(require 'comint)
(require 'lisp-mode)

;;;###autoload
(defvar inferior-lisp-filter-regexp "\\`\\s *\\(:\\(\\w\\|\\s_\\)\\)?\\s *\\'"
  "*What not to save on inferior Lisp's input history.
Input matching this regexp is not saved on the input history in Inferior Lisp
mode.  Default is whitespace followed by 0 or 1 single-letter colon-keyword
\(as in :a, :c, etc.)")

(defvar inferior-lisp-mode-map nil)
(unless inferior-lisp-mode-map
  (setq inferior-lisp-mode-map (copy-keymap comint-mode-map))
  (set-keymap-parent inferior-lisp-mode-map lisp-mode-shared-map)
  (define-key inferior-lisp-mode-map "\C-x\C-e" 'lisp-eval-last-sexp)
  (define-key inferior-lisp-mode-map "\C-c\C-l" 'lisp-load-file)
  (define-key inferior-lisp-mode-map "\C-c\C-k" 'lisp-compile-file)
  (define-key inferior-lisp-mode-map "\C-c\C-a" 'lisp-show-arglist)
  (define-key inferior-lisp-mode-map "\C-c\C-d" 'lisp-describe-sym)
  (define-key inferior-lisp-mode-map "\C-c\C-f"
    'lisp-show-function-documentation)
  (define-key inferior-lisp-mode-map "\C-c\C-v"
    'lisp-show-variable-documentation))

(define-key lisp-mode-map "\M-\C-x"  'lisp-eval-defun)     ; Gnu convention
(define-key lisp-mode-map "\C-x\C-e" 'lisp-eval-last-sexp) ; Gnu convention
(define-key lisp-mode-map "\C-c\C-e" 'lisp-eval-defun)
(define-key lisp-mode-map "\C-c\C-r" 'lisp-eval-region)
(define-key lisp-mode-map "\C-c\C-c" 'lisp-compile-defun)
(define-key lisp-mode-map "\C-c\C-z" 'switch-to-lisp)
(define-key lisp-mode-map "\C-c\C-l" 'lisp-load-file)
(define-key lisp-mode-map "\C-c\C-k" 'lisp-compile-file)  ; "kompile" file
(define-key lisp-mode-map "\C-c\C-a" 'lisp-show-arglist)
(define-key lisp-mode-map "\C-c\C-d" 'lisp-describe-sym)
(define-key lisp-mode-map "\C-c\C-f" 'lisp-show-function-documentation)
(define-key lisp-mode-map "\C-c\C-v" 'lisp-show-variable-documentation)

(defun inferior-lisp-install-letter-bindings ()
  (define-key lisp-mode-map "\C-ce" 'lisp-eval-defun-and-go)
  (define-key lisp-mode-map "\C-cr" 'lisp-eval-region-and-go)
  (define-key lisp-mode-map "\C-cc" 'lisp-compile-defun-and-go)
  (define-key lisp-mode-map "\C-cz" 'switch-to-lisp)
  (define-key lisp-mode-map "\C-cl" 'lisp-load-file)
  (define-key lisp-mode-map "\C-ck" 'lisp-compile-file)
  (define-key lisp-mode-map "\C-ca" 'lisp-show-arglist)
  (define-key lisp-mode-map "\C-cd" 'lisp-describe-sym)
  (define-key lisp-mode-map "\C-cf" 'lisp-show-function-documentation)
  (define-key lisp-mode-map "\C-cv" 'lisp-show-variable-documentation)

  (define-key inferior-lisp-mode-map "\C-cl" 'lisp-load-file)
  (define-key inferior-lisp-mode-map "\C-ck" 'lisp-compile-file)
  (define-key inferior-lisp-mode-map "\C-ca" 'lisp-show-arglist)
  (define-key inferior-lisp-mode-map "\C-cd" 'lisp-describe-sym)
  (define-key inferior-lisp-mode-map "\C-cf" 'lisp-show-function-documentation)
  (define-key inferior-lisp-mode-map "\C-cv"
    'lisp-show-variable-documentation))

;;;###autoload
(defvar inferior-lisp-program "lisp"
  "*Program name for invoking an inferior Lisp with for Inferior Lisp mode.")

