Commit d3eb84b8 authored by wlott's avatar wlott
Browse files

Fixed spelling of descend (was decend). Added magic to output-structure

to notice if the user structure printer also tried to do depth abbrevs
and circularity detection, and blow it off 'cause we've already done it.
parent 40123dee
......@@ -7,7 +7,7 @@
;;; Scott Fahlman or
"$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/print.lisp,v 1.29 1991/12/05 05:12:22 wlott Exp $")
"$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/print.lisp,v 1.30 1991/12/13 06:04:37 wlott Exp $")
;;; **********************************************************************
......@@ -30,7 +30,7 @@
(in-package "KERNEL")
(export '(*current-level* *pretty-printer* output-object output-ugly-object
check-for-circularity handle-circularity with-circularity-detection
decend-into punt-if-too-long))
descend-into punt-if-too-long))
(in-package "LISP")
......@@ -248,7 +248,8 @@
(error "~S cannot be printed readably." object))
(write-string "#<" stream)
(when type
(write (type-of object) :stream stream :circle nil :level nil :length nil)
(write (type-of object) :stream stream :circle nil
:level nil :length nil)
(when (or body identity)
(write-char #\space stream)))
(when body
......@@ -257,7 +258,8 @@
(when body
(write-char #\space stream))
(write-char #\{ stream)
(write (get-lisp-obj-address object) :stream stream :radix nil :base 16)
(write (get-lisp-obj-address object) :stream stream
:radix nil :base 16)
(write-char #\} stream))
(write-char #\> stream))
......@@ -273,11 +275,43 @@
(char= char #\return)
(char= char #\linefeed)))
;;;; Circularity detection stuff.
;;; *CURRENT-STRUCTURE* -- internal
;;; We have to bend over backwards in order to make sure depth abbrevs and
;;; circularity detection work right despite the fact that the user supplied
;;; print function may or may not do anything special.
;;; In order to correctly handle depth abbrevs, OUTPUT-STRUCTURE binds a
;;; this to the structure being output. If the descend-into stuff notices
;;; that we are trying to descend into that structure, we don't bother
;;; doing the depth check/inc because we know it's already been done. But
;;; if we try to descend into something else, then we know that the
;;; structure printer is being stupid and didn't check the depth or for
;;; circularities.
(defvar *current-structure* nil)
;;; *CIRCULARITY-HASH-TABLE* -- internal.
;;; When *print-circle* is T, this gets bound to a hash table that (eventually)
;;; ends up with entries for every object printed. When we are initially
;;; looking for circularities, we enter a T when we find an object for the
;;; first time, and a 0 when we encounter an object a second time around.
;;; When we are actually printing, the 0 entries get changed to the actual
;;; marker value when they are first printed.
(defvar *circularity-hash-table* nil)
;;; *CIRCULARITY-COUNTER* -- internal.
;;; When NIL, we are just looking for circularities. After we have found them
;;; all, this gets bound to 0. Then whenever we need a new marker, it is
;;; incremented.
(defvar *circularity-counter* nil)
;;; CHECK-FOR-CIRCULARITY -- interface.
......@@ -296,6 +330,9 @@
(cond ((null *print-circle*)
;; Don't bother, nobody cares.
((eq object *current-structure*)
;; It's already been handled by output-structure.
((null *circularity-hash-table*)
((null *circularity-counter*)
......@@ -376,7 +413,8 @@
(checker (gensym)))
(once-only ((object object))
`(labels ((,user-body (,stream)
(let ((*current-structure* nil))
(,checker (,stream)
(let ((marker (check-for-circularity ,object t)))
(case marker
......@@ -400,26 +438,38 @@
(defvar *current-level* 0
"The current level we are printing at, to be compared against *PRINT-LEVEL*.
See the macro DECEND-INTO for a handy interface to depth abbreviation.")
See the macro DESCEND-INTO for a handy interface to depth abbreviation.")
;;; DECEND-INTO -- interface.
;;; DESCEND-INTO -- interface.
(defmacro decend-into ((object stream) &body body)
(defmacro descend-into ((object stream) &body body)
"Automatically handle *print-level* abbreviation and circularity detection.
If we are too deep, then a # is printed to STREAM and BODY is ignored.
If OBJECT isn't NIL, then it is checked to see if it is a circular
reference (see WITH-CIRCULARITY-DETECTION), and handled accordingly.
BODY should do it's output to STREAM (which might be rebound)."
(let ((guts `(let ((*current-level* (1+ *current-level*)))
`(if (and (null *print-readably*)
(>= *current-level* *print-level*))
(write-char #\# ,stream)
,(if object
`(with-circularity-detection (,object ,stream)
(if object
(once-only ((object object))
`(if (and (null *print-readably*)
(>= *current-level* *print-level*)
(or (null *current-structure*)
(not (eq *current-structure* ,object))))
(write-char #\# ,stream)
(with-circularity-detection (,object ,stream)
(let ((*current-level*
(if (or (null *current-structure*)
(not (eq *current-structure* ,object)))
(1+ *current-level*)
`(if (and (null *print-readably*)
(>= *current-level* *print-level*))
(write-char #\# ,stream)
(let ((*current-structure* nil)
(*current-level* (1+ *current-level*)))
;;; PUNT-IF-TOO-LONG -- interface.
......@@ -872,7 +922,7 @@
;;;; Recursive objects.
(defun output-list (list stream)
(decend-into (list stream)
(descend-into (list stream)
(write-char #\( stream)
(let ((length 0)
(list list))
......@@ -906,7 +956,7 @@
(when (and *print-readably*
(not (eq (array-element-type vector) 't)))
(error "Cannot print ~S in a readable format." vector))
(decend-into (vector stream)
(descend-into (vector stream)
(write-string "#(" stream)
(dotimes (i (length vector))
(unless (zerop i)
......@@ -950,7 +1000,7 @@
(not (eq (array-element-type array) t)))
(error "Arrays of element-type ~S cannot be printed readably."
(array-element-type array)))
(decend-into (array stream)
(descend-into (array stream)
(write-char #\# stream)
(let ((*print-base* 10))
(output-integer (array-rank array) stream))
......@@ -964,7 +1014,7 @@
(cond ((null dimensions)
(output-object (svref array index) stream))
(decend-into (nil stream)
(descend-into (nil stream)
(write-char #\( stream)
(let* ((dimension (car dimensions))
(dimensions (cdr dimensions))
......@@ -989,10 +1039,12 @@
;;; Defstruct code.
(defun output-structure (structure stream)
(decend-into (structure stream)
(funcall (or (info type printer (structure-ref structure 0))
structure stream *current-level*)))
(let ((*current-structure* nil))
(descend-into (stream structure)
(let ((*current-structure* structure))
(funcall (or (info type printer (structure-ref structure 0))
structure stream *current-level*)))))
;;;; Integer, ratio, and complex printing. (i.e. everything but floats)
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