"><hr size="1"><b><span style="font-weight:bold;">From:</span></b> Vincent St-Amour <stamourv@ccs.neu.edu><br><b><span style="font-weight: bold;">To:</span></b> michael rice <nowgate@yahoo.com><br><b><span style="font-weight: bold;">Cc:</span></b> Vincent St-Amour <stamourv@ccs.neu.edu>; Racket Users <users@racket-lang.org><br><b><span style="font-weight: bold;">Sent:</span></b> Monday, October 10, 2011 1:49 PM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: [racket] Trace rejects set!<br></font><br> At Mon, 10 Oct 2011 10:31:39 -0700 (PDT),<br>michael rice wrote:<br>> <br>> Welcome to DrRacket, version 5.1.3 [3m].<br>> Language: racket; memory limit: 128 MB.<br>> > (trace next-leaf-generator)<br>> set!: cannot modify a constant: next-leaf-generator<br><br>Try adding `(trace next-leaf-generator)' to the program itself, that<br>should work.<br><br>The interactions window is not part of the program, which is in its<br>own module. Since you can't mutate variables except in the module<br>where they're defined, you can't add tracing from the interactions<br>window.<br><br>Vincent<br><br><br></div></div></div></body></html>