--- /dev/null
+;;; Major mode for editing Python programs, version 1.10
+;; by: Tim Peters <tim@ksr.com>
+;; after an original idea by: Michael A. Guravage
+;;
+;; Copyright (c) 1992,1993,1994 Tim Peters
+;;
+;; This software is provided as-is, without express or implied warranty.
+;; Permission to use, copy, modify, distribute or sell this software,
+;; without fee, for any purpose and by any individual or organization, is
+;; hereby granted, provided that the above copyright notice and this
+;; paragraph appear in all copies.
+;;
+;;
+;; The following statements, placed in your .emacs file or site-init.el,
+;; will cause this file to be autoloaded, and python-mode invoked, when
+;; visiting .py files (assuming the file is in your load-path):
+;;
+;; (autoload 'python-mode "python-mode" "" t)
+;; (setq auto-mode-alist
+;; (cons '("\\.py$" . python-mode) auto-mode-alist))
+
+(provide 'python-mode)
+
+;;; Differentiate between Emacs 18, Lucid Emacs, and Emacs 19.
+;;; This seems to be the standard way of checking this.
+
+(setq py-this-is-lucid-emacs-p (string-match "Lucid" emacs-version))
+(setq py-this-is-emacs-19-p
+ (and
+ (not py-this-is-lucid-emacs-p)
+ (string-match "^19\\." emacs-version)))
+
+;;; Constants and variables
+
+(defvar py-python-command "python"
+ "*Shell command used to start Python interpreter.")
+
+(defvar py-indent-offset 8 ; argue with Guido <grin>
+ "*Indentation increment.
+Note that `\\[py-guess-indent-offset]' can usually guess a good value when you're
+editing someone else's Python code.")
+
+(defvar py-block-comment-prefix "##"
+ "*String used by py-comment-region to comment out a block of code.
+This should follow the convention for non-indenting comment lines so
+that the indentation commands won't get confused (i.e., the string
+should be of the form `#x...' where `x' is not a blank or a tab, and
+`...' is arbitrary).")
+
+(defvar py-scroll-process-buffer t
+ "*Scroll Python process buffer as output arrives.
+If nil, the Python process buffer acts, with respect to scrolling, like
+Shell-mode buffers normally act. This is surprisingly complicated and
+so won't be explained here; in fact, you can't get the whole story
+without studying the Emacs C code.
+
+If non-nil, the behavior is different in two respects (which are
+slightly inaccurate in the interest of brevity):
+
+ - If the buffer is in a window, and you left point at its end, the
+ window will scroll as new output arrives, and point will move to the
+ buffer's end, even if the window is not the selected window (that
+ being the one the cursor is in). The usual behavior for shell-mode
+ windows is not to scroll, and to leave point where it was, if the
+ buffer is in a window other than the selected window.
+
+ - If the buffer is not visible in any window, and you left point at
+ its end, the buffer will be popped into a window as soon as more
+ output arrives. This is handy if you have a long-running
+ computation and don't want to tie up screen area waiting for the
+ output. The usual behavior for a shell-mode buffer is to stay
+ invisible until you explicitly visit it.
+
+Note the `and if you left point at its end' clauses in both of the
+above: you can `turn off' the special behaviors while output is in
+progress, by visiting the Python buffer and moving point to anywhere
+besides the end. Then the buffer won't scroll, point will remain where
+you leave it, and if you hide the buffer it will stay hidden until you
+visit it again. You can enable and disable the special behaviors as
+often as you like, while output is in progress, by (respectively) moving
+point to, or away from, the end of the buffer.
+
+Warning: If you expect a large amount of output, you'll probably be
+happier setting this option to nil.
+
+Obscure: `End of buffer' above should really say `at or beyond the
+process mark', but if you know what that means you didn't need to be
+told <grin>.")
+
+(defvar py-temp-directory
+ (let ( (ok '(lambda (x)
+ (and x
+ (setq x (expand-file-name x)) ; always true
+ (file-directory-p x)
+ (file-writable-p x)
+ x))))
+ (or (funcall ok (getenv "TMPDIR"))
+ (funcall ok "/usr/tmp")
+ (funcall ok "/tmp")
+ (funcall ok ".")
