X-Git-Url: https://git.distorted.org.uk/~mdw/lisp/blobdiff_plain/93f0472497372859d9cb9bf7690044bd0e66f0ad..af33e77c00654c222a8a04a5e69a5eb1f56c1e8c:/mdw-base.lisp diff --git a/mdw-base.lisp b/mdw-base.lisp index 72b5b06..a41b685 100644 --- a/mdw-base.lisp +++ b/mdw-base.lisp @@ -13,12 +13,12 @@ ;;; it under the terms of the GNU General Public License as published by ;;; the Free Software Foundation; either version 2 of the License, or ;;; (at your option) any later version. -;;; +;;; ;;; This program is distributed in the hope that it will be useful, ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;;; GNU General Public License for more details. -;;; +;;; ;;; You should have received a copy of the GNU General Public License ;;; along with this program; if not, write to the Free Software Foundation, ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. @@ -28,43 +28,74 @@ (defpackage #:mdw.base (:use #:common-lisp) - (:export #:compile-time-defun + (:export #:unsigned-fixnum + #:compile-time-defun #:show - #:stringify #:listify #:fix-pair #:pairify + #:stringify #:functionify #:mappend + #:listify #:fix-pair #:pairify + #:parse-body #:with-parsed-body #:whitespace-char-p #:slot-uninitialized - #:nlet #:while + #:nlet #:while #:until #:case2 #:ecase2 #:setf-default #:with-gensyms #:let*/gensyms #:with-places #:locp #:locf #:ref #:with-locatives #:update-place #:update-place-after - #:incf-after #:decf-after)) + #:incf-after #:decf-after + #:fixnump) + #+cmu (:import-from #:extensions #:fixnump)) + (in-package #:mdw.base) ;;;-------------------------------------------------------------------------- +;;; Useful types. + +(deftype unsigned-fixnum () + "Unsigned fixnums; useful as array indices and suchlike." + `(mod ,most-positive-fixnum)) + +;;;-------------------------------------------------------------------------- ;;; Some simple macros to get things going. (defmacro compile-time-defun (name args &body body) "Define a function which can be used by macros during the compilation -process." - `(eval-when (:compile-toplevel :load-toplevel) + process." + `(eval-when (:compile-toplevel :load-toplevel :execute) (defun ,name ,args ,@body))) (defmacro show (x) - "Debugging tool: print the expression X and its value." + "Debugging tool: print the expression X and its values." (let ((tmp (gensym))) - `(let ((,tmp ,x)) - (format t "~&~S: ~S~%" ',x ,tmp) - ,tmp))) + `(let ((,tmp (multiple-value-list ,x))) + (format t "~&") + (pprint-logical-block (*standard-output* nil :per-line-prefix ";; ") + (format t + "~S = ~@_~:I~:[#~;~:*~{~S~^ ~_~}~]" + ',x + ,tmp)) + (terpri) + (values-list ,tmp)))) (defun stringify (str) "Return a string representation of STR. Strings are returned unchanged; -symbols are converted to their names (unqualified!). Other objects are -converted to their print representations." + symbols are converted to their names (unqualified!). Other objects are + converted to their print representations." (typecase str (string str) (symbol (symbol-name str)) - (t (with-output-to-string (s) - (princ str s))))) + (t (princ-to-string str)))) + +(defun functionify (func) + "Convert the function-designator FUNC to a function." + (declare (type (or function symbol) func)) + (etypecase func + (function func) + (symbol (symbol-function func)))) + +(defun mappend (function list &rest more-lists) + "Apply FUNCTION to corresponding elements of LIST and MORE-LISTS, yielding + a list. Return the concatenation of all the resulting lists. Like + mapcan, but nondestructive." + (apply #'append (apply #'mapcar function list more-lists))) (compile-time-defun listify (x) "If X is a (possibly empty) list, return X; otherwise return (list X)." @@ -81,12 +112,12 @@ converted to their print representations." (compile-time-defun fix-pair (x &optional (y nil defaultp)) "Return two values extracted from X. It works as follows: - (A) -> A, Y - (A B) -> A, B - (A B . C) -> error - (A . B) -> A, B - A -> A, Y -where Y defaults to A if not specified." + (A) -> A, Y + (A B) -> A, B + (A B . C) -> error + (A . B) -> A, B + A -> A, Y + where Y defaults to A if not specified." (do-fix-pair x y defaultp)) (compile-time-defun pairify (x &optional (y nil defaultp)) @@ -96,15 +127,68 @@ where Y defaults to A if not specified." (defun whitespace-char-p (ch) "Return whether CH is a whitespace character or not." (case ch - ((#\space #\tab #\newline #\return #\vt #\formfeed) t) + (#.