;;;###autoload
(defvar inferior-lisp-load-command "(load \"%s\")\n"
  "*Format-string for building a Lisp expression to load a file.
This format string should use `%s' to substitute a file name
and should result in a Lisp expression that will command the inferior Lisp
to load that file.  The default works acceptably on most Lisps.
The string \"(progn (load \\\"%s\\\" :verbose nil :print t) (values))\\n\"
produces cosmetically superior output for this application,
but it works only in Common Lisp.")

;;;###autoload
(defvar inferior-lisp-prompt "^[^> \n]*>+:? *"
  "Regexp to recognise prompts in the Inferior Lisp mode.
Defaults to \"^[^> \\n]*>+:? *\", which works pretty good for Lucid, kcl,
and franz.  This variable is used to initialize `comint-prompt-regexp' in the
Inferior Lisp buffer.

This variable is only used if the variable
`comint-use-prompt-regexp-instead-of-fields' is non-nil.

More precise choices:
Lucid Common Lisp: \"^\\\\(>\\\\|\\\\(->\\\\)+\\\\) *\"
franz: \"^\\\\(->\\\\|<[0-9]*>:\\\\) *\"
kcl: \"^>+ *\"

This is a fine thing to set in your .emacs file.")

(defvar inferior-lisp-buffer nil "*The current inferior-lisp process buffer.

MULTIPLE PROCESS SUPPORT
===========================================================================
To run multiple Lisp processes, you start the first up
with \\[inferior-lisp].  It will be in a buffer named `*inferior-lisp*'.
Rename this buffer with \\[rename-buffer].  You may now start up a new
process with another \\[inferior-lisp].  It will be in a new buffer,
named `*inferior-lisp*'.  You can switch between the different process
buffers with \\[switch-to-buffer].

Commands that send text from source buffers to Lisp processes --
like `lisp-eval-defun' or `lisp-show-arglist' -- have to choose a process
to send to, when you have more than one Lisp process around.  This
is determined by the global variable `inferior-lisp-buffer'.  Suppose you
have three inferior Lisps running:
    Buffer              Process
    foo                 inferior-lisp
    bar                 inferior-lisp<2>
    *inferior-lisp*     inferior-lisp<3>
If you do a \\[lisp-eval-defun] command on some Lisp source code,
what process do you send it to?

- If you're in a process buffer (foo, bar, or *inferior-lisp*),
  you send it to that process.
- If you're in some other buffer (e.g., a source file), you
  send it to the process attached to buffer `inferior-lisp-buffer'.
This process selection is performed by function `inferior-lisp-proc'.

Whenever \\[inferior-lisp] fires up a new process, it resets
`inferior-lisp-buffer' to be the new process's buffer.  If you only run
one process, this does the right thing.  If you run multiple
processes, you can change `inferior-lisp-buffer' to another process
buffer with \\[set-variable].")

;;;###autoload
(defvar inferior-lisp-mode-hook '()
  "*Hook for customising Inferior Lisp mode.")

(put 'inferior-lisp-mode 'mode-class 'special)

(defun inferior-lisp-mode ()
  "Major mode for interacting with an inferior Lisp process.
Runs a Lisp interpreter as a subprocess of Emacs, with Lisp I/O through an
Emacs buffer.  Variable `inferior-lisp-program' controls which Lisp interpreter
is run.  Variables `inferior-lisp-prompt', `inferior-lisp-filter-regexp' and
`inferior-lisp-load-command' can customize this mode for different Lisp
interpreters.

For information on running multiple processes in multiple buffers, see
documentation for variable `inferior-lisp-buffer'.

\\{inferior-lisp-mode-map}

Customisation: Entry to this mode runs the hooks on `comint-mode-hook' and
`inferior-lisp-mode-hook' (in that order).

You can send text to the inferior Lisp process from other buffers containing
Lisp source.
    switch-to-lisp switches the current buffer to the Lisp process buffer.
    lisp-eval-defun sends the current defun to the Lisp process.
    lisp-compile-defun compiles the current defun.
    lisp-eval-region sends the current region to the Lisp process.
    lisp-compile-region compiles the current region.

    Prefixing the lisp-eval/compile-defun/region commands with
    a \\[universal-argument] causes a switch to the Lisp process buffer after sending
    the text.

