base: Export unsigned-fixnum as a handy type to have.

[lisp] / mdw-base.lisp

diff --git a/mdw-base.lisp b/mdw-base.lisp
index 4d67b7ae2498241a4299985090665254d99d1edb..c4c3e1748224af8bb00c0c73d3aa98363880ca71 100644 (file)
--- a/mdw-base.lisp
+++ b/mdw-base.lisp
@@ -28,43 +28,67 @@
 
 (defpackage #:mdw.base
   (:use #:common-lisp)
 
 (defpackage #:mdw.base
   (:use #:common-lisp)

-  (:export #:compile-time-defun
+  (:export #:unsigned-fixnum
+          #:compile-time-defun

           #:show
           #:show

-          #:stringify #:listify #:fix-pair #:pairify
+          #:stringify #:mappend #:listify #:fix-pair #:pairify #:parse-body

           #:whitespace-char-p
           #:slot-uninitialized
           #:whitespace-char-p
           #:slot-uninitialized

+          #:nlet #:while #:until #:case2 #:ecase2

           #:with-gensyms #:let*/gensyms #:with-places
           #:locp #:locf #:ref #:with-locatives
           #:update-place #:update-place-after
           #: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)
 
 (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
 ;;;--------------------------------------------------------------------------
 ;;; 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."
+   process."

   `(eval-when (:compile-toplevel :load-toplevel)
      (defun ,name ,args ,@body)))
 
 (defmacro show (x)
   `(eval-when (:compile-toplevel :load-toplevel)
      (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 (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~:[#<no values>~;~:*~{~S~^ ~_~}~]"
+                ',x
+                ,tmp))
+       (terpri)
+       (values-list ,tmp))))

 
 (defun stringify (str)
   "Return a string representation of STR.  Strings are returned unchanged;
 
 (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)))))
 
   (typecase str
     (string str)
     (symbol (symbol-name str))
     (t (with-output-to-string (s)
         (princ str s)))))
 

+(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)."
   (if (listp x) x (list x)))
 (compile-time-defun listify (x)
   "If X is a (possibly empty) list, return X; otherwise return (list X)."
   (if (listp x) x (list x)))


@@ -80,12 +104,12 @@ (compile-time-defun do-fix-pair (x y defaultp)
 
 (compile-time-defun fix-pair (x &optional (y nil defaultp))
   "Return two values extracted from X.  It works as follows:
 
 (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))
   (do-fix-pair x y defaultp))
 
 (compile-time-defun pairify (x &optional (y nil defaultp))


@@ -98,30 +122,38 @@ (defun whitespace-char-p (ch)
     ((#\space #\tab #\newline #\return #\vt #\formfeed) t)
     (t nil)))
 
     ((#\space #\tab #\newline #\return #\vt #\formfeed) t)
     (t nil)))
 

-(defmacro nlet (name binds &body body)
-  "Scheme's named let."
-  (multiple-value-bind (vars vals)
-      (loop for bind in binds
-           for (var val) = (pairify bind nil)
-           collect var into vars
-           collect val into vals
-           finally (return (values vars vals)))
-    `(labels ((,name ,vars
-               ,@body))
-       (,name ,@vals))))
-
-(defmacro while (cond &body body)
-  "If COND is false, evaluate to nil; otherwise evaluate BODY and try again."
-  `(loop
-     (unless `cond (return))
-     ,@body))
-

 (declaim (ftype (function nil ()) slot-unitialized))
 (defun slot-uninitialized ()
   "A function which signals an error.  Can be used as an initializer form in
 (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."))
 
   (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))))))))
+
+#-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.
 
 ;;;--------------------------------------------------------------------------
 ;;; Generating symbols.
 


@@ -133,9 +165,9 @@ (defmacro with-gensyms (syms &body body)
 
 (defmacro let*/gensyms (binds &body body)
   "A macro helper.  BINDS is a list of binding pairs (VAR VALUE), where VALUE
 
 (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))
   (labels ((more (binds)
              (let ((tmp (gensym "TMP")) (bind (car binds)))
                `((let ((,tmp ,(cadr bind))


@@ -148,6 +180,63 @@ (defmacro let*/gensyms (binds &body body)
         `(progn ,@body)
         (car (more (mapcar #'pairify (listify binds)))))))
 
         `(progn ,@body)
         (car (more (mapcar #'pairify (listify binds)))))))
 

+;;;--------------------------------------------------------------------------
+;;; Some simple yet useful control structures.
+
+(defmacro nlet (name binds &body body)
+  "Scheme's named let."
+  (multiple-value-bind (vars vals)
+      (loop for bind in binds
+           for (var val) = (pairify bind nil)
+           collect var into vars
+           collect val into vals
+           finally (return (values vars vals)))
+    `(labels ((,name ,vars
+               ,@body))
+       (,name ,@vals))))
+
+(defmacro while (cond &body body)
+  "If COND is false, evaluate to nil; otherwise evaluate BODY and try again."
+  `(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))
+

 ;;;--------------------------------------------------------------------------
 ;;; with-places
 
 ;;;--------------------------------------------------------------------------
 ;;; with-places
 


@@ -162,10 +251,10 @@ (define-setf-expander %place-ref (getform setform newtmp)
 
 (defmacro with-places ((&key environment) places &body body)
   "A hairy helper, for writing setf-like macros.  PLACES is a list of binding
 
 (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)
   (if (null places)
       `(progn ,@body)
       (let*/gensyms (environment)


@@ -227,10 +316,10 @@ (defstruct (loc (:predicate locp) (:constructor make-loc (reader writer)))
 
 (defmacro locf (place &environment env)
   "Slightly cheesy locatives.  (locf PLACE) returns an object which, using
 
 (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)
   (multiple-value-bind
       (valtmps valforms newtmps setform getform)
       (get-setf-expansion place env)


@@ -250,13 +339,14 @@ (defun (setf ref) (new loc)
 
 (defmacro with-locatives (locs &body body)
   "LOCS is a list of items of the form (SYM [LOC-EXPR]), where SYM is a
 
 (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))
   (setf locs (mapcar #'pairify (listify locs)))
   (let ((tt (mapcar (lambda (l) (declare (ignore l)) (gensym)) locs))
        (ll (mapcar #'cadr locs))