C. Queinnec. Designing MEROON V3. In Workshop on Object-Oriented Programming in Lisp, 1993.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....the packed encoding, the bit packed encoding and the compact encoding. We describe how they are computed and how they are used to implement constant time tests. The packed encoding extends to multiple subtyping an algorithm rst described by Cohen [3] and rediscovered independently by Queinnec [13]. When multiple subtyping is not used our solution is the same as Cohen s. We improve on the runtime performance of tests by removing a bound check advocated by Cohen. The code sequence that implements the type test is short enough to be inlined and thus avoid the cost of an extra call. The ....

C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A report on the ECOOP'93 Workshop, September 1993.

....and reals) However, Bigloo implements numerous extensions: support for lexical and syntactic analysis, pattern matching, an exception mechanism, a foreign interface and a module language. The recent Bigloo versions o ers a new extension with an object layer, to a great extent inspired by Meroon [8] of C. Queinnec. The term object oriented is a rather loose tting description that has been pre xed to a number of very di erent languages and systems over the years. We will restrict our attention to two object models: the Smalltalk model [5] where methods are associated to classes and the ....

C. Queinnec. Designing meroon v3. In Workshop on Object-Oriented Programming in Lisp, 1993.

....must also be independent of the set of primitives of the language: Bigloo s library has been designed to be easily modified when changing the source language. This technique has already been used to turn Bigloo into a compiler for various functional languages: ML [18, 19] Scheme [16] Meroon [10]; a preprocessor for the Dylan language [2] is on the way. The compilers obtained by adding these preprocessors to Bigloo are efficient, and in each case, they compare favorably to the best compilers specialized to the source language. Bigloo is also highly portable: it virtually exists on every ....

C. Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, Sankt Augustin (Germany), September 1993.

....the packed encoding, the bit packed encoding and the compact encoding. We describe how they are computed and how they are used to implement constant time tests. The packed encoding extends to multiple subtyping an algorithm first described by Cohen [3] and rediscovered independently by Queinnec [13]. When multiple subtyping is not used our solution is the same as Cohen s. We improve on the runtime performance of tests by removing a bound check advocated by Cohen. The code sequence that implements the type test is short enough to be inlined and thus avoid the cost of an extra call. The ....

C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A report on the ECOOP'93 Workshop, September 1993.

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C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), Sept. 1993.

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C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), Sept. 1993.

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C. Queinnec. Designing meroon v3. In J. Kopp, H. Hohl, and H. Bretthauer, editors, Proceedings of the ECOOP'93 Workshop on Object-Oriented Programming in Lisp: Languages and Applications, September 1993.

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C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), Sept. 1993.

....answers incorrectly) the HTML fields are pre filled with their former content. It is also possible to blank those fields if required. We chose to represent questions as objects with fields and methods. Here are the signatures of the methods on the question objects. They are given in a Meroon [5] style (although the current implementation uses message passing rather than Meroon itself) define method (id (question) returns the identifier (a string) define method (author (question) returns the author (a string) define method (reset (question) erases all already filled ....

C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), Sept. 1993.

....answers incorrectly) the HTML fields are pre filled with their former content. It is also possible to blank those fields if required. We chose to represent questions as objects with fields and methods. Here are the signatures of the methods on the question objects. They are given in a Meroon [5] style (although the current implementation uses message passing rather than Meroon itself) define method (id (question) returns the identifier (a string) define method (author (question) returns the author (a string) define method (reset (question) erases all already filled ....

C. Queinnec. Designing MEROON v3. In C. Rathke, J. Kopp, H. Hohl, and H. Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), Sept. 1993.

....DMeroon data model is particularly comfortable since, in addition to regular records (dotted pairs for example) it allows to express vectors (sequences of references) or strings (sequences of characters) as regular classes and not as special primitive non subclassable classes. The Icslas language [Que93] is entirely supported by the DMeroon data model and therefore does not hide the structure of its basic values. DMeroon s API offers some accessors. It is possible to determine the length of an indexed field, to read a regular or indexed field (the latter must mention a correct index) and to ....

....is so high that mutability must be kept to a minimumand clearly, initialization is not a mutation. Moreover since DMeroon only deals with data, the initialization protocol cannot be based on procedures which are not DMeroon objects. Finally the solution must also solve the co instantiation problem [Que93] i.e. the allocation of mutually referencing objects without mutable fields. The solution is very crude. A raw allocator exists that takes the lengths of the indexed fields and returns an object with unspecified fields content (but specified structure) Such an object is considered to be under ....

