X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftype-class.lisp;h=ae34c2681ec730f13816a312debc74c01e8ecd91;hb=f143939b1dbaf38ebd4f92c851fbc4ecddf37af1;hp=5562e1a1ecb5de1bbb91e7b961d99669db219a4a;hpb=8624c52d7620e8a4d3de23c363e843a10815f4f4;p=sbcl.git diff --git a/src/code/type-class.lisp b/src/code/type-class.lisp index 5562e1a..ae34c26 100644 --- a/src/code/type-class.lisp +++ b/src/code/type-class.lisp @@ -26,9 +26,10 @@ (/show0 "failing in MUST-SUPPLY-THIS") (error "missing type method for ~S" foo)) -;;; A TYPE-CLASS object represents the "kind" of a type. It mainly contains -;;; functions which are methods on that kind of type, but is also used in EQ -;;; comparisons to determined if two types have the "same kind". +;;; A TYPE-CLASS object represents the "kind" of a type. It mainly +;;; contains functions which are methods on that kind of type, but is +;;; also used in EQ comparisons to determined if two types have the +;;; "same kind". (def!struct (type-class #-no-ansi-print-object (:print-object (lambda (x stream) @@ -53,16 +54,35 @@ (simple-subtypep #'must-supply-this :type function) (complex-subtypep-arg1 nil :type (or function null)) (complex-subtypep-arg2 nil :type (or function null)) - ;; SIMPLE-UNION combines two types of the same class into a single - ;; type of that class. If the result is a two-type union, then - ;; return NIL. VANILLA-UNION returns whichever argument is a - ;; supertype of the other, or NIL. - (simple-union #'vanilla-union :type function) - (complex-union nil :type (or function null)) - ;; The default intersection methods assume that if one type is a - ;; subtype of the other, then that type is the intersection. - (simple-intersection #'vanilla-intersection :type function) - (complex-intersection nil :type (or function null)) + ;; SIMPLE-UNION2, COMPLEX-UNION2, SIMPLE-INTERSECTION2, and + ;; COMPLEX-INTERSECTION2 methods take pairs of types and try to find + ;; a new type which expresses the result nicely, better than could + ;; be done by just stuffing the two component types into an + ;; UNION-TYPE or INTERSECTION-TYPE object. They return NIL on + ;; failure, or a CTYPE for success. + ;; + ;; Note: These methods are similar to CMU CL's SIMPLE-UNION, + ;; COMPLEX-UNION, SIMPLE-INTERSECTION, and COMPLEX-UNION methods. + ;; They were reworked in SBCL because SBCL has INTERSECTION-TYPE + ;; objects (where CMU CL just punted to HAIRY-TYPE) and because SBCL + ;; wants to simplify unions and intersections by considering all + ;; possible pairwise simplifications (where the CMU CL code only + ;; considered simplifications between types which happened to appear + ;; next to each other the argument sequence). + ;; + ;; Differences in detail from old CMU CL methods: + ;; * SBCL's methods are more parallel between union and + ;; intersection forms. Each returns one values, (OR NULL CTYPE). + ;; * SBCL doesn't use type methods to deal with unions or + ;; intersections of the COMPOUND-TYPE of the corresponding form. + ;; Instead the wrapper functions TYPE-UNION2, TYPE-INTERSECTION2, + ;; TYPE-UNION, and TYPE-INTERSECTION handle those cases specially + ;; (and deal with canonicalization/simplification issues at the + ;; same time). + (simple-union2 #'hierarchical-union2 :type function) + (complex-union2 nil :type (or function null)) + (simple-intersection2 #'hierarchical-intersection2 :type function) + (complex-intersection2 nil :type (or function null)) (simple-= #'must-supply-this :type function) (complex-= nil :type (or function null)) ;; a function which returns a Common Lisp type specifier @@ -88,54 +108,59 @@ ) (eval-when (:compile-toplevel :load-toplevel :execute) + ;; KLUDGE: If the slots of TYPE-CLASS ever change, the slots here + ;; will have to be tweaked to match. -- WHN 19991021 + (defparameter *type-class-fun-slots* + '((:simple-subtypep . type-class-simple-subtypep) + (:complex-subtypep-arg1 . type-class-complex-subtypep-arg1) + (:complex-subtypep-arg2 . type-class-complex-subtypep-arg2) + (:simple-union2 . type-class-simple-union2) + (:complex-union2 . type-class-complex-union2) + (:simple-intersection2 . type-class-simple-intersection2) + (:complex-intersection2 . type-class-complex-intersection2) + (:simple-= . type-class-simple-=) + (:complex-= . type-class-complex-=) + (:unparse . type-class-unparse)))) -;;; Copy TYPE-CLASS object X, using only operations which will work early in -;;; cold load. (COPY-STRUCTURE won't work early in cold load, because it needs -;;; RAW-INDEX and RAW-LENGTH information from LAYOUT-INFO, and LAYOUT-INFO -;;; isn't initialized early in cold load.) +(eval-when (:compile-toplevel :load-toplevel :execute) + +;;; Copy TYPE-CLASS object X, using only operations which will work +;;; early in cold load. (COPY-STRUCTURE won't work early in cold load, +;;; because it needs RAW-INDEX and RAW-LENGTH information from +;;; LAYOUT-INFO, and LAYOUT-INFO isn't initialized early in cold +;;; load.) ;;; -;;; FIXME: It's nasty having to maintain this hand-written copy function. And -;;; it seems intrinsically dain-bramaged to have RAW-INDEX and RAW-LENGTH in -;;; LAYOUT-INFO instead of directly in LAYOUT. We should fix this: * Move -;;; RAW-INDEX and RAW-LENGTH slots into LAYOUT itself. * Rewrite the various -;;; CHECK-LAYOUT-related functions so that they check RAW-INDEX and RAW-LENGTH -;;; too. * Remove this special hacked copy function, just use COPY-STRUCTURE -;;; instead. (For even more improvement, it'd be good to move the raw slots +;;; FIXME: It's nasty having to maintain this hand-written copy +;;; function. And it seems intrinsically dain-bramaged to have +;;; RAW-INDEX and RAW-LENGTH in LAYOUT-INFO instead of directly in +;;; LAYOUT. We should fix this: +;;; * Move RAW-INDEX and RAW-LENGTH slots into LAYOUT itself. +;;; * Rewrite the various CHECK-LAYOUT-related functions so that +;;; they check RAW-INDEX and RAW-LENGTH too. +;;; * Remove this special hacked copy function, just use +;;; COPY-STRUCTURE instead. +;;; (For even more improvement, it might be good to move the raw slots ;;; into the same object as the ordinary slots, instead of having the -;;; unfortunate extra level of indirection. But that'd probably require a lot -;;; of work, including updating the garbage collector to understand it.) +;;; unfortunate extra level of indirection. But that'd probably +;;; require a lot of work, including updating the garbage collector to +;;; understand it. And it might even hurt overall performance, because +;;; the positive effect of removing indirection could be cancelled by +;;; the negative effect of imposing an unnecessary GC write barrier on +;;; raw data which doesn't actually affect GC.) (declaim (ftype (function (type-class) type-class) copy-type-class-coldly)) (defun copy-type-class-coldly (x) - ;; KLUDGE: If the slots of TYPE-CLASS ever change, the slots here will have - ;; to be hand-tweaked to match. -- WHN 19991021 - (make-type-class :name (type-class-name x) - :simple-subtypep (type-class-simple-subtypep x) - :complex-subtypep-arg1 (type-class-complex-subtypep-arg1 x) - :complex-subtypep-arg2 (type-class-complex-subtypep-arg2 x) - :simple-union (type-class-simple-union x) - :complex-union (type-class-complex-union x) - :simple-intersection (type-class-simple-intersection x) - :complex-intersection (type-class-complex-intersection x) - :simple-= (type-class-simple-= x) - :complex-= (type-class-complex-= x) - :unparse (type-class-unparse x))) - -;;; KLUDGE: If the slots of TYPE-CLASS ever change, the slots here -;;; will have to be tweaked to match. -- WHN 19991021 -(defparameter *type-class-function-slots* - '((:simple-subtypep . type-class-simple-subtypep) - (:complex-subtypep-arg1 . type-class-complex-subtypep-arg1) - (:complex-subtypep-arg2 . type-class-complex-subtypep-arg2) - (:simple-union . type-class-simple-union) - (:complex-union . type-class-complex-union) - (:simple-intersection . type-class-simple-intersection) - (:complex-intersection . type-class-complex-intersection) - (:simple-= . type-class-simple-=) - (:complex-= . type-class-complex-=) - (:unparse . type-class-unparse))) - -(defun class-function-slot-or-lose (name) - (or (cdr (assoc name *type-class-function-slots*)) + ;; KLUDGE: If the slots of TYPE-CLASS ever change in a way not + ;; reflected in *TYPE-CLASS-FUN-SLOTS*, the slots here will + ;; have to be hand-tweaked to match. -- WHN 2001-03-19 + (make-type-class :name (type-class-name x) + . #.(mapcan (lambda (type-class-fun-slot) + (destructuring-bind (keyword . slot-accessor) + type-class-fun-slot + `(,keyword (,slot-accessor x)))) + *type-class-fun-slots*))) + +(defun class-fun-slot-or-lose (name) + (or (cdr (assoc name *type-class-fun-slots*)) (error "~S is not a defined type class method." name))) ;;; FIXME: This seems to be called at runtime by cold init code. ;;; Make sure that it's not being called at runtime anywhere but @@ -151,7 +176,7 @@ ,@body) (!cold-init-forms ,@(mapcar (lambda (method) - `(setf (,(class-function-slot-or-lose method) + `(setf (,(class-fun-slot-or-lose method) (type-class-or-lose ',class)) #',name)) (cons method more-methods))) @@ -173,17 +198,25 @@ ;;; complex method. If there isn't a distinct COMPLEX-ARG1 method, ;;; then swap the arguments when calling TYPE1's method. If no ;;; applicable method, return DEFAULT. +;;; +;;; KLUDGE: It might be a lot easier to understand this and the rest +;;; of the type system code if we used CLOS to express it instead of +;;; trying to maintain this squirrely hand-crufted object system. +;;; Unfortunately that'd require reworking PCL bootstrapping so that +;;; all the compilation can get done by the cross-compiler, which I +;;; suspect is hard, so we'll bear with the old system for the time +;;; being. -- WHN 2001-03-11 (defmacro !invoke-type-method (simple complex-arg2 type1 type2 &key (default '(values nil t)) (complex-arg1 :foo complex-arg1-p)) (declare (type keyword simple complex-arg1 complex-arg2)) `(multiple-value-bind (result-a result-b valid-p) - (%invoke-type-method ',(class-function-slot-or-lose simple) - ',(class-function-slot-or-lose + (%invoke-type-method ',(class-fun-slot-or-lose simple) + ',(class-fun-slot-or-lose (if complex-arg1-p complex-arg1 complex-arg2)) - ',(class-function-slot-or-lose complex-arg2) + ',(class-fun-slot-or-lose complex-arg2) ,complex-arg1-p ,type1 ,type2)