+ (error
+ "Couldn't find a usable temp directory -- set py-temp-directory")))
+ "*Directory used for temp files created by a *Python* process.
+By default, the first directory from this list that exists and that you
+can write into: the value (if any) of the environment variable TMPDIR,
+/usr/tmp, /tmp, or the current directory.")
+
+;; have to bind py-file-queue before installing the kill-emacs hook
+(defvar py-file-queue nil
+ "Queue of Python temp files awaiting execution.
+Currently-active file is at the head of the list.")
+
+;; define a mode-specific abbrev table for those who use such things
+(defvar python-mode-abbrev-table nil
+ "Abbrev table in use in python-mode buffers.")
+(define-abbrev-table 'python-mode-abbrev-table nil)
+
+;; arrange to kill temp files no matter what
+(if (or py-this-is-emacs-19-p py-this-is-lucid-emacs-p)
+ (add-hook 'kill-emacs-hook 'py-kill-emacs-hook)
+ ;; have to trust that other people are as respectful of our hook
+ ;; fiddling as we are of theirs
+ (if (boundp 'py-inherited-kill-emacs-hook)
+ ;; we were loaded before -- trust others not to have screwed us
+ ;; in the meantime (no choice, really)
+ nil
+ ;; else arrange for our hook to run theirs
+ (setq py-inherited-kill-emacs-hook kill-emacs-hook)
+ (setq kill-emacs-hook 'py-kill-emacs-hook)))
+
+(defvar python-mode-hook nil
+ "*Hook called by `python-mode'.")
+
+(and (fboundp 'make-obsolete-variable)
+ (make-obsolete-variable 'py-mode-hook 'python-mode-hook))
+
+(defvar py-beep-if-tab-change t
+ "*Ring the bell if tab-width is changed.
+If a comment of the form
+\t# vi:set tabsize=<number>:
+is found before the first code line when the file is entered, and
+the current value of (the general Emacs variable) tab-width does not
+equal <number>, tab-width is set to <number>, a message saying so is
+displayed in the echo area, and if py-beep-if-tab-change is non-nil the
+Emacs bell is also rung as a warning.")
+
+(defvar py-mode-map nil "Keymap used in Python mode buffers.")
+(if py-mode-map
+ ()
+ (setq py-mode-map (make-sparse-keymap))
+
+ ;; shadow global bindings for newline-and-indent w/ the py- version
+ (mapcar (function (lambda (key)
+ (define-key
+ py-mode-map key 'py-newline-and-indent)))
+ (where-is-internal 'newline-and-indent))
+
+ (mapcar (function
+ (lambda (x)
+ (define-key py-mode-map (car x) (cdr x))))
+ '( ("\C-c\C-c" . py-execute-buffer)
+ ("\C-c|" . py-execute-region)
+ ("\C-c!" . py-shell)
+ ("\177" . py-delete-char)
+ ("\n" . py-newline-and-indent)
+ ("\C-c:" . py-guess-indent-offset)
+ ("\C-c\t" . py-indent-region)
+ ("\C-c<" . py-shift-region-left)
+ ("\C-c>" . py-shift-region-right)
+ ("\C-c\C-n" . py-next-statement)
+ ("\C-c\C-p" . py-previous-statement)
+ ("\C-c\C-u" . py-goto-block-up)
+ ("\C-c\C-b" . py-mark-block)
+ ("\C-c#" . py-comment-region)
+ ("\C-c?" . py-describe-mode)
+ ("\C-c\C-hm" . py-describe-mode)
+ ("\e\C-a" . beginning-of-python-def-or-class)
+ ("\e\C-e" . end-of-python-def-or-class)
+ ( "\e\C-h" . mark-python-def-or-class))))
+
+(defvar py-mode-syntax-table nil "Python mode syntax table")
+(if py-mode-syntax-table
+ ()
+ (setq py-mode-syntax-table (make-syntax-table))
+ (mapcar (function
+ (lambda (x) (modify-syntax-entry
+ (car x) (cdr x) py-mode-syntax-table)))
+ '(( ?\( . "()" ) ( ?\) . ")(" )
+ ( ?\[ . "(]" ) ( ?\] . ")[" )
