0.8.0.2:
[sbcl.git] / src / code / loop.lisp
index 59504a9..1f86e9f 100644 (file)
@@ -709,12 +709,10 @@ code to be loaded.
                        (setq n (+ n (estimate-code-size-1 (cadr l) env) 1))))
                     ((eq fn 'go) 1)
                     ((eq fn 'function)
-                     ;; This skirts the issue of implementationally-defined
-                     ;; lambda macros by recognizing CL function names and
-                     ;; nothing else.
-                     (if (or (symbolp (cadr x))
-                             (and (consp (cadr x)) (eq (caadr x) 'setf)))
+                     (if (sb!int:legal-fun-name-p (cadr x))
                          1
+                         ;; FIXME: This tag appears not to be present
+                         ;; anywhere.
                          (throw 'duplicatable-code-p nil)))
                     ((eq fn 'multiple-value-setq)
                      (f (length (second x)) (cddr x)))
@@ -760,9 +758,27 @@ code to be loaded.
                           specified-type required-type)))
        specified-type)))
 \f
+(defun subst-gensyms-for-nil (tree)
+  (declare (special *ignores*))
+  (cond
+    ((null tree) (car (push (gensym "LOOP-IGNORED-VAR-") *ignores*)))
+    ((atom tree) tree)
+    (t (cons (subst-gensyms-for-nil (car tree))
+            (subst-gensyms-for-nil (cdr tree))))))
+    
+(sb!int:defmacro-mundanely loop-destructuring-bind
+    (lambda-list arg-list &rest body)
+  (let ((*ignores* nil))
+    (declare (special *ignores*))
+    (let ((d-var-lambda-list (subst-gensyms-for-nil lambda-list)))
+      `(destructuring-bind ,d-var-lambda-list
+          ,arg-list
+        (declare (ignore ,@*ignores*))
+         ,@body))))
+
 (defun loop-build-destructuring-bindings (crocks forms)
   (if crocks
-      `((destructuring-bind ,(car crocks) ,(cadr crocks)
+      `((loop-destructuring-bind ,(car crocks) ,(cadr crocks)
         ,@(loop-build-destructuring-bindings (cddr crocks) forms)))
       forms))
 
@@ -883,17 +899,26 @@ code to be loaded.
   (setq *loop-emitted-body* t)
   (loop-pseudo-body form))
 
-(defun loop-emit-final-value (form)
-  (push (loop-construct-return form) *loop-after-epilogue*)
+(defun loop-emit-final-value (&optional (form nil form-supplied-p))
+  (when form-supplied-p
+    (push (loop-construct-return form) *loop-after-epilogue*))
   (when *loop-final-value-culprit*
-    (loop-warn "The LOOP clause is providing a value for the iteration,~@
-               however one was already established by a ~S clause."
+    (loop-warn "The LOOP clause is providing a value for the iteration;~@
+               however, one was already established by a ~S clause."
               *loop-final-value-culprit*))
   (setq *loop-final-value-culprit* (car *loop-source-context*)))
 
 (defun loop-disallow-conditional (&optional kwd)
   (when *loop-inside-conditional*
     (loop-error "~:[This LOOP~;The LOOP ~:*~S~] clause is not permitted inside a conditional." kwd)))
+
+(defun loop-disallow-anonymous-collectors ()
+  (when (find-if-not 'loop-collector-name *loop-collection-cruft*)
+    (loop-error "This LOOP clause is not permitted with anonymous collectors.")))
+
+(defun loop-disallow-aggregate-booleans ()
+  (when (loop-tmember *loop-final-value-culprit* '(always never thereis))
+    (loop-error "This anonymous collection LOOP clause is not permitted with aggregate booleans.")))
 \f
 ;;;; loop types
 
@@ -986,6 +1011,13 @@ code to be loaded.
          *loop-desetq-crocks* nil
          *loop-wrappers* nil)))
 