Commands:
Return after the end of the process' output sends the text from the
    end of process to point.
Return before the end of the process' output copies the sexp ending at point
    to the end of the process' output, and sends it.
Delete converts tabs to spaces as it moves back.
Tab indents for Lisp; with argument, shifts rest
    of expression rigidly with the current line.
C-M-q does Tab on each line starting within following expression.
Paragraphs are separated only by blank lines.  Semicolons start comments.
If you accidentally suspend your process, use \\[comint-continue-subjob]
to continue it."
  (interactive)
  (comint-mode)
  (setq comint-prompt-regexp inferior-lisp-prompt)
  (setq major-mode 'inferior-lisp-mode)
  (setq mode-name "Inferior Lisp")
  (setq mode-line-process '(":%s"))
  (lisp-mode-variables t)
  (use-local-map inferior-lisp-mode-map)    ;c-c c-k for "kompile" file
  (setq comint-get-old-input (function lisp-get-old-input))
  (setq comint-input-filter (function lisp-input-filter))
  (run-hooks 'inferior-lisp-mode-hook))

(defun lisp-get-old-input ()
  "Return a string containing the sexp ending at point."
  (save-excursion
    (let ((end (point)))
      (backward-sexp)
      (buffer-substring (point) end))))

(defun lisp-input-filter (str)
  "t if STR does not match `inferior-lisp-filter-regexp'."
  (not (string-match inferior-lisp-filter-regexp str)))

;;;###autoload
(defun inferior-lisp (cmd)
  "Run an inferior Lisp process, input and output via buffer `*inferior-lisp*'.
If there is a process already running in `*inferior-lisp*', just switch
to that buffer.
With argument, allows you to edit the command line (default is value
of `inferior-lisp-program').  Runs the hooks from
`inferior-lisp-mode-hook' (after the `comint-mode-hook' is run).
\(Type \\[describe-mode] in the process buffer for a list of commands.)"
  (interactive (list (if current-prefix-arg
			 (read-string "Run lisp: " inferior-lisp-program)
		       inferior-lisp-program)))
  (if (not (comint-check-proc "*inferior-lisp*"))
      (let ((cmdlist (split-string cmd)))
	(set-buffer (apply (function make-comint)
			   "inferior-lisp" (car cmdlist) nil (cdr cmdlist)))
	(inferior-lisp-mode)))
  (setq inferior-lisp-buffer "*inferior-lisp*")
  (pop-to-buffer "*inferior-lisp*"))

;;;###autoload (add-hook 'same-window-buffer-names "*inferior-lisp*")

;;;###autoload
(defalias 'run-lisp 'inferior-lisp)

(defun lisp-eval-region (start end &optional and-go)
  "Send the current region to the inferior Lisp process.
Prefix argument means switch to the Lisp buffer afterwards."
  (interactive "r\nP")
  (comint-send-region (inferior-lisp-proc) start end)
  (comint-send-string (inferior-lisp-proc) "\n")
  (if and-go (switch-to-lisp t)))

(defun lisp-eval-defun (&optional and-go)
  "Send the current defun to the inferior Lisp process.
Prefix argument means switch to the Lisp buffer afterwards."
  (interactive "P")
  (save-excursion
    (end-of-defun)
    (skip-chars-backward " \t\n\r\f") ;  Makes allegro happy
    (let ((end (point)))
      (beginning-of-defun)
      (lisp-eval-region (point) end)))
  (if and-go (switch-to-lisp t)))

(defun lisp-eval-last-sexp (&optional and-go)
  "Send the previous sexp to the inferior Lisp process.
Prefix argument means switch to the Lisp buffer afterwards."
  (interactive "P")
  (lisp-eval-region (save-excursion (backward-sexp) (point)) (point) and-go))

;;; Common Lisp COMPILE sux.
(defun lisp-compile-region (start end &optional and-go)
  "Compile the current region in the inferior Lisp process.
Prefix argument means switch to the Lisp buffer afterwards."
  (interactive "r\nP")
  (comint-send-string
   (inferior-lisp-proc)
   (format "(funcall (compile nil `(lambda () (progn 'compile %s))))\n"
	   (buffer-substring start end)))
  (if and-go (switch-to-lisp t)))

(defun lisp-compile-defun (&optional and-go)
  "Compile the current defun in the inferior Lisp process.
Prefix argument means switch to the Lisp buffer afterwards."
  (interactive "P")
  (save-excursion
    (end-of-defun)
    (skip-chars-backward " \t\n\r\f") ;  Makes allegro happy
    (let ((e (point)))
      (beginning-of-defun)
      (lisp-compile-region (point) e)))
  (if and-go (switch-to-lisp t)))