(loop for i below char-code-limit + for ch = (code-char i) + unless (with-input-from-string (in (string ch)) + (peek-char t in nil)) + collect ch) + t) (t nil))) +(defmacro defconstant* (name value &key doc test) + "Define a constant, like `defconstant'. The TEST is an equality test used + to decide whether to override the current definition, if any." + (let ((temp (gensym))) + `(eval-when (:compile-toplevel :load-toplevel :execute) + (let ((,temp ,value)) + (unless (and (boundp ',name) + (funcall ,(or test ''eql) (symbol-value ',name) ,temp)) + (defconstant ,name ,value ,@(and doc (list doc)))) + ',name)))) + (declaim (ftype (function nil ()) slot-unitialized)) (defun slot-uninitialized () "A function which signals an error. Can be used as an initializer form in -structure definitions without doom ensuing." + structure definitions without doom ensuing." (error "No initializer for slot.")) +(compile-time-defun parse-body (body &key (allow-docstring-p t)) + "Given a BODY (a list of forms), parses it into three sections: a + docstring, a list of declarations (forms beginning with the symbol + `declare') and the body forms. The result is returned as three lists + (even the docstring), suitable for interpolation into a backquoted list + using `@,'. If ALLOW-DOCSTRING-P is nil, docstrings aren't allowed at + all." + (let ((doc nil) (decls nil)) + (do ((forms body (cdr forms))) (nil) + (let ((form (and forms (car forms)))) + (cond ((and allow-docstring-p (not doc) (stringp form) (cdr forms)) + (setf doc form)) + ((and (consp form) + (eq (car form) 'declare)) + (setf decls (append decls (cdr form)))) + (t (return (values (and doc (list doc)) + (and decls (list (cons 'declare decls))) + forms)))))))) + +(defmacro with-parsed-body + ((bodyvar declvar &optional (docvar (gensym) docp)) form &body body) + "Parse FORM into a body, declarations and (maybe) a docstring; bind BODYVAR + to the body, DECLVAR to the declarations, and DOCVAR to (a list + containing) the docstring, and evaluate BODY." + `(multiple-value-bind + (,docvar ,declvar ,bodyvar) + (parse-body ,form :allow-docstring-p ,docp) + ,@(if docp nil `((declare (ignore ,docvar)))) + ,@body)) + +#-cmu +(progn + (declaim (inline fixnump)) + (defun fixnump (object) + "Answer non-nil if OBJECT is a fixnum, or nil if it isn't." + (typep object 'fixnum))) + ;;;-------------------------------------------------------------------------- ;;; Generating symbols. @@ -116,9 +200,9 @@ structure definitions without doom ensuing." (defmacro let*/gensyms (binds &body body) "A macro helper. BINDS is a list of binding pairs (VAR VALUE), where VALUE -defaults to VAR. The result is that BODY is evaluated in a context where -each VAR is bound to a gensym, and in the final expansion, each of those -gensyms will be bound to the corresponding VALUE." + defaults to VAR. The result is that BODY is evaluated in a context where + each VAR is bound to a gensym, and in the final expansion, each of those + gensyms will be bound to the corresponding VALUE." (labels ((more (binds) (let ((tmp (gensym "TMP")) (bind (car binds))) `((let ((,tmp ,(cadr bind)) @@ -148,9 +232,70 @@ gensyms will be bound to the corresponding VALUE." (defmacro while (cond &body body) "If COND is false, evaluate to nil; otherwise evaluate BODY and try again." - `(loop - (unless ,cond (return)) - ,@body)) + `(loop (unless ,cond (return)) (progn ,@body))) + +(defmacro until (cond &body body) + "If COND is true, evaluate to nil; otherwise evaluate BODY and try again." + `(loop (when ,cond (return)) (progn ,@body))) + +(compile-time-defun do-case2-like (kind vform clauses) + "Helper function for `case2' and `ecase2'." + (with-gensyms (scrutinee argument) + `(multiple-value-bind (,scrutinee ,argument) ,vform + (declare (ignorable ,argument)) + (,kind ,scrutinee + ,@(mapcar (lambda (clause) + (destructuring-bind + (cases (&optional varx vary) &rest forms) + clause + `(,cases + ,@(if varx + (list `(let ((,(or vary varx) ,argument) + ,@(and vary + `((,varx ,scrutinee)))) + ,@forms)) + forms)))) + clauses))))) + +(defmacro case2 (vform &body clauses) + "VFORM is a form which evaluates to two values, SCRUTINEE and ARGUMENT. + The CLAUSES have the form (CASES ([[SCRUVAR] ARGVAR]) FORMS...), where a + standard `case' clause has the form (CASES FORMS...). The `case2' form + evaluates the VFORM, and compares the SCRUTINEE to the various CASES, in + order, just like `case'. If there is a match, then the corresponding + FORMs are evaluated with ARGVAR bound to the ARGUMENT and SCRUVAR bound to + the SCRUTINEE (where specified). Note the bizarre defaulting behaviour: + ARGVAR is less optional than SCRUVAR." + (do-case2-like 'case vform clauses)) + +(defmacro ecase2 (vform &body clauses) + "Like `case2', but signals an error if no clause matches the SCRUTINEE." + (do-case2-like 'ecase vform clauses)) + +(defmacro setf-default (&rest specs &environment env) + "Like setf, but only sets places which are currently nil. + + The arguments are an alternating list of PLACEs and DEFAULTs. If a PLACE + is nil, the DEFAULT is evaluated and stored in the PLACE; otherwise the + default is /not/ stored. The result is the (new) value of the last + PLACE." + (labels ((doit (specs) + (cond ((null specs) nil) + ((null (cdr specs)) + (error "Odd number of arguments for SETF-DEFAULT.")) + (t + (let ((place (car specs)) + (default (cadr specs)) + (rest (cddr specs))) + (multiple-value-bind + (vars vals store-vals writer reader) + (get-setf-expansion place env) + `(let* ,(mapcar #'list vars vals) + (or ,reader + (multiple-value-bind ,store-vals ,default + ,writer)) + ,@(and rest (list (doit rest)))))))))) + (doit specs))) ;;;-------------------------------------------------------------------------- ;;; with-places @@ -166,10 +311,10 @@ gensyms will be bound to the corresponding VALUE." (defmacro with-places ((&key environment) places &body body) "A hairy helper, for writing setf-like macros. PLACES is a list of binding -pairs (VAR PLACE), where PLACE defaults to VAR. The result is that BODY is -evaluated in a context where each VAR is bound to a gensym, and in the final -expansion, each of those gensyms will be bound to a symbol-macro capable of -reading or setting the value of the corresponding PLACE." + pairs (VAR PLACE), where PLACE defaults to VAR. The result is that BODY + is evaluated in a context where each VAR is bound to a gensym, and in the + final expansion, each of those gensyms will be bound to a symbol-macro + capable of reading or setting the value of the corresponding PLACE." (if (null places) `(progn ,@body) (let*/gensyms (environment) @@ -231,10 +376,10 @@ reading or setting the value of the corresponding PLACE." (defmacro locf (place &environment env) "Slightly cheesy locatives. (locf PLACE) returns an object which, using -the `ref' function, can be used to read or set the value of PLACE. It's -cheesy because it uses closures rather than actually taking the address of -something. Also, unlike Zetalisp, we don't overload `car' to do our dirty -work." + the `ref' function, can be used to read or set the value of PLACE. It's + cheesy because it uses closures rather than actually taking the address of + something. Also, unlike Zetalisp, we don't overload `car' to do our dirty + work." (multiple-value-bind (valtmps valforms newtmps setform getform) (get-setf-expansion place env) @@ -254,13 +399,14 @@ work." (defmacro with-locatives (locs &body body) "LOCS is a list of items of the form (SYM [LOC-EXPR]), where SYM is a -symbol and LOC-EXPR evaluates to a locative. If LOC-EXPR is omitted, it -defaults to SYM. As an abbreviation for a common case, LOCS may be a symbol -instead of a list. The BODY is evaluated in an environment where each SYM is -a symbol macro which expands to (ref LOC-EXPR) -- or, in fact, something -similar which doesn't break if LOC-EXPR has side-effects. Thus, references, -including `setf' forms, fetch or modify the thing referred to by the -LOC-EXPR. Useful for covering over where something uses a locative." + symbol and LOC-EXPR evaluates to a locative. If LOC-EXPR is omitted, it + defaults to SYM. As an abbreviation for a common case, LOCS may be a + symbol instead of a list. The BODY is evaluated in an environment where + each SYM is a symbol macro which expands to (ref LOC-EXPR) -- or, in fact, + something similar which doesn't break if LOC-EXPR has side-effects. Thus, + references, including `setf' forms, fetch or modify the thing referred to + by the LOC-EXPR. Useful for covering over where something uses a + locative." (setf locs (mapcar #'pairify (listify locs))) (let ((tt (mapcar (lambda (l) (declare (ignore l)) (gensym)) locs)) (ll (mapcar #'cadr locs))