+(defun loop-var-p (name)
+  (do ((entry *loop-bind-stack* (cdr entry)))
+      (nil)
+    (cond
+      ((null entry) (return nil))
+      ((assoc name (caar entry) :test #'eq) (return t)))))
+
 (defun loop-make-var (name initialization dtype &optional iteration-var-p)
   (cond ((null name)
         (cond ((not (null initialization))
@@ -1048,7 +1080,10 @@ code to be loaded.
       (loop-make-var (gensym "LOOP-BIND-") form data-type)))
 \f
 (defun loop-do-if (for negatep)
-  (let ((form (loop-get-form)) (*loop-inside-conditional* t) (it-p nil))
+  (let ((form (loop-get-form))
+       (*loop-inside-conditional* t)
+       (it-p nil)
+       (first-clause-p t))
     (flet ((get-clause (for)
             (do ((body nil)) (nil)
               (let ((key (car *loop-source-code*)) (*loop-body* nil) data)
@@ -1058,7 +1093,8 @@ code to be loaded.
                          key for))
                       (t (setq *loop-source-context* *loop-source-code*)
                          (loop-pop-source)
-                         (when (loop-tequal (car *loop-source-code*) 'it)
+                         (when (and (loop-tequal (car *loop-source-code*) 'it)
+                                    first-clause-p)
                            (setq *loop-source-code*
                                  (cons (or it-p
                                            (setq it-p
@@ -1073,6 +1109,7 @@ code to be loaded.
                                   "~S does not introduce a LOOP clause that can follow ~S."
                                   key for))
                                (t (setq body (nreconc *loop-body* body)))))))
+              (setq first-clause-p nil)
               (if (loop-tequal (car *loop-source-code*) :and)
                   (loop-pop-source)
                   (return (if (cdr body)
@@ -1110,7 +1147,7 @@ code to be loaded.
     (when *loop-names*
       (loop-error "You may only use one NAMED clause in your loop: NAMED ~S ... NAMED ~S."
                  (car *loop-names*) name))
-    (setq *loop-names* (list name nil))))
+    (setq *loop-names* (list name))))
 
 (defun loop-do-return ()
   (loop-pseudo-body (loop-construct-return (loop-get-form))))
@@ -1135,11 +1172,15 @@ code to be loaded.
                (loop-pop-source))))
     (when (not (symbolp name))
       (loop-error "The value accumulation recipient name, ~S, is not a symbol." name))
+    (unless name
+      (loop-disallow-aggregate-booleans))
     (unless dtype
       (setq dtype (or (loop-optional-type) default-type)))
     (let ((cruft (find (the symbol name) *loop-collection-cruft*
                       :key #'loop-collector-name)))
       (cond ((not cruft)
+            (when (and name (loop-var-p name))
+              (loop-error "Variable ~S in INTO clause is a duplicate" name))
             (push (setq cruft (make-loop-collector
                                 :name name :class class
                                 :history (list collector) :dtype dtype))
@@ -1231,6 +1272,7 @@ code to be loaded.
 (defun loop-do-always (restrictive negate)
   (let ((form (loop-get-form)))
     (when restrictive (loop-disallow-conditional))
+    (loop-disallow-anonymous-collectors)
     (loop-emit-body `(,(if negate 'when 'unless) ,form
                      ,(loop-construct-return nil)))
     (loop-emit-final-value t)))
@@ -1240,13 +1282,31 @@ code to be loaded.
 ;;; Under ANSI this is not permitted to appear under conditionalization.
 (defun loop-do-thereis (restrictive)
   (when restrictive (loop-disallow-conditional))
+  (loop-disallow-anonymous-collectors)
+  (loop-emit-final-value)
   (loop-emit-body `(when (setq ,(loop-when-it-var) ,(loop-get-form))
-                    ,(loop-construct-return *loop-when-it-var*))))
+                   ,(loop-construct-return *loop-when-it-var*))))
 \f
 (defun loop-do-while (negate kwd &aux (form (loop-get-form)))
   (loop-disallow-conditional kwd)
   (loop-pseudo-body `(,(if negate 'when 'unless) ,form (go end-loop))))
 
+(defun loop-do-repeat ()
+  (loop-disallow-conditional :repeat)
+  (let ((form (loop-get-form))
+       (type 'integer))
+    (let ((var (loop-make-var (gensym "LOOP-REPEAT-") `(ceiling ,form) type)))
+      (push `(if (<= ,var 0) (go end-loop) (decf ,var)) *loop-before-loop*)
+      (push `(if (<= ,var 0) (go end-loop) (decf ,var)) *loop-after-body*)
+      ;; FIXME: What should
+      ;;   (loop count t into a
+      ;;         repeat 3
+      ;;         count t into b
+      ;;         finally (return (list a b)))
+      ;; return: (3 3) or (4 3)? PUSHes above are for the former
+      ;; variant, L-P-B below for the latter.
+      #+nil (loop-pseudo-body `(when (minusp (decf ,var)) (go end-loop))))))
+
 (defun loop-do-with ()
   (loop-disallow-conditional :with)
   (do ((var) (val) (dtype)) (nil)
@@ -1256,6 +1316,8 @@ code to be loaded.
                     (loop-pop-source)
                     (loop-get-form))
                    (t nil)))
+    (when (and var (loop-var-p var))
+      (loop-error "Variable ~S has already been used" var))
     (loop-make-var var val dtype)
     (if (loop-tequal (car *loop-source-code*) :and)
        (loop-pop-source)
@@ -1348,24 +1410,6 @@ code to be loaded.
                  keyword))
     (apply (car tem) var first-arg data-type (cdr tem))))
 