(defun switch-to-lisp (eob-p)
  "Switch to the inferior Lisp process buffer.
With argument, positions cursor at end of buffer."
  (interactive "P")
  (if (get-buffer-process inferior-lisp-buffer)
      (let ((pop-up-frames
	     ;; Be willing to use another frame
	     ;; that already has the window in it.
	     (or pop-up-frames
		 (get-buffer-window inferior-lisp-buffer t))))
	(pop-to-buffer inferior-lisp-buffer))
      (run-lisp inferior-lisp-program))
  (when eob-p
	 (push-mark)
    (goto-char (point-max))))

(defun lisp-eval-region-and-go (start end)
  "Send the current region to the inferior Lisp, and switch to its buffer."
  (interactive "r")
  (lisp-eval-region start end t))

(defun lisp-eval-defun-and-go ()
  "Send the current defun to the inferior Lisp, and switch to its buffer."
  (interactive)
  (lisp-eval-defun t))

(defun lisp-compile-region-and-go (start end)
  "Compile the current region in the inferior Lisp, and switch to its buffer."
  (interactive "r")
  (lisp-compile-region start end t))

(defun lisp-compile-defun-and-go ()
  "Compile the current defun in the inferior Lisp, and switch to its buffer."
  (interactive)
  (lisp-compile-defun t))

;;; (defun lisp-compile-sexp (start end)
;;;   "Compile the s-expression bounded by START and END in the inferior lisp.
;;; If the sexp isn't a DEFUN form, it is evaluated instead."
;;;   (cond ((looking-at "(defun\\s +")
;;; 	 (goto-char (match-end 0))
;;; 	 (let ((name-start (point)))
;;; 	   (forward-sexp 1)
;;; 	   (process-send-string "inferior-lisp"
;;; 				(format "(compile '%s #'(lambda "
;;; 					(buffer-substring name-start
;;; 							  (point)))))
;;; 	 (let ((body-start (point)))
;;; 	   (goto-char start) (forward-sexp 1) ; Can't use end-of-defun.
;;; 	   (process-send-region "inferior-lisp"
;;; 				(buffer-substring body-start (point))))
;;; 	 (process-send-string "inferior-lisp" ")\n"))
;;; 	(t (lisp-eval-region start end)))))
;;;
;;; (defun lisp-compile-region (start end)
;;;   "Each s-expression in the current region is compiled (if a DEFUN)
;;; or evaluated (if not) in the inferior lisp."
;;;   (interactive "r")
;;;   (save-excursion
;;;     (goto-char start) (end-of-defun) (beginning-of-defun) ; error check
;;;     (if (< (point) start) (error "region begins in middle of defun"))
;;;     (goto-char start)
;;;     (let ((s start))
;;;       (end-of-defun)
;;;       (while (<= (point) end) ; Zip through
;;; 	(lisp-compile-sexp s (point)) ; compiling up defun-sized chunks.
;;; 	(setq s (point))
;;; 	(end-of-defun))
;;;       (if (< s end) (lisp-compile-sexp s end)))))
;;;
;;; End of HS-style code

(defvar lisp-prev-l/c-dir/file nil
  "Record last directory and file used in loading or compiling.
This holds a cons cell of the form `(DIRECTORY . FILE)'
describing the last `lisp-load-file' or `lisp-compile-file' command.")

(defvar lisp-source-modes '(lisp-mode)
  "*Used to determine if a buffer contains Lisp source code.
If it's loaded into a buffer that is in one of these major modes, it's
considered a Lisp source file by `lisp-load-file' and `lisp-compile-file'.
Used by these commands to determine defaults.")

(defun lisp-load-file (file-name)
  "Load a Lisp file into the inferior Lisp process."
  (interactive (comint-get-source "Load Lisp file: " lisp-prev-l/c-dir/file
				  lisp-source-modes nil)) ; NIL because LOAD
					; doesn't need an exact name
  (comint-check-source file-name) ; Check to see if buffer needs saved.
  (setq lisp-prev-l/c-dir/file (cons (file-name-directory    file-name)
				     (file-name-nondirectory file-name)))
  (comint-send-string (inferior-lisp-proc)
		      (format inferior-lisp-load-command file-name))
  (switch-to-lisp t))

