(in-package "SB!KERNEL")
\f
-;;;; miscellaneous support utilities
-
-;;; Signalling an error when trying to print an error condition is
-;;; generally a PITA, so whatever the failure encountered when
-;;; wondering about FILE-POSITION within a condition printer, 'tis
-;;; better silently to give up than to try to complain.
-(defun file-position-or-nil-for-error (stream &optional (pos nil posp))
- ;; Arguably FILE-POSITION shouldn't be signalling errors at all; but
- ;; "NIL if this cannot be determined" in the ANSI spec doesn't seem
- ;; absolutely unambiguously to prohibit errors when, e.g., STREAM
- ;; has been closed so that FILE-POSITION is a nonsense question. So
- ;; my (WHN) impression is that the conservative approach is to
- ;; IGNORE-ERRORS. (I encountered this failure from within a homebrew
- ;; defsystemish operation where the ERROR-STREAM had been CL:CLOSEd,
- ;; I think by nonlocally exiting through a WITH-OPEN-FILE, by the
- ;; time an error was reported.)
- (if posp
- (ignore-errors (file-position stream pos))
- (ignore-errors (file-position stream))))
-\f
;;;; the CONDITION class
(/show0 "condition.lisp 20")
(:report (lambda (condition stream)
(%report-reader-error condition stream :simple t))))
-(defun stream-error-position-info (stream &optional position)
- (unless (interactive-stream-p stream)
- (let ((now (file-position-or-nil-for-error stream))
- (pos position))
- (when (and (not pos) now (plusp now))
- ;; FILE-POSITION is the next character -- error is at the previous one.
- (setf pos (1- now)))
- (let (lineno colno)
- (when (and pos
- (< pos sb!xc:array-dimension-limit)
- (file-position stream :start))
- (let ((string
- (make-string pos :element-type (stream-element-type stream))))
- (when (= pos (read-sequence string stream))
- ;; Lines count from 1, columns from 0. It's stupid and traditional.
- (setq lineno (1+ (count #\Newline string))
- colno (- pos (or (position #\Newline string :from-end t) 0)))))
- (file-position-or-nil-for-error stream now))
- (remove-if-not #'second
- (list (list :line lineno)
- (list :column colno)
- (list :file-position pos)))))))
-
;;; base REPORTing of a READER-ERROR
;;;
;;; When SIMPLE, we expect and use SIMPLE-CONDITION-ish FORMAT-CONTROL