Difference between revisions of "ECL/Wrapping constants"


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(Created page with "{{ECL/experiments message}} == Documentation / References == * [http://sourceforge.net/mailarchive/message.php?msg_id=31157657 Thread at ecls-list: Wrapping C++ constants......")
 
 
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{{ECL/experiments message}}
 
{{ECL/experiments message}}
  
−
== Documentation / References ==
+
= Example =
  
−
* [http://sourceforge.net/mailarchive/message.php?msg_id=31157657 Thread at ecls-list: Wrapping C++ constants...]
+
DEFCONSTANT has to be wrapped into a LET block:
  
−
=== Examples ===
+
Example:
  
−
DEFCONSTANT have to be wrapped into a LET block:
+
<pre>
 +
(ffi:clines "#define SOME_CONSTANT 123")
 +
(let () (defconstant +some-constant+ (ffi:c-inline () () :int "SOME_CONSTANT" :one-liner t)))
 +
</pre>
 +
 
 +
Usage:
  
 
<pre>
 
<pre>
−
todo
+
(format t "+some-constant+: ~a~%" +some-constant+)
 
</pre>
 
</pre>
  
−
Using them on the top-level results in an error being thrown.
+
Output:
  
−
==== Examples from [http://sourceforge.net/p/ecls/ecl/ci/master/tree/contrib/sockets/sockets.lisp contrib/sockets/sockets.lisp] ====
+
<pre>
 +
+some-constant+: 123
 +
</pre>
 +
 
 +
 
 +
Using DEFCONSTANT on the top-level
 +
 
 +
<pre>
 +
(ffi:clines "#define SOME_CONSTANT 123")
 +
(defconstant +some-constant+ (ffi:c-inline () () :int "SOME_CONSTANT" :one-liner t))
 +
</pre>
 +
 
 +
results in an error being thrown:
 +
 
 +
<pre>
 +
;;; Error:
 +
;;;  in file rhino-lisp-api.lisp, position 42
 +
;;;  at (DEFCONSTANT +SOME-CONSTANT+ ...)
 +
;;;  * The form (PROGN (SI:*MAKE-CONSTANT '+SOME-CONSTANT+ (FFI:C-INLINE NIL NIL :INT "SOME_CONSTANT" :ONE-LINER T)) (SI::REGISTER-GLOBAL '+SOME-CONSTANT+)) was not evaluated successfully.
 +
;;; Error detected:
 +
;;; The special form c-inline cannot be used in the interpreter: (NIL NIL INT SOME_CONSTANT ONE-LINER T)An error occurred during initialization:
 +
COMPILE-FILE-ERROR while
 +
compiling #<cl-source-file "rhino-lisp-api" "rhino-lisp-api">.
 +
NMAKE : fatal error U1077: 'C:\Users\dietrich\home\cs\lang\lisp\ecl\64\git\install\ecl.exe' : return code '0x1'
 +
Stop.
 +
</pre>
 +
 
 +
 
 +
= Documentation / References =
 +
 
 +
* [http://sourceforge.net/mailarchive/message.php?msg_id=31157657 Thread at ecls-list: Wrapping C++ constants...]
 +
 
 +
 
 +
= Other examples from [http://sourceforge.net/p/ecls/ecl/ci/master/tree/contrib/sockets/sockets.lisp contrib/sockets/sockets.lisp] =
  
 
* [http://sourceforge.net/p/ecls/ecl/ci/master/tree/contrib/sockets/sockets.lisp#l92]
 
* [http://sourceforge.net/p/ecls/ecl/ci/master/tree/contrib/sockets/sockets.lisp#l92]
  
 
<pre>
 
<pre>
−
todo
+
(eval-when (:compile-toplevel :execute)
 +
  (defmacro c-constant (c-name)
 +
    `(c-inline () () :int ,c-name :one-liner t))
 +
  (defmacro define-c-constants (&rest args)
 +
    `(let () ; Prevents evaluation of constant value form
 +
      ,@(loop
 +
    for (lisp-name c-name) on args by #'cddr
 +
    collect `(defconstant ,lisp-name (c-constant ,c-name))))))
 
</pre>
 
</pre>
  
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<pre>
 
<pre>
−
todo
+
(define-c-constants
 +
  +af-inet+ "AF_INET"
 +
  +af-local+ #-sun4sol2 "AF_LOCAL" #+sun4sol2 "AF_UNIX"
 +
  +eagain+ "EAGAIN"
 +
  +eintr+ "EINTR")
 +
</pre>
 +
 
 +
* [http://sourceforge.net/p/ecls/ecl/ci/master/tree/contrib/sockets/sockets.lisp#l1352]
 +
 
 +
<pre>
 +
(defmacro define-socket-condition (symbol name)
 +
  `(let () ; Prevents evaluation of constant value at compilation time
 +
    (defconstant ,symbol (c-constant ,(symbol-name symbol)))
 +
    (define-condition ,name (socket-error)
 +
      ((symbol :reader socket-error-symbol :initform (quote ,symbol))))
 +
    (export ',name)
 +
    (push (cons ,symbol (quote ,name)) *conditions-for-errno*)))
 
</pre>
 
</pre>
  
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<pre>
 
<pre>
−
todo
+
(defmacro define-name-service-condition (symbol name)
 +
  `(let ()
 +
    (defconstant ,symbol (c-constant ,(symbol-name symbol)))
 +
    (define-condition ,name (name-service-error)
 +
      ((symbol :reader name-service-error-symbol :initform (quote ,symbol))))
 +
    (push (cons ,symbol (quote ,name)) *conditions-for-name-service-errno*)
 +
    (export (quote ,symbol))))
 
</pre>
 
</pre>

Latest revision as of 04:44, 12 July 2013

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