;;; The flags passed back by BACKQUOTIFY can be interpreted as follows:
;;;
;;; |`,|: [a] => a
-;;; NIL: [a] => a ;the NIL flag is used only when a is NIL
-;;; T: [a] => a ;the T flag is used when a is self-evaluating
+;;; NIL: [a] => a ;the NIL flag is used only when a is NIL
+;;; T: [a] => a ;the T flag is used when a is self-evaluating
;;; QUOTE: [a] => (QUOTE a)
;;; APPEND: [a] => (APPEND . a)
;;; NCONC: [a] => (NCONC . a)
(defvar *bq-at-flag* '(|,@|))
(defvar *bq-dot-flag* '(|,.|))
(defvar *bq-vector-flag* '(|bqv|))
+(defvar *bq-error* "Comma not inside a backquote.")
(/show0 "backq.lisp 50")
(declare (ignore ignore))
(let ((*backquote-count* (1+ *backquote-count*)))
(multiple-value-bind (flag thing)
- (backquotify stream (read stream t nil t))
+ (backquotify stream (read stream t nil t))
(when (eq flag *bq-at-flag*)
- (%reader-error stream ",@ after backquote in ~S" thing))
+ (simple-reader-error stream ",@ after backquote in ~S" thing))
(when (eq flag *bq-dot-flag*)
- (%reader-error stream ",. after backquote in ~S" thing))
+ (simple-reader-error stream ",. after backquote in ~S" thing))
(backquotify-1 flag thing))))
(/show0 "backq.lisp 64")
(unless (> *backquote-count* 0)
(when *read-suppress*
(return-from comma-macro nil))
- (%reader-error stream "comma not inside a backquote"))
+ (simple-reader-error stream *bq-error*))
(let ((c (read-char stream))
- (*backquote-count* (1- *backquote-count*)))
- (cond ((char= c #\@)
- (cons *bq-at-flag* (read stream t nil t)))
- ((char= c #\.)
- (cons *bq-dot-flag* (read stream t nil t)))
- (t (unread-char c stream)
- (cons *bq-comma-flag* (read stream t nil t))))))
+ (*backquote-count* (1- *backquote-count*)))
+ (flet ((check (what)
+ (let ((x (peek-char t stream t nil t)))
+ (when (and (char= x #\)) (eq #'read-right-paren (get-macro-character #\))))
+ ;; Easier to figure out than an "unmatched parenthesis".
+ (simple-reader-error stream "Trailing ~A in backquoted expression." what)))))
+ (cond ((char= c #\@)
+ (check "comma-at")
+ (cons *bq-at-flag* (read stream t nil t)))
+ ((char= c #\.)
+ (check "comma-dot")
+ (cons *bq-dot-flag* (read stream t nil t)))
+ (t
+ (unread-char c stream)
+ (check "comma")
+ (cons *bq-comma-flag* (read stream t nil t)))))))
(/show0 "backq.lisp 83")
(or (eq flag *bq-at-flag*)
(eq flag *bq-dot-flag*)))))
+(defun backquote-splice (method dflag a d what stream)
+ (cond (dflag
+ (values method
+ (cond ((eq dflag method)
+ (cons a d))
+ (t (list a (backquotify-1 dflag d))))))
+ ((expandable-backq-expression-p a)
+ (values method (list a)))
+ ((not (and (atom a) (backq-constant-p a)))
+ ;; COMMA special cases a few constant atoms, which
+ ;; are illegal in splices.
+ (comma a))
+ (t
+ (simple-reader-error stream "Invalid splice in backquote: ~A~A" what a))))
+
;;; This does the expansion from table 2.
(defun backquotify (stream code)
(cond ((atom code)
- (cond ((null code) (values nil nil))
- ((or (consp code)
+ (cond ((null code) (values nil nil))
+ ((or (consp code)
(symbolp code))
- ;; Keywords are self-evaluating. Install after packages.
+ ;; Keywords are self-evaluating. Install after packages.