+ ( ?\{ . "(}" ) ( ?\} . "){" )
+ ;; fix operator symbols misassigned in the std table
+ ( ?\$ . "." ) ( ?\% . "." ) ( ?\& . "." )
+ ( ?\* . "." ) ( ?\+ . "." ) ( ?\- . "." )
+ ( ?\/ . "." ) ( ?\< . "." ) ( ?\= . "." )
+ ( ?\> . "." ) ( ?\| . "." )
+ ( ?\_ . "w" ) ; underscore is legit in names
+ ( ?\' . "\"") ; single quote is string quote
+ ( ?\" . "\"" ) ; double quote is string quote too
+ ( ?\` . "$") ; backquote is open and close paren
+ ( ?\# . "<") ; hash starts comment
+ ( ?\n . ">")))) ; newline ends comment
+
+(defconst py-stringlit-re
+ (concat
+ "'\\([^'\n\\]\\|\\\\.\\)*'" ; single-quoted
+ "\\|" ; or
+ "\"\\([^\"\n\\]\\|\\\\.\\)*\"") ; double-quoted
+ "regexp matching a Python string literal")
+
+;; this is tricky because a trailing backslash does not mean
+;; continuation if it's in a comment
+(defconst py-continued-re
+ (concat
+ "\\(" "[^#'\"\n\\]" "\\|" py-stringlit-re "\\)*"
+ "\\\\$")
+ "regexp matching Python lines that are continued via backslash")
+
+(defconst py-blank-or-comment-re "[ \t]*\\($\\|#\\)"
+ "regexp matching blank or comment lines")
+
+;;; General Functions
+
+(defun python-mode ()
+ "Major mode for editing Python files.
+Do `\\[py-describe-mode]' for detailed documentation.
+Knows about Python indentation, tokens, comments and continuation lines.
+Paragraphs are separated by blank lines only.
+
+COMMANDS
+\\{py-mode-map}
+VARIABLES
+
+py-indent-offset\tindentation increment
+py-block-comment-prefix\tcomment string used by py-comment-region
+py-python-command\tshell command to invoke Python interpreter
+py-scroll-process-buffer\talways scroll Python process buffer
+py-temp-directory\tdirectory used for temp files (if needed)
+py-beep-if-tab-change\tring the bell if tab-width is changed"
+ (interactive)
+ (kill-all-local-variables)
+ (setq major-mode 'python-mode
+ mode-name "Python"
+ local-abbrev-table python-mode-abbrev-table)
+ (use-local-map py-mode-map)
+ (set-syntax-table py-mode-syntax-table)
+
+ (mapcar (function (lambda (x)
+ (make-local-variable (car x))
+ (set (car x) (cdr x))))
+ '( (paragraph-separate . "^[ \t]*$")
+ (paragraph-start . "^[ \t]*$")
+ (require-final-newline . t)
+ (comment-start . "# ")
+ (comment-start-skip . "# *")
+ (comment-column . 40)
+ (indent-region-function . py-indent-region)
+ (indent-line-function . py-indent-line)))
+
+ ;; hack to allow overriding the tabsize in the file (see tokenizer.c)
+
+ ;; not sure where the magic comment has to be; to save time searching
+ ;; for a rarity, we give up if it's not found prior to the first
+ ;; executable statement
+ (let ( (case-fold-search nil)
+ (start (point))
+ new-tab-width)
+ (if (re-search-forward
+ "^[ \t]*#[ \t]*vi:set[ \t]+tabsize=\\([0-9]+\\):"
+ (prog2 (py-next-statement 1) (point) (goto-char 1))
+ t)
+ (progn
+ (setq new-tab-width
+ (string-to-int
+ (buffer-substring (match-beginning 1) (match-end 1))))
+ (if (= tab-width new-tab-width)
+ nil
+ (setq tab-width new-tab-width)
+ (message "Caution: tab-width changed to %d" new-tab-width)
+ (if py-beep-if-tab-change (beep)))))
+ (goto-char start))
+
+ (if python-mode-hook
+ (run-hooks 'python-mode-hook)
+ (run-hooks 'py-mode-hook)))
+
+;;; Functions that execute Python commands in a subprocess
+
+(defun py-shell ()
+ "Start an interactive Python interpreter in another window.
