(cl:defpackage :sb-aclrepl   (:use "COMMON-LISP" "SB-EXT")   (:shadowing-import-from "SB-IMPL" "SCRUB-CONTROL-STACK")   (:shadowing-import-from "SB-INT" "*REPL-PROMPT-FUN*" "*REPL-READ-FORM-FUN*" "*STEP*" "*STEPPING*")   (:export    ;; user-level customization of UI   "*PROMPT*" "*EXIT-ON-EOF*" "*MAX-HISTORY*"    "*USE-SHORT-PACKAGE-NAME*" "*COMMAND-CHAR*"    ;; user-level customization of functionality   "ALIAS"    ;; internalsish, but the documented way to make a new repl "object"   ;; such that it inherits the current state of the repl but has its   ;; own independent state subsequently.   "MAKE-REPL-FUN")) (cl:in-package :sb-aclrepl) (defvar *noprint* nil   "boolean: T if don't print prompt and output") (defvar *break-level* 0   "current break level") (defvar *inspect-break* nil   "boolean: T if break caused by inspect") (defvar *continuable-break* nil   "boolean: T if break caused by continuable error") (defun repl (&key              (break-level (1+ *break-level*))              (noprint *noprint*)              (inspect nil)              (continuable nil))   (let ((*noprint* noprint)         (*break-level* break-level)         (*inspect-break* inspect)         (*continuable-break* continuable))     (sb-int:/show0 "entering REPL")     (loop      (multiple-value-bind (reason reason-param)          (catch 'repl-catcher            (loop             (unwind-protect                  (rep-one)               ;; reset toplevel step-condition handler              (setf *step* nil                     *stepping* nil))))        (declare (ignore reason-param))        (cond          ((and (eq reason :inspect)                (plusp *break-level*))           (return-from repl))          ((and (eq reason :pop)                (plusp *break-level*))           (return-from repl))))))) (defun rep-one ()   "Read-Eval-Print one form"   ;; (See comment preceding the definition of SCRUB-CONTROL-STACK.)  (scrub-control-stack)   (unless *noprint*     (funcall *repl-prompt-fun* *standard-output*)     ;; (Should *REPL-PROMPT-FUN* be responsible for doing its own    ;; FORCE-OUTPUT? I can't imagine a valid reason for it not to    ;; be done here, so leaving it up to *REPL-PROMPT-FUN* seems    ;; odd. But maybe there *is* a valid reason in some    ;; circumstances? perhaps some deadlock issue when being driven    ;; by another process or something...)    (force-output *standard-output*))   (let* ((form (funcall *repl-read-form-fun*                         *standard-input*                         *standard-output*))          (results (multiple-value-list (sb-impl::interactive-eval form))))     (unless *noprint*       (dolist (result results)         ;; FIXME: Calling fresh-line before a result ensures the result starts        ;; on a newline, but it usually generates an empty line.        ;; One solution would be to have the newline's entered on the        ;; input stream inform the output stream that the column should be        ;; reset to the beginning of the line.        (fresh-line *standard-output*)         (prin1 result *standard-output*)))))