comments on unstable libraries

collects/unstable/bytes.rkt

@@ -21,6 +21,8 @@
 ;;   "read with bytes".  Regardless, I see little point in composing two
 ;;   functions where the two names are clear enough -- you might consider
 ;;   looking at the version in CL.
+;; Ryan: I agree. More useful would be a version that checked that the
+;; bytes contains only one S-expr and errors otherwise.
 
 (define (write/bytes v)
   (define by (open-output-bytes))

collects/unstable/contract.rkt

@@ -9,13 +9,6 @@
 (define port-number? (between/c 1 65535))
 (define tcp-listen-port? (between/c 0 65535))
 
-(define non-empty-string/c
-  (and/c string?
-         (lambda (s) (not (zero? (string-length s))))))
-;; Eli: If this gets in, there should also be versions for bytes, lists, and
-;;   vectors.
-;; Ryan: How about just making these predicates? Predicates are more broadly applicable,
-;;   and when used as a contract we get the descriptive name for free.
 (define (non-empty-string? x)
   (and (string? x) (not (zero? (string-length x)))))
 (define (non-empty-bytes? x)

collects/unstable/dict.rkt

@@ -9,10 +9,11 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (define (dict-empty? dict)
-  (= (dict-count dict) 0))
+  (not (dict-iterate-first dict)))
 ;; Eli: This encourages ignoring the actual representation, and the fact
 ;; that `dict-count' can in some cases be an O(N) operation.  (And to
 ;; make things worse, it's not even mentioned in the docs.)
+;; Ryan: Fixed complexity.
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -135,6 +136,10 @@
 ;; union of two alists, etc.  Alternatively, just write a function for
 ;; merging two hash tables (and call it `hash-union', of course).
 
+;; Ryan: I prefer the names dict-add-all and dict-add-all!---no connotations
+;; of symmetry, and it makes it clear that the first argument determines the
+;; representation (and key constraints, etc).
+
 (define (dict-union
          #:combine [combine #f]
          #:combine/key [combine/key

collects/unstable/pretty.rkt

@@ -14,3 +14,7 @@
 (define pretty-format/write (pretty-format/pretty pretty-write))
 (define pretty-format/display (pretty-format/pretty pretty-display))
 (define pretty-format/print (pretty-format/pretty pretty-print))
+
+;; Ryan: There doesn't seem to be any 'format' going on. Perhaps call
+;; them pretty-write-to-string, etc?
+;; Bleh, just saw pretty-format in racket/pretty :(

collects/unstable/scribblings/contract.scrbl

@@ -7,8 +7,21 @@
 
 @unstable-header[]
 
-@defthing[non-empty-string/c contract?]{
-Contract for non-empty strings.
+@deftogether[[
+@defproc[(non-empty-string? [x any/c]) boolean?]
+@defproc[(non-empty-list? [x any/c]) boolean?]
+@defproc[(non-empty-bytes? [x any/c]) boolean?]
+@defproc[(non-empty-vector? [x any/c]) boolean?]]]{
+
+Returns @racket[#t] if @racket[x] is of the appropriate data type
+(string, list, bytes, or vector, respectively) and is not empty;
+returns @racket[#f] otherwise.
+}
+
+@defproc[(singleton-list? [x any/c]) boolean?]{
+
+Returns @racket[#t] if @racket[x] is a list of one element; returns
+@racket[#f] otherwise.
 }
 
 @defthing[port-number? contract?]{

collects/web-server/http/redirect.rkt

@@ -25,7 +25,7 @@
 
 (provide/contract
  [redirect-to
-  (->* (non-empty-string/c) (redirection-status? #:headers (listof header?))
+  (->* (non-empty-string?) (redirection-status? #:headers (listof header?))
        response/full?)]
  [redirection-status? (any/c . -> . boolean?)]
  [permanently redirection-status?]