+This is like Shell mode, except that Python is running in the window
+instead of a shell. See the `Interactive Shell' and `Shell Mode'
+sections of the Emacs manual for details, especially for the key
+bindings active in the `*Python*' buffer.
+
+See the docs for variable py-scroll-buffer for info on scrolling
+behavior in the process window.
+
+Warning: Don't use an interactive Python if you change sys.ps1 or
+sys.ps2 from their default values, or if you're running code that prints
+`>>> ' or `... ' at the start of a line. Python mode can't distinguish
+your output from Python's output, and assumes that `>>> ' at the start
+of a line is a prompt from Python. Similarly, the Emacs Shell mode code
+assumes that both `>>> ' and `... ' at the start of a line are Python
+prompts. Bad things can happen if you fool either mode.
+
+Warning: If you do any editing *in* the process buffer *while* the
+buffer is accepting output from Python, do NOT attempt to `undo' the
+changes. Some of the output (nowhere near the parts you changed!) may
+be lost if you do. This appears to be an Emacs bug, an unfortunate
+interaction between undo and process filters; the same problem exists in
+non-Python process buffers using the default (Emacs-supplied) process
+filter."
+ (interactive)
+ (if py-this-is-emacs-19-p
+ (progn
+ (require 'comint)
+ (switch-to-buffer-other-window
+ (make-comint "Python" py-python-command)))
+ (progn
+ (require 'shell)
+ (switch-to-buffer-other-window
+ (make-shell "Python" py-python-command))))
+ (make-local-variable 'shell-prompt-pattern)
+ (setq shell-prompt-pattern "^>>> \\|^\\.\\.\\. ")
+ (set-process-filter (get-buffer-process (current-buffer))
+ 'py-process-filter)
+ (set-syntax-table py-mode-syntax-table))
+
+(defun py-execute-region (start end)
+ "Send the region between START and END to a Python interpreter.
+If there is a *Python* process it is used.
+
+Hint: If you want to execute part of a Python file several times (e.g.,
+perhaps you're developing a function and want to flesh it out a bit at a
+time), use `\\[narrow-to-region]' to restrict the buffer to the region of interest,
+and send the code to a *Python* process via `\\[py-execute-buffer]' instead.
+
+Following are subtleties to note when using a *Python* process:
+
+If a *Python* process is used, the region is copied into a temp file (in
+directory py-temp-directory), and an `execfile' command is sent to
+Python naming that file. If you send regions faster than Python can
+execute them, Python mode will save them into distinct temp files, and
+execute the next one in the queue the next time it sees a `>>> ' prompt
+from Python. Each time this happens, the process buffer is popped into
+a window (if it's not already in some window) so you can see it, and a
+comment of the form
+
+\t## working on region in file <name> ...
+
+is inserted at the end.
+
+Caution: No more than 26 regions can be pending at any given time. This
+limit is (indirectly) inherited from libc's mktemp(3). Python mode does
+not try to protect you from exceeding the limit. It's extremely
+unlikely that you'll get anywhere close to the limit in practice, unless
+you're trying to be a jerk <grin>.
+
+See the `\\[py-shell]' docs for additional warnings."