Christian Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), September 1993.

....function (the printing generic function, for instance) may enrich it with new methods thus forcing some coherency protocol to run and update the view these users have of this generic function. To avoid this tremendous cost, we adopt a more purely functional point of view (already suggested in [Que93] generic functions are immutable, therefore, adding a method to a generic function yields a new, di erent, enriched generic function. In order to share a generic function with all the methods that may potentially be adjoined later on, one may update the variable that held the former generic ....

....Feature The call next method of CLOS allows a method to invoke the next most speci c method of the current generic function. This special form may only appear within a method special form. The notion of the next most speci c method is well de ned if, as in Cecil [Cha92] or MeroonV3 [Que93] con icting multi methods are detected when added. We propose another feature named call former method that corresponds to a di erent walk of methods. Let us show this feature in action. Continuing our running example, suppose we want to trace the evaluation of sequences: we may change the ....

Christian Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP '93 Workshop, number 788, Sankt Augustin (Germany), September 1993.

....function (the printing generic function, for instance) may enrich it with new methods thus forcing some coherency protocol to run and update the view these users have of this generic function. To avoid this tremendous cost, we adopt a more purely functional point of view (already suggested in [Que93] generic functions are immutable, therefore, adding a method to a generic function yields a new, different, enriched generic function. In order to share a generic function with all the methods that may potentially be adjoined later on, one may update the variable that held the former generic ....

....of CLOS allows a method to invoke the next most specific method of the current generic function. This special form may only appear within a method special form (unlike EuLisp [PNB93] The notion of the next most specific method is well defined if, as in Cecil [Cha92] or MeroonV3 [Que93] conflicting multi methods are detected when added. We propose another feature named call former method that corresponds to a different walk of methods. Let us show this feature in action. Continuing our running example, suppose we want to trace the evaluation of sequences: we may change the ....

Christian Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), September 1993.

....coupled computers, the laziness of its protocols allows it to easily cope with shortterm communication failures provided no message is lost. Since Icslas belong to the Lisp family of dialects, it has all its usual features: macros, high order functions, dynamic evaluation, objects and classes [Que93] interactive debugging tools written in Lisp etc. ....

Christian Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), September 1993.

....Site B Site A husk exit item entry item Figure 3: Making local a distal object There is actually a single class of mutable objects, called Box, that is used to implement mutable variables and mutable object slots. Great care is taken in Icslas to make the user conscious of the (im)mutability [Que93b] of the manipulated data. Maintaining coherency among the replicated copies of mutable objects is dealt with in section 3. We finally adopted the grammar of figure 4 for our implementation language. This grammar ensures that evaluation steps are atomic i.e. can always be run in a bounded and ....

Christian Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), September 1993.

..... are ranked by prefix order, then methods c is just the j th method of the xif node where j = c.number Gamma class.number. Alas, this solution does not resist the introduction of new classes that requires to renumber classes in prefix order (even if that renumbering may be limited as in [Que93] and to reorder the methods within all xif nodes. A (0) B (0 1) C (0 2) D (0 2 3) E (0 2 6) F (0 2 6 9) G (0 2 6 10) H (0 2 8) I (0 2 8 11) J (0 4) K (0 4 5) L (0 4 7) Fig. 2. A numbered inheritance tree of classes Let s then suppose that a class is numbered with respect to ....

....and single dispatch may number classes according to our scheme and use a dispatch structure for method selection based on decision trees respecting the class inheritance tree. The depth of these decision trees allow to control the speed space ratio. This scheme has been implemented in Meroon [Que93] an object system for the Scheme programming language. 7 Acknowledgments The original class numbering scheme was discovered during a stay at University of Montreal in summer 1994. Thanks to Jan Vitek for his encouragement. ....

Christian Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, ObjectOriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, number 788, Sankt Augustin (Germany), September 1993.

No context found.

C. Queinnec. Designing MEROON V3. In Workshop on Object-Oriented Programming in Lisp, 1993.

No context found.

C. Queinnec. Designing meroon v3. In Christian Rathke, Jurgen Kopp, Hubertus Hohl, and Harry Bretthauer, editors, Object-Oriented Programming in Lisp: Languages and Applications. A Report on the ECOOP'93 Workshop, Sankt Augustin (Germany), September 1993.

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