(values 'quote code))
- (t (values t code))))
- ((or (eq (car code) *bq-at-flag*)
- (eq (car code) *bq-dot-flag*))
- (values (car code) (cdr code)))
- ((eq (car code) *bq-comma-flag*)
- (comma (cdr code)))
- ((eq (car code) *bq-vector-flag*)
- (multiple-value-bind (dflag d) (backquotify stream (cdr code))
- (values 'vector (backquotify-1 dflag d))))
- (t (multiple-value-bind (aflag a) (backquotify stream (car code))
- (multiple-value-bind (dflag d) (backquotify stream (cdr code))
- (when (eq dflag *bq-at-flag*)
- ;; Get the errors later.
- (%reader-error stream ",@ after dot in ~S" code))
- (when (eq dflag *bq-dot-flag*)
- (%reader-error stream ",. after dot in ~S" code))
- (cond
- ((eq aflag *bq-at-flag*)
- (if (null dflag)
- (if (expandable-backq-expression-p a)
- (values 'append (list a))
- (comma a))
- (values 'append
- (cond ((eq dflag 'append)
- (cons a d ))
- (t (list a (backquotify-1 dflag d)))))))
- ((eq aflag *bq-dot-flag*)
- (if (null dflag)
- (if (expandable-backq-expression-p a)
- (values 'nconc (list a))
- (comma a))
- (values 'nconc
- (cond ((eq dflag 'nconc)
- (cons a d))
- (t (list a (backquotify-1 dflag d)))))))
- ((null dflag)
- (if (member aflag '(quote t nil))
- (values 'quote (list a))
- (values 'list (list (backquotify-1 aflag a)))))
- ((member dflag '(quote t))
- (if (member aflag '(quote t nil))
- (values 'quote (cons a d ))
- (values 'list* (list (backquotify-1 aflag a)
- (backquotify-1 dflag d)))))
- (t (setq a (backquotify-1 aflag a))
- (if (member dflag '(list list*))
- (values dflag (cons a d))
- (values 'list*
- (list a (backquotify-1 dflag d)))))))))))
+ (t (values t code))))
+ ((or (eq (car code) *bq-at-flag*)
+ (eq (car code) *bq-dot-flag*))
+ (values (car code) (cdr code)))
+ ((eq (car code) *bq-comma-flag*)
+ (comma (cdr code)))
+ ((eq (car code) *bq-vector-flag*)
+ (multiple-value-bind (dflag d) (backquotify stream (cdr code))
+ (values 'vector (backquotify-1 dflag d))))
+ (t (multiple-value-bind (aflag a) (backquotify stream (car code))
+ (multiple-value-bind (dflag d) (backquotify stream (cdr code))
+ (when (eq dflag *bq-at-flag*)
+ ;; Get the errors later.
+ (simple-reader-error stream ",@ after dot in ~S" code))
+ (when (eq dflag *bq-dot-flag*)
+ (simple-reader-error stream ",. after dot in ~S" code))
+ (cond
+ ((eq aflag *bq-at-flag*)
+ (backquote-splice 'append dflag a d ",@" stream))
+ ((eq aflag *bq-dot-flag*)
+ (backquote-splice 'nconc dflag a d ",." stream))
+ ((null dflag)
+ (if (member aflag '(quote t nil))
+ (values 'quote (list a))
+ (values 'list (list (backquotify-1 aflag a)))))
+ ((member dflag '(quote t))
+ (if (member aflag '(quote t nil))
+ (values 'quote (cons a d ))
+ (values 'list* (list (backquotify-1 aflag a)
+ (backquotify-1 dflag d)))))
+ (t (setq a (backquotify-1 aflag a))
+ (if (member dflag '(list list*))
+ (values dflag (cons a d))
+ (values 'list*
+ (list a (backquotify-1 dflag d)))))))))))
(/show0 "backq.lisp 139")
+(defun backq-constant-p (x)
+ (or (numberp x) (eq x t)))
+
;;; This handles the <hair> cases.