+ (interactive "r")
+ (or (< start end) (error "Region is empty"))
+ (let ( (pyproc (get-process "Python"))
+ fname)
+ (if (null pyproc)
+ (shell-command-on-region start end py-python-command)
+ ;; else feed it thru a temp file
+ (setq fname (py-make-temp-name))
+ (write-region start end fname nil 'no-msg)
+ (setq py-file-queue (append py-file-queue (list fname)))
+ (if (cdr py-file-queue)
+ (message "File %s queued for execution" fname)
+ ;; else
+ (py-execute-file pyproc fname)))))
+
+(defun py-execute-file (pyproc fname)
+ (py-append-to-process-buffer
+ pyproc
+ (format "## working on region in file %s ...\n" fname))
+ (process-send-string pyproc (format "execfile('%s')\n" fname)))
+
+(defun py-process-filter (pyproc string)
+ (let ( (curbuf (current-buffer))
+ (pbuf (process-buffer pyproc))
+ (pmark (process-mark pyproc))
+ file-finished)
+
+ ;; make sure we switch to a different buffer at least once. if we
+ ;; *don't* do this, then if the process buffer is in the selected
+ ;; window, and point is before the end, and lots of output is coming
+ ;; at a fast pace, then (a) simple cursor-movement commands like
+ ;; C-p, C-n, C-f, C-b, C-a, C-e take an incredibly long time to have
+ ;; a visible effect (the window just doesn't get updated, sometimes
+ ;; for minutes(!)), and (b) it takes about 5x longer to get all the
+ ;; process output (until the next python prompt).
+ ;;
+ ;; #b makes no sense to me at all. #a almost makes sense: unless we
+ ;; actually change buffers, set_buffer_internal in buffer.c doesn't
+ ;; set windows_or_buffers_changed to 1, & that in turn seems to make
+ ;; the Emacs command loop reluctant to update the display. Perhaps
+ ;; the default process filter in process.c's read_process_output has
+ ;; update_mode_lines++ for a similar reason? beats me ...
+ (if (eq curbuf pbuf) ; mysterious ugly hack
+ (set-buffer (get-buffer-create "*scratch*")))
+
+ (set-buffer pbuf)
+ (let* ( (start (point))
+ (goback (< start pmark))
+ (buffer-read-only nil))
+ (goto-char pmark)
+ (insert string)
+ (move-marker pmark (point))
+ (setq file-finished
+ (and py-file-queue
+ (equal ">>> "
+ (buffer-substring
+ (prog2 (beginning-of-line) (point)
+ (goto-char pmark))
+ (point)))))
+ (if goback (goto-char start)
+ ;; else
+ (if py-scroll-process-buffer
+ (let* ( (pop-up-windows t)
+ (pwin (display-buffer pbuf)))
+ (set-window-point pwin (point))))))
+ (set-buffer curbuf)
+ (if file-finished
+ (progn
+ (py-delete-file-silently (car py-file-queue))
+ (setq py-file-queue (cdr py-file-queue))
+ (if py-file-queue
+ (py-execute-file pyproc (car py-file-queue)))))))
+
+(defun py-execute-buffer ()
+ "Send the contents of the buffer to a Python interpreter.
+If there is a *Python* process buffer it is used. If a clipping
+restriction is in effect, only the accessible portion of the buffer is
+sent. A trailing newline will be supplied if needed.
+
+See the `\\[py-execute-region]' docs for an account of some subtleties."
+ (interactive)
+ (py-execute-region (point-min) (point-max)))
+
+
+;;; Functions for Python style indentation
+
+(defun py-delete-char ()
+ "Reduce indentation or delete character.
+If point is at the leftmost column, deletes the preceding newline.
+
+Else if point is at the leftmost non-blank character of a line that is
+neither a continuation line nor a non-indenting comment line, or if
+point is at the end of a blank line, reduces the indentation to match
+that of the line that opened the current block of code. The line that
+opened the block is displayed in the echo area to help you keep track of
+where you are.
+
+Else the preceding character is deleted, converting a tab to spaces if
+needed so that only a single column position is deleted."
+ (interactive "*")
+ (if (or (/= (current-indentation) (current-column))
+ (bolp)
+ (py-continuation-line-p)
+ (looking-at "#[^ \t\n]")) ; non-indenting #
+ (backward-delete-char-untabify 1)
+ ;; else indent the same as the colon line that opened the block
+
+ ;; force non-blank so py-goto-block-up doesn't ignore it
+ (insert-char ?* 1)
+ (backward-char)
+ (let ( (base-indent 0) ; indentation of base line
+ (base-text "") ; and text of base line
+ (base-found-p nil))
+ (condition-case nil ; in case no enclosing block
+ (save-excursion
+ (py-goto-block-up 'no-mark)
+ (setq base-indent (current-indentation)
+ base-text (py-suck-up-leading-text)
+ base-found-p t))
+ (error nil))
+ (delete-char 1) ; toss the dummy character
+ (delete-horizontal-space)
+ (indent-to base-indent)
+ (if base-found-p
+ (message "Closes block: %s" base-text)))))
+
+(defun py-indent-line ()
+ "Fix the indentation of the current line according to Python rules."
