minor tweaks to web documentation

* doc/ref/web.texi: Say `World Wide Web'; the hyphenated form is almost
  never used (c.f. w3.org).

  General predicate arguments are named `obj'.  Fill in arguments
  omitted from some procedure definitions (e.g. `request-method').

  Minor tweaks, such as using en-dash and missing markup as appropriate.
  Wrap very long deffn lines.

* module/web/*.scm: Expand texinfo markup in doc strings.  Synchronize
  with changes in web.texi.

module/web/client.scm

@@ -248,10 +248,10 @@ pass it as PORT.  The port will be closed at the end of the
 request unless KEEP-ALIVE? is true.  Any extra headers in the
 alist HEADERS will be added to the request.
 
-If BODY is not #f, a message body will also be sent with the HTTP
+If BODY is not ‘#f’, a message body will also be sent with the HTTP
 request.  If BODY is a string, it is encoded according to the
 content-type in HEADERS, defaulting to UTF-8.  Otherwise BODY should be
-a bytevector, or #f for no body.  Although it's allowed to send a
+a bytevector, or ‘#f’ for no body.  Although it's allowed to send a
 message body along with any request, usually only POST and PUT requests
 have bodies.  See ‘http-put’ and ‘http-post’ documentation, for more.
 
@@ -317,7 +317,7 @@ This function is similar to ‘http-get’, except it uses the \"HEAD\"
 method.  See ‘http-get’ for full documentation on the various keyword
 arguments that are accepted by this function.
 
-Returns two values: the resulting response, and #f.  Responses to HEAD
+Returns two values: the resulting response, and ‘#f’.  Responses to HEAD
 requests do not have a body.  The second value is only returned so that
 other procedures can treat all of the http-foo verbs identically.")
 

module/web/http.scm

@@ -167,7 +167,7 @@ The default writer is ‘display’."
 (define *eof* (call-with-input-string "" read))
 
 (define (read-header port)
-  "Reads one HTTP header from PORT. Returns two values: the header
+  "Read one HTTP header from PORT. Return two values: the header
 name and the parsed Scheme value. May raise an exception if the header
 was known but the value was invalid.
 
@@ -220,7 +220,7 @@ as an ordered alist."
 
 (define (write-headers headers port)
   "Write the given header alist to PORT.  Doesn't write the final
-@samp{\\r\\n}, as the user might want to add another header."
+‘\\r\\n’, as the user might want to add another header."
   (let lp ((headers headers))
     (if (pair? headers)
         (begin
@@ -971,7 +971,7 @@ as an ordered alist."
 (define *known-versions* '())
 
 (define* (parse-http-version str #:optional (start 0) (end (string-length str)))
-  "Parse an HTTP version from STR, returning it as a major-minor
+  "Parse an HTTP version from STR, returning it as a major–minor
 pair. For example, ‘HTTP/1.1’ parses as the pair of integers,
 ‘(1 . 1)’."
   (or (let lp ((known *known-versions*))

module/web/response.scm

@@ -267,10 +267,10 @@ closes PORT, unless KEEP-ALIVE? is true."
 (define* (response-body-port r #:key (decode? #t) (keep-alive? #t))
   "Return an input port from which the body of R can be read.  The
 encoding of the returned port is set according to R's ‘content-type’
-header, when it's textual, except if DECODE? is #f.  Return #f when no
-body is available.
+header, when it's textual, except if DECODE? is ‘#f’.  Return #f when
+no body is available.
 
-When KEEP-ALIVE? is #f, closing the returned port also closes R's
+When KEEP-ALIVE? is ‘#f’, closing the returned port also closes R's
 response port."
   (define port
     (cond

module/web/uri.scm

@@ -53,8 +53,8 @@
   (query uri-query)
   (fragment uri-fragment))
 
-(define (absolute-uri? x)
-  (and (uri? x) (uri-scheme x) #t))
+(define (absolute-uri? obj)
+  (and (uri? obj) (uri-scheme obj) #t))
 
 (define (uri-error message . args)
   (throw 'uri-error message args))
@@ -309,17 +309,16 @@ serialization."
 which should be the name of a character encoding.
 
 Note that this function should not generally be applied to a full URI
-string. For paths, use split-and-decode-uri-path instead. For query
+string. For paths, use ‘split-and-decode-uri-path’ instead. For query
 strings, split the query on ‘&’ and ‘=’ boundaries, and decode
 the components separately.
 
-Note also that percent-encoded strings encode @emph{bytes}, not
-characters.  There is no guarantee that a given byte sequence is a valid
-string encoding. Therefore this routine may signal an error if the
-decoded bytes are not valid for the given encoding. Pass ‘#f’ for
-ENCODING if you want decoded bytes as a bytevector directly.
-@xref{Ports, ‘set-port-encoding!’}, for more information on
-character encodings.
+Note also that percent-encoded strings encode _bytes_, not characters.
+There is no guarantee that a given byte sequence is a valid string
+encoding. Therefore this routine may signal an error if the decoded
+bytes are not valid for the given encoding. Pass ‘#f’ for ENCODING if
+you want decoded bytes as a bytevector directly.  ‘set-port-encoding!’,
+for more information on character encodings.
 
 Returns a string of the decoded characters, or a bytevector if
 ENCODING was ‘#f’."
@@ -380,11 +379,10 @@ ENCODING was ‘#f’."
 UNESCAPED-CHARS.
 
 The default character set includes alphanumerics from ASCII, as well as
-the special characters @samp{-}, @samp{.}, @samp{_}, and @samp{~}.  Any
-other character will be percent-encoded, by writing out the character to
-a bytevector within the given ENCODING, then encoding each byte as
-‘%HH’, where HH is the hexadecimal representation of
-the byte."
+the special characters ‘-’, ‘.’, ‘_’, and ‘~’.  Any other character will
+be percent-encoded, by writing out the character to a bytevector within
+the given ENCODING, then encoding each byte as ‘%HH’, where HH is the
+hexadecimal representation of the byte."
   (define (needs-escaped? ch)
     (not (char-set-contains? unescaped-chars ch)))
   (if (string-index str needs-escaped?)