(defun comma (code)
(cond ((atom code)
- (cond ((null code)
- (values nil nil))
- ((or (numberp code) (eq code t))
- (values t code))
- (t (values *bq-comma-flag* code))))
- ((and (eq (car code) 'quote)
+ (cond ((null code)
+ (values nil nil))
+ ((backq-constant-p code)
+ (values t code))
+ (t
+ (values *bq-comma-flag* code))))
+ ((and (eq (car code) 'quote)
(not (expandable-backq-expression-p (cadr code))))
(values (car code) (cadr code)))
- ((member (car code) '(append list list* nconc))
- (values (car code) (cdr code)))
- ((eq (car code) 'cons)
- (values 'list* (cdr code)))
- (t (values *bq-comma-flag* code))))
+ ((member (car code) '(append list list* nconc))
+ (values (car code) (cdr code)))
+ ((eq (car code) 'cons)
+ (values 'list* (cdr code)))
+ (t (values *bq-comma-flag* code))))
(/show0 "backq.lisp 157")
;;; This handles table 1.
(defun backquotify-1 (flag thing)
(cond ((or (eq flag *bq-comma-flag*)
- (member flag '(t nil)))
- thing)
- ((eq flag 'quote)
- (list 'quote thing))
- ((eq flag 'list*)
+ (member flag '(t nil)))
+ thing)
+ ((eq flag 'quote)
+ (list 'quote thing))
+ ((eq flag 'list*)
(cond ((and (null (cddr thing))
+ (not (expandable-backq-expression-p (car thing)))
(not (expandable-backq-expression-p (cadr thing))))
- (cons 'backq-cons thing))
- ((expandable-backq-expression-p (car (last thing)))
+ (cons 'backq-cons thing))
+ ((expandable-backq-expression-p (car (last thing)))
(list 'backq-append
(cons 'backq-list (butlast thing))
;; Can it be optimized further? -- APD, 2001-12-21
(car (last thing))))
(t
- (cons 'backq-list* thing))))
- ((eq flag 'vector)
- (list 'backq-vector thing))
- (t (cons (cdr
- (assoc flag
- '((cons . backq-cons)
- (list . backq-list)
- (append . backq-append)
- (nconc . backq-nconc))
- :test #'equal))
- thing))))
+ (cons 'backq-list* thing))))
+ ((eq flag 'vector)
+ (list 'backq-vector thing))
+ (t (cons (ecase flag
+ ((list) 'backq-list)
+ ((append) 'backq-append)
+ ((nconc) 'backq-nconc))
+ thing))))
\f
;;;; magic BACKQ- versions of builtin functions
;;; them, the backquoted material will be recognizable to the
;;; pretty-printer.
(macrolet ((def (b-name name)
- (let ((args (gensym "ARGS")))
- ;; FIXME: This function should be INLINE so that the lists
- ;; aren't consed twice, but I ran into an optimizer bug the
- ;; first time I tried to make this work for BACKQ-LIST. See
- ;; whether there's still an optimizer bug, and fix it if so, and
- ;; then make these INLINE.
- `(defun ,b-name (&rest ,args)
- (apply #',name ,args)))))
+ ;; FIXME: This function should be INLINE so that the lists
+ ;; aren't consed twice, but I ran into an optimizer bug the
+ ;; first time I tried to make this work for BACKQ-LIST. See
+ ;; whether there's still an optimizer bug, and fix it if so, and
+ ;; then make these INLINE.
+ `(defun ,b-name (&rest rest)
+ (declare (truly-dynamic-extent rest))
+ (apply #',name rest))))
(def backq-list list)
(def backq-list* list*)
(def backq-append append)
;;; Since our backquote is installed on the host lisp, and since
;;; developers make mistakes with backquotes and commas too, let's
;;; ensure that we can report errors rather than get an undefined
-;;; function condition on %READER-ERROR.
+;;; function condition on SIMPLE-READER-ERROR.
#+sb-xc-host ; proper definition happens for the target
-(defun %reader-error (stream format-string &rest format-args)
+(defun simple-reader-error (stream format-string &rest format-args)
(bug "READER-ERROR on stream ~S: ~?" stream format-string format-args))
(/show0 "done with backq.lisp")
projects / sbcl.git / blobdiff