X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fearly-extensions.lisp;h=61c6404ec8c5591d3389050b4e11d6834ffe30d3;hb=dbfe7e6c8b06e1b0b1ba35d9894fae13e6305602;hp=323982d5ed5b9b9b201ca8690f6eb3f941a451fb;hpb=2217cdb364e8b48c187b085895bb2a5cbdbd9622;p=sbcl.git diff --git a/src/code/early-extensions.lisp b/src/code/early-extensions.lisp index 323982d..61c6404 100644 --- a/src/code/early-extensions.lisp +++ b/src/code/early-extensions.lisp @@ -65,6 +65,20 @@ (* max-offset sb!vm:n-word-bytes)) scale))) +;;; Similar to FUNCTION, but the result type is "exactly" specified: +;;; if it is an object type, then the function returns exactly one +;;; value, if it is a short form of VALUES, then this short form +;;; specifies the exact number of values. +(def!type sfunction (args &optional result) + (let ((result (cond ((eq result '*) '*) + ((or (atom result) + (not (eq (car result) 'values))) + `(values ,result &optional)) + ((intersection (cdr result) lambda-list-keywords) + result) + (t `(values ,@(cdr result) &optional))))) + `(function ,args ,result))) + ;;; the default value used for initializing character data. The ANSI ;;; spec says this is arbitrary, so we use the value that falls ;;; through when we just let the low-level consing code initialize @@ -105,29 +119,6 @@ ;;;; type-ish predicates -;;; a helper function for various macros which expect clauses of a -;;; given length, etc. -(eval-when (:compile-toplevel :load-toplevel :execute) - ;; Return true if X is a proper list whose length is between MIN and - ;; MAX (inclusive). - (defun proper-list-of-length-p (x min &optional (max min)) - ;; FIXME: This implementation will hang on circular list - ;; structure. Since this is an error-checking utility, i.e. its - ;; job is to deal with screwed-up input, it'd be good style to fix - ;; it so that it can deal with circular list structure. - (cond ((minusp max) - nil) - ((null x) - (zerop min)) - ((consp x) - (and (plusp max) - (proper-list-of-length-p (cdr x) - (if (plusp (1- min)) - (1- min) - 0) - (1- max)))) - (t nil)))) - ;;; Is X a list containing a cycle? (defun cyclic-list-p (x) (and (listp x) @@ -146,6 +137,11 @@ (and (consp x) (list-of-length-at-least-p (cdr x) (1- n))))) +(declaim (inline singleton-p)) +(defun singleton-p (list) + (and (consp list) + (null (rest list)))) + ;;; Is X is a positive prime integer? (defun positive-primep (x) ;; This happens to be called only from one place in sbcl-0.7.0, and @@ -184,7 +180,7 @@ ;;; COLLECT-LIST-EXPANDER handles the list collection case. N-TAIL ;;; is the pointer to the current tail of the list, or NIL if the list ;;; is empty. -(eval-when (:compile-toplevel :load-toplevel :execute) +(eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute) (defun collect-normal-expander (n-value fun forms) `(progn ,@(mapcar (lambda (form) `(setq ,n-value (,fun ,form ,n-value))) forms) @@ -323,10 +319,19 @@ (declaim (ftype (function (list index) t) nth-but-with-sane-arg-order)) (defun nth-but-with-sane-arg-order (list index) (nth index list)) + +(defun adjust-list (list length initial-element) + (let ((old-length (length list))) + (cond ((< old-length length) + (append list (make-list (- length old-length) + :initial-element initial-element))) + ((> old-length length) + (subseq list 0 length)) + (t list)))) ;;;; miscellaneous iteration extensions -;;; "the ultimate iteration macro" +;;; "the ultimate iteration macro" ;;; ;;; note for Schemers: This seems to be identical to Scheme's "named LET". (defmacro named-let (name binds &body body) @@ -624,26 +629,7 @@ ;;; Is NAME a legal function name? (defun legal-fun-name-p (name) - (or (symbolp name) - (and (consp name) - ;; (SETF FOO) - ;; (CLASS-PREDICATE FOO) - (or (and (or (eq (car name) 'setf) - (eq (car name) 'sb!pcl::class-predicate)) - (consp (cdr name)) - (symbolp (cadr name)) - (null (cddr name))) - ;; (SLOT-ACCESSOR - ;; [READER|WRITER|BOUNDP]) - (and (eq (car name) 'sb!pcl::slot-accessor) - (consp (cdr name)) - (symbolp (cadr name)) - (consp (cddr name)) - (symbolp (caddr name)) - (consp (cdddr name)) - (member - (cadddr name) - '(sb!pcl::reader sb!pcl::writer sb!pcl::boundp))))))) + (values (valid-function-name-p name))) ;;; Signal an error unless NAME is a legal function name. (defun legal-fun-name-or-type-error (name) @@ -666,11 +652,12 @@ (defun fun-name-block-name (fun-name) (cond ((symbolp fun-name) fun-name) - ((and (consp fun-name) - (legal-fun-name-p fun-name)) - (case (car fun-name) - ((setf sb!pcl::class-predicate) (second fun-name)) - ((sb!pcl::slot-accessor) (third fun-name)))) + ((consp fun-name) + (multiple-value-bind (legalp block-name) + (valid-function-name-p fun-name) + (if legalp + block-name + (error "not legal as a function name: ~S" fun-name)))) (t (error "not legal as a function name: ~S" fun-name)))) @@ -832,12 +819,6 @@ which can be found at .~:@>" :format-string "~@<~S ~_is not a ~_~S~:>" :format-arguments (list value type))) -;;; Return a list of N gensyms. (This is a common suboperation in -;;; macros and other code-manipulating code.) -(declaim (ftype (function (index) list) make-gensym-list)) -(defun make-gensym-list (n) - (loop repeat n collect (gensym))) - ;;; Return a function like FUN, but expecting its (two) arguments in ;;; the opposite order that FUN does. (declaim (inline swapped-args-fun)) @@ -939,6 +920,24 @@ which can be found at .~:@>" ;;;; utilities for two-VALUES predicates +(defmacro not/type (x) + (let ((val (gensym "VAL")) + (win (gensym "WIN"))) + `(multiple-value-bind (,val ,win) + ,x + (if ,win + (values (not ,val) t) + (values nil nil))))) + +(defmacro and/type (x y) + `(multiple-value-bind (val1 win1) ,x + (if (and (not val1) win1) + (values nil t) + (multiple-value-bind (val2 win2) ,y + (if (and val1 val2) + (values t t) + (values nil (and win2 (not val2)))))))) + ;;; sort of like ANY and EVERY, except: ;;; * We handle two-VALUES predicate functions, as SUBTYPEP does. ;;; (And if the result is uncertain, then we return (VALUES NIL NIL), @@ -1084,3 +1083,18 @@ which can be found at .~:@>" `(if ,test (let ((it ,test)) (declare (ignorable it)),@body) (acond ,@rest)))))) + + +;;; Delayed evaluation +(defmacro delay (form) + `(cons nil (lambda () ,form))) + +(defun force (promise) + (cond ((not (consp promise)) promise) + ((car promise) (cdr promise)) + (t (setf (car promise) t + (cdr promise) (funcall (cdr promise)))))) + +(defun promise-ready-p (promise) + (or (not (consp promise)) + (car promise)))