<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Hello,</div><div><br></div><div>I知 having trouble getting the handin server to accept a BSL file that uses the image library and also includes template definitions. I can make it work separately. That is, I can accept BSL image program files as long as they don稚 have any templates and I can accept BSL programs with templates as long as they don稚 use images.</div><div><br></div><div>The problem is that when I go to require both <font face="Courier">2htdp/image</font> and <font face="Courier">lang/htdp-beginner</font> in the checker, there is a conflict with the <font face="Courier">image?</font> procedure being defined in both modules. Trying to use <span style="font-family: Menlo;">(except-in 2htdp/image image?)</span> inside the <font face="Courier">requires</font> list doesn稚 work.</div><div><br></div><div>What do I need to do to write a checker that will accept the student file shown below?</div><div><br></div><div>My broken checker is included below. (The student file will also have <font face="Courier">check-expect</font>s, which explains the presence of <font face="Courier">test-engine/racket-tests</font>.)</div><div><br></div><div>Suzanne</div><div><br></div><div>末末末-末末末-末末末-末末末-末末末-</div><div><br></div><div><div style="margin: 0px; font-family: Menlo;">;; broken checker!</div><div style="margin: 0px; font-family: Menlo;">#lang s-exp handin-server/checker</div><div style="margin: 0px; font-family: Menlo;">(require handin-server/grading-utils)</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">(pre: (check-deadline))</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">(check: <span style="color: rgb(239, 118, 238);">:language</span> 'racket</div><div style="margin: 0px; font-family: Menlo;"><span style="color: rgb(0, 0, 0);"> </span><span style="color: rgb(239, 118, 238);">:requires</span><span style="color: rgb(0, 0, 0);"> '(</span>2htdp/image<span style="color: rgb(255, 187, 28);"> ;;; (except-in 2htdp/image image?) </span></div><div style="margin: 0px; font-family: Menlo;"> test-engine/racket-tests</div><div style="margin: 0px; font-family: Menlo;"><span style="color: rgb(0, 0, 0);"> </span>lang/htdp-beginner)</div><div style="margin: 0px; font-family: Menlo; color: rgb(239, 118, 238);"><span style="color: #000000"> </span>:create-text?<span style="color: #000000"> #t</span></div><div style="margin: 0px; font-family: Menlo; color: rgb(239, 118, 238);"><span style="color: #000000"> </span>:textualize?<span style="color: #000000"> #f</span></div><div style="margin: 0px; font-family: Menlo;">)</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">(post: #f)</div></div><div><br></div><div><br></div><div><div style="margin: 0px; font-family: Menlo;">;; Student file to be submitted</div><div style="margin: 0px; font-family: Menlo;">(require 2htdp/image)</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">;; template:</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">(<span style="color: rgb(52, 187, 199);">define</span> (<span style="color: rgb(94, 52, 255);">process-strings</span> strings)</div><div style="margin: 0px; font-family: Menlo; color: rgb(52, 187, 199);"><span style="color: #000000"> (</span>cond</div><div style="margin: 0px; font-family: Menlo;"> [(empty? strings) ...]</div><div style="margin: 0px; font-family: Menlo;"> [else (... (first strings) ...</div><div style="margin: 0px; font-family: Menlo;"><span class="Apple-tab-span" style="white-space:pre"> </span> (process-strings (rest strings)))]))</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">;; function based on template:</div><div style="margin: 0px; font-family: Menlo; min-height: 16px;">(<span style="color: rgb(52, 187, 199);">define</span> (<span style="color: rgb(94, 52, 255);">make-color-chart</span> colors)</div><div style="margin: 0px; font-family: Menlo; color: rgb(52, 187, 199);"><span style="color: #000000"> (</span>cond</div><div style="margin: 0px; font-family: Menlo;"> [(empty? colors) empty-image]</div><div style="margin: 0px; font-family: Menlo;"> [else (beside</div><div style="margin: 0px; font-family: Menlo;"> (rectangle 30 100 <span style="color: #c59c9c">"solid"</span> (first colors))</div><div style="margin: 0px; font-family: Menlo;"> (make-color-chart (rest colors)))]))</div></div><div style="margin: 0px; font-family: Menlo;">(check-expect (image-width (make-color-chart empty)) 0)</div><div><br></div></body></html>