(defun lisp-compile-file (file-name)
  "Compile a Lisp file in the inferior Lisp process."
  (interactive (comint-get-source "Compile Lisp file: " lisp-prev-l/c-dir/file
				  lisp-source-modes nil)) ; NIL = don't need
					; suffix .lisp
  (comint-check-source file-name) ; Check to see if buffer needs saved.
  (setq lisp-prev-l/c-dir/file (cons (file-name-directory    file-name)
				     (file-name-nondirectory file-name)))
  (comint-send-string (inferior-lisp-proc) (concat "(compile-file \""
						   file-name
						   "\"\)\n"))
  (switch-to-lisp t))

(defvar lisp-function-doc-command
  "(let ((fn '%s))
     (format t \"Documentation for ~a:~&~a\"
	     fn (documentation fn 'function))
     (values))\n"
  "Command to query inferior Lisp for a function's documentation.")

(defvar lisp-var-doc-command
  "(let ((v '%s))
     (format t \"Documentation for ~a:~&~a\"
	     v (documentation v 'variable))
     (values))\n"
  "Command to query inferior Lisp for a variable's documentation.")

(defvar lisp-arglist-command
  "(let ((fn '%s))
     (format t \"Arglist for ~a: ~a\" fn (arglist fn))
     (values))\n"
  "Command to query inferior Lisp for a function's arglist.")

(defvar lisp-describe-sym-command
  "(describe '%s)\n"
  "Command to query inferior Lisp for a variable's documentation.")

;;; Reads a string from the user.
(defun lisp-symprompt (prompt default)
  (list (let* ((prompt (if default
			   (format "%s (default %s): " prompt default)
			 (concat prompt ": ")))
	       (ans (read-string prompt)))
	  (if (zerop (length ans)) default ans))))

;;; Adapted from function-called-at-point in help.el.
(defun lisp-fn-called-at-pt ()
  "Returns the name of the function called in the current call.
The value is nil if it can't find one."
  (condition-case nil
      (save-excursion
	(save-restriction
	  (narrow-to-region (max (point-min) (- (point) 1000)) (point-max))
	  (backward-up-list 1)
	  (forward-char 1)
	  (let ((obj (read (current-buffer))))
	    (and (symbolp obj) obj))))
    (error nil)))

;;; Adapted from variable-at-point in help.el.
(defun lisp-var-at-pt ()
  (condition-case ()
      (save-excursion
	(forward-sexp -1)
	(skip-chars-forward "'")
	(let ((obj (read (current-buffer))))
	  (and (symbolp obj) obj)))
    (error nil)))

(defun lisp-show-function-documentation (fn)
  "Send a command to the inferior Lisp to give documentation for function FN.
See variable `lisp-function-doc-command'."
  (interactive (lisp-symprompt "Function doc" (lisp-fn-called-at-pt)))
  (comint-proc-query (inferior-lisp-proc)
		     (format lisp-function-doc-command fn)))

(defun lisp-show-variable-documentation (var)
  "Send a command to the inferior Lisp to give documentation for function FN.
See variable `lisp-var-doc-command'."
  (interactive (lisp-symprompt "Variable doc" (lisp-var-at-pt)))
  (comint-proc-query (inferior-lisp-proc) (format lisp-var-doc-command var)))

(defun lisp-show-arglist (fn)
  "Send a query to the inferior Lisp for the arglist for function FN.
See variable `lisp-arglist-command'."
  (interactive (lisp-symprompt "Arglist" (lisp-fn-called-at-pt)))
  (comint-proc-query (inferior-lisp-proc) (format lisp-arglist-command fn)))

(defun lisp-describe-sym (sym)
  "Send a command to the inferior Lisp to describe symbol SYM.
See variable `lisp-describe-sym-command'."
  (interactive (lisp-symprompt "Describe" (lisp-var-at-pt)))
  (comint-proc-query (inferior-lisp-proc)
		     (format lisp-describe-sym-command sym)))

;;  "Returns the current inferior Lisp process.
;; See variable `inferior-lisp-buffer'."
(defun inferior-lisp-proc ()
  (let ((proc (get-buffer-process (if (eq major-mode 'inferior-lisp-mode)
				      (current-buffer)
				    inferior-lisp-buffer))))
    (or proc
	(error "No Lisp subprocess; see variable `inferior-lisp-buffer'"))))

(defvar inferior-lisp-load-hook nil
  "This hook is run when the library `inf-lisp' is loaded.
This is a good place to put keybindings.")

(run-hooks 'inferior-lisp-load-hook)

(provide 'inf-lisp)