MCL V1.3 To V2.0 Comparison Slides

® Laura Clark Development Tools Product Marketing Lisp Product Marketing Manager ® Macintosh Allegro Common Lisp Update Overview What You Expect in a Powerful Lisp Environment . . . • Full Common Lisp • EMACS-style editor • Inspector • Debugging tools • Lisp Listener What You Want in a Macintosh Development Environment . . . • Fast, compact compiler • High-level access to the toolbox • Object library defines windows, dialogs, and menus • Interactive interface designer Why Lisp? • Interactive • Dynamic • Memory management • Run-time error handling • Object technology Macintosh Allegro CL v.1.3.2 • Released in April 1990 • Interface designer with source • Programmable grapher with source • Windoids • FFI support MPW 3.0 object files • Color dialogs and menus In the Future • System 7.0 support – Virtual Memory – AppleEvents • Ephemeral GC • CLOS • Steele second edition compatibility • Small applications ® Bill St. Clair Macintosh Allegro Common Lisp Lisp Hacker - ATG Cambridge ® Macintosh Allegro Common Lisp Update What’s new in MACL 2.0 Technical Details MACL 2.0–New Features • CLtL2 compatible (186 cleanup issues) • CLOS replaces Object-Lisp • New representation – 32-bit clean, VM, dynamic-extent • Views replace Dialogs • New inspector and debugger Common Lisp Object System Slide: CBC Text 1 Common Lisp • CLOS is the standard • Seamlessly integrated – Generic functions behave just like regular functions – Classes are part of the type system • Featureful (and then some) Object System • Class/Instance paradigm • Instance “slots” for local state • Class “slots” for shared state • Methods provide specialized behavior for generic functions • Multiple inheritance Object-Lisp • Prototype/Instance paradigm • Local variables for local state • Inherited variables for shared state • Object functions provide specialized behavior • Multiple inheritance • Object-Lisp is dead. Long live CLOS. Object-Lisp => CLOS • defobject + exist => defclass + initialize-instance • defobfun => defmethod (automatic) • object-var => (slot-value ...) • (ask instance (f x y)) => (f instance x y) • usual-xxx => call-next-method Statistics 1.3 2.0 2.0 OL CLOS PCL 1.3 2.0 Function-call 8 3 9 2 1 Slot-value 21 11 41 1 1 Accessor 21 18 23 1 1 Make-instance 1.6 1 8-50 Instance size 4N+8 N+3 N+6 System size 16K 200K 1M New Representation • BBOP => low-bits tag • Stack-consed (downward) closures • Dynamic-extent • Ephemeral gc • Virtual memory: copying gc BBOP (Big Bag of Pages) F Page Offset Type Memory Page Table Low-Bits Tag Pointer Tag 000 Fixnum 001 Vector 010 Symbol 011 Float 100 Cons 101 Reserved Memory 110 Lfun 111 Immediate…