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| -rw-r--r-- | JOURNAL | 79 | ||||
| -rw-r--r-- | NEWS | 6 |
2 files changed, 78 insertions, 7 deletions
@@ -1,9 +1,9 @@ #author Matthias Benkard #date 2007-09-23 - <lisp>(format-time-string "%Y-%m-%d")</lisp> #title Objective-CL Development Diary -#desc News from the Objective-CL lab +#desc Random news from the Objective-CL lab -; Time-stamp: <2008-03-19 12:44:21 mulk> +; Time-stamp: <2008-03-23 12:56:15 mulk> ; ; C-c i t insert-time-stamp ; C-c C-t muse-project-publish-this-file @@ -18,6 +18,81 @@ Context: [[http://matthias.benkard.de/objective-cl][The Objective-CL Project]]. ---- +* 2008-03-21, 21:17:36 CET + +** A Self-Evaluating Form + +**#1=(quote #1#)** + +<example> + +---------------+ + | | + v | + +------+------+ | + | | | | + | | --------+ + | | | | + +--|---+------+ + | + v + QUOTE +</example> + + + +* 2008-03-21, 19:50:17 CET + +** SUPER vs. CALL-NEXT-METHOD + +It just dawned on me that by changing the way +**objective-c-generic-function** dispatch works, it may be possible to give +**call-next-method** a useful semantics. + +Assuming =MLKFnord= is a Lisp-backed Objective-C class which =mulk= is an +instance of, and =MLKSlack= is a Lisp-backed superclass of =MLKFnord=, then +the call =[mulk foo: 10 bar: nil]= is done as follows: + + 1. =MLKFnord's= =foo=:bar: callback is entered. + + 2. The callback calls (#/foo:bar: 'mlk-fnord mulk 10 nil). + + 3. The generic function computes an effective method for these + arguments and calls it. + + 4. The effective method calls **super**. + + 5. **super** causes =MLKSlack's= =foo:bar:= callback to be entered. + + 6. The callback calls =(#/foo:bar: 'mlk-slack mulk 10 nil)=. And so on. + +I'm experimenting with an alternative approach that does away with the +extra class name argument. Here are some random thoughts (which may be +completely wrong), in no particular order: + + * For **call-next-method** to be useful in a multiple inheritance setting, + Objective-C classes must be last in the class precedence list, + because =NSObject's= version of a method will never call **super** and + therefore the call chain will always end there, regardless of what we + do on the Lisp side. + + * A method's definition class must be stored in its method metaobject. + + * A callback needs to call **compute-applicable-methods**, remove all + methods up to the "current" one (which is the first one with the + callback's class as the definition class, that is, the class named by + what is now the artificial class name argument that makes **super** calls + work), and call the form returned by **compute-effective-method** for the + trimmed list of applicable methods. + +The nice thing is that this gives **call-next-method** a meaning that isn't +completely bogus. The bad thing is that it might make method calls +(**call-next-method** and **super**, at least) slow. This new idea is, after +all, way off the usual way of invoking the CLOS dispatch mechanism. + +Note that we could still use normal CLOS generic function dispatch if +the object's class is the same as the callback's definition class. + + * 2008-03-19, 12:38:56 CET ** Evil Microoptimisation @@ -14,13 +14,9 @@ Context: [[http://matthias.benkard.de/objective-cl][The Objective-CL Project]]. ---- -* 0.2.2 (?) +* 0.2.2 (2008-03-23) - CMUCL compatibility has been restored. - - The function IN-METHOD-SYNTAX has been added. It's like - ENABLE-METHOD-SYNTAX except that it does not store the original - syntax to be restored by DISABLE-METHOD-SYNTAX later. Use this for - file-local readtable changes (as opposed to code-block-local ones). - =NSArray= implements the generic sequence protocol on SBCL. - Initialisation behaviour has changed on GNUstep. This should fix some potential crashes related to =NSBundle=. |