Custom Query (1030 matches)

Subject line says it all. This is technically not incorrect behavior, but given that (listen) does something different on *standard-input* than it does for other streams (like file streams and TCP streams) it would be nice to have a way to test which behavior to expect before calling (listen).

Per the discussion on the mailing list I request that support for a user hook for ((...) ...) syntax be added to CCL. A reference implementation can be found here:

​http://www.flownet.com/ron/lisp/nx1-combination-hook.lisp

SLSIA. Here's an example:

Welcome to Clozure Common Lisp Version 1.5-dev-r13442M-trunk  (DarwinX8664)!
? (#/title (car (gui::windows)))
#<NS-MUTABLE-STRING "Listener" (#x1D03B0)>
? (set-macro-character #\e (lambda (stream char) char) t)
;Compiler warnings :
;   In an anonymous lambda form at position 25: Unused lexical variable STREAM
T
? (#/title (car (gui::windows)))
> Error: Undefined function NEXTSTEP-FUNCTIONS:|titl| called with arguments (#\e #<HEMLOCK-LISTENER-FRAME <HemlockListenerFrame: 0x1cd640> (#x1CD640)>) .

Here's the fix:

(set-dispatch-macro-character #\# #\/
  (let ((rt (copy-readtable nil)))
    (lambda (stream subchar numarg)
      (declare (ignorable subchar numarg))
      (let* ((token (make-array 16 :element-type 'character :fill-pointer 0 :adjustable t))
             (attrtab (rdtab.ttab rt)))
        (when (peek-char t stream nil nil)
          (loop
            (multiple-value-bind (char attr)
                                 (%next-char-and-attr stream attrtab)
              (unless (eql attr $cht_cnst)
                (when char (unread-char char stream))
                (return))
              (vector-push-extend char token))))
        (unless *read-suppress*
          (unless (> (length token) 0)
            (signal-reader-error stream "Invalid token after #/."))
          (check-objc-message-name token)
          (intern token "NSFUN"))))))

NOTE: This issue is related to the issue of reader macros affecting the syntax of uninterned symbols, which generate some controversy on the mailing list. In this case, the syntax of objective-C function names is not governed by the ANSI standard, so the controversy is moot.