Fixing contracts and a little less allocation

original commit: ba31d8c4299841efb9272340dad4a9c6cd26b035

collects/scribble/sigplan.rkt

@@ -27,13 +27,13 @@
  [category
   (->* (pre-content? pre-content? pre-content?)
        ((or/c false/c pre-content?))
-       block?)]
+       content?)]
  [terms
   (->* () () #:rest (listof pre-content?)
-       block?)]
+       content?)]
  [keywords
   (->* () () #:rest (listof pre-content?)
-       block?)])
+       content?)])
 
 (provide preprint 10pt
          include-abstract)
@@ -122,11 +122,10 @@
 (define (category sec title sub [more #f])
   (make-multiarg-element
    (make-style (format "SCategory~a" (if more "Plus" "")) sigplan-extras)
-   (append
-    (list
-     (make-element #f (decode-content (list sec)))
-     (make-element #f (decode-content (list title)))
-     (make-element #f (decode-content (list sub))))
+   (list*
+    (make-element #f (decode-content (list sec)))
+    (make-element #f (decode-content (list title)))
+    (make-element #f (decode-content (list sub)))
     (if more
         (list (make-element #f (decode-content (list more))))
         null))))

collects/scribblings/scribble/sigplan.scrbl

@@ -65,9 +65,9 @@ Declares information that is collected into the copyright region of the paper.}
 @defproc[(category [CR-number pre-content?] 
                    [subcategory pre-content?]
                    [third-level pre-content?]
-                   [fourth-level (or/c #f pre-content?) #f]) block?]
-@defproc[(terms [content pre-content?] ...) block?]
-@defproc[(keywords [content pre-content?] ...) block?]
+                   [fourth-level (or/c #f pre-content?) #f]) content?]
+@defproc[(terms [content pre-content?] ...) content?]
+@defproc[(keywords [content pre-content?] ...) content?]
 )]{
 
 Typesets category, term, and keyword information for the paper, which