-(defun loop-do-repeat ()
-  (let ((form (loop-get-form))
-       (type (loop-check-data-type (loop-optional-type)
-                                   'real)))
-    (when (and (consp form)
-              (eq (car form) 'the)
-              (sb!xc:subtypep (second form) type))
-      (setq type (second form)))
-    (multiple-value-bind (number constantp value)
-       (loop-constant-fold-if-possible form type)
-      (cond ((and constantp (<= value 1)) `(t () () () ,(<= value 0) () () ()))
-           (t (let ((var (loop-make-var (gensym "LOOP-REPEAT-") number type)))
-                (if constantp
-                    `((not (plusp (setq ,var (1- ,var))))
-                      () () () () () () ())
-                    `((minusp (setq ,var (1- ,var)))
-                      () () ()))))))))
-
 (defun loop-when-it-var ()
   (or *loop-when-it-var*
       (setq *loop-when-it-var*
@@ -1806,22 +1850,22 @@ code to be loaded.
          (:hash-value (setq key-var (and other-p other-var)
                             val-var variable)))
        (push `(with-hash-table-iterator (,next-fn ,ht-var)) *loop-wrappers*)
-       (when (consp key-var)
-         (setq post-steps
-               `(,key-var ,(setq key-var (gensym "LOOP-HASH-KEY-TEMP-"))
-                          ,@post-steps))
-         (push `(,key-var nil) bindings))
-       (when (consp val-var)
-         (setq post-steps
-               `(,val-var ,(setq val-var (gensym "LOOP-HASH-VAL-TEMP-"))
-                          ,@post-steps))
-         (push `(,val-var nil) bindings))
-       `(,bindings                             ;bindings
-         ()                                    ;prologue
-         ()                                    ;pre-test
-         ()                                    ;parallel steps
+        (when (or (consp key-var) data-type)
+          (setq post-steps
+                `(,key-var ,(setq key-var (gensym "LOOP-HASH-KEY-TEMP-"))
+                           ,@post-steps))
+          (push `(,key-var nil) bindings))
+        (when (or (consp val-var) data-type)
+          (setq post-steps
+                `(,val-var ,(setq val-var (gensym "LOOP-HASH-VAL-TEMP-"))
+                           ,@post-steps))
+          (push `(,val-var nil) bindings))
+       `(,bindings                     ;bindings
+         ()                            ;prologue
+         ()                            ;pre-test
+         ()                            ;parallel steps
          (not (multiple-value-setq (,dummy-predicate-var ,key-var ,val-var)
-                (,next-fn)))   ;post-test
+                (,next-fn)))           ;post-test
          ,post-steps)))))
 
 (defun loop-package-symbols-iteration-path (variable data-type prep-phrases
@@ -1883,7 +1927,8 @@ code to be loaded.
                         (when (loop-do-if when nil))   ; Normal, do when
                         (if (loop-do-if if nil))       ; synonymous
                         (unless (loop-do-if unless t)) ; Negate test on when
-                        (with (loop-do-with)))
+                        (with (loop-do-with))
+                         (repeat (loop-do-repeat)))
             :for-keywords '((= (loop-ansi-for-equals))
                             (across (loop-for-across))
                             (in (loop-for-in))
@@ -1899,8 +1944,7 @@ code to be loaded.
                             (by (loop-for-arithmetic :by))
                             (being (loop-for-being)))
             :iteration-keywords '((for (loop-do-for))
-                                  (as (loop-do-for))
-                                  (repeat (loop-do-repeat)))
+                                  (as (loop-do-for)))
             :type-symbols '(array atom bignum bit bit-vector character
                             compiled-function complex cons double-float
                             fixnum float function hash-table integer
@@ -1944,9 +1988,9 @@ code to be loaded.
 
 (defun loop-standard-expansion (keywords-and-forms environment universe)
   (if (and keywords-and-forms (symbolp (car keywords-and-forms)))
-    (loop-translate keywords-and-forms environment universe)
-    (let ((tag (gensym)))
-      `(block nil (tagbody ,tag (progn ,@keywords-and-forms) (go ,tag))))))
+      (loop-translate keywords-and-forms environment universe)
+      (let ((tag (gensym)))
+       `(block nil (tagbody ,tag (progn ,@keywords-and-forms) (go ,tag))))))
 
 (sb!int:defmacro-mundanely loop (&environment env &rest keywords-and-forms)
   (loop-standard-expansion keywords-and-forms env *loop-ansi-universe*))