+ (interactive)
+ (let* ( (ci (current-indentation))
+ (move-to-indentation-p (<= (current-column) ci))
+ (need (py-compute-indentation)) )
+ (if (/= ci need)
+ (save-excursion
+ (beginning-of-line)
+ (delete-horizontal-space)
+ (indent-to need)))
+ (if move-to-indentation-p (back-to-indentation))))
+
+(defun py-newline-and-indent ()
+ "Strives to act like the Emacs newline-and-indent.
+This is just `strives to' because correct indentation can't be computed
+from scratch for Python code. In general, deletes the whitespace before
+point, inserts a newline, and takes an educated guess as to how you want
+the new line indented."
+ (interactive)
+ (let ( (ci (current-indentation)) )
+ (if (< ci (current-column)) ; if point beyond indentation
+ (newline-and-indent)
+ ;; else try to act like newline-and-indent "normally" acts
+ (beginning-of-line)
+ (insert-char ?\n 1)
+ (move-to-column ci))))
+
+(defun py-compute-indentation ()
+ (save-excursion
+ (beginning-of-line)
+ (cond
+ ;; are we on a continuation line?
+ ( (py-continuation-line-p)
+ (let ( (startpos (point))
+ (open-bracket-pos (py-nesting-level))
+ endpos searching found)
+ (if open-bracket-pos
+ (progn
+ ;; align with first item in list; else a normal
+ ;; indent beyond the line with the open bracket
+ (goto-char (1+ open-bracket-pos)) ; just beyond bracket
+ ;; is the first list item on the same line?
+ (skip-chars-forward " \t")
+ (if (null (memq (following-char) '(?\n ?# ?\\)))
+ ; yes, so line up with it
+ (current-column)
+ ;; first list item on another line, or doesn't exist yet
+ (forward-line 1)
+ (while (and (< (point) startpos)
+ (looking-at "[ \t]*[#\n\\\\]")) ; skip noise
+ (forward-line 1))
+ (if (< (point) startpos)
+ ;; again mimic the first list item
+ (current-indentation)
+ ;; else they're about to enter the first item
+ (goto-char open-bracket-pos)
+ (+ (current-indentation) py-indent-offset))))
+
+ ;; else on backslash continuation line
+ (forward-line -1)
+ (if (py-continuation-line-p) ; on at least 3rd line in block
+ (current-indentation) ; so just continue the pattern
+ ;; else started on 2nd line in block, so indent more.
+ ;; if base line is an assignment with a start on a RHS,
+ ;; indent to 2 beyond the leftmost "="; else skip first
+ ;; chunk of non-whitespace characters on base line, + 1 more
+ ;; column
+ (end-of-line)
+ (setq endpos (point) searching t)
+ (back-to-indentation)
+ (setq startpos (point))
+ ;; look at all "=" from left to right, stopping at first
+ ;; one not nested in a list or string
+ (while searching
+ (skip-chars-forward "^=" endpos)
+ (if (= (point) endpos)
+ (setq searching nil)
+ (forward-char 1)
+ (setq state (parse-partial-sexp startpos (point)))
+ (if (and (zerop (car state)) ; not in a bracket
+ (null (nth 3 state))) ; & not in a string
+ (progn
+ (setq searching nil) ; done searching in any case
+ (setq found
+ (not (or
+ (eq (following-char) ?=)
+ (memq (char-after (- (point) 2))
+ '(?< ?> ?!)))))))))
+ (if (or (not found) ; not an assignment
+ (looking-at "[ \t]*\\\\")) ; <=><spaces><backslash>
+ (progn
+ (goto-char startpos)
+ (skip-chars-forward "^ \t\n")))
+ (1+ (current-column))))))
+
+ ;; not on a continuation line
+
+ ;; if at start of restriction, or on a non-indenting comment line,
+ ;; assume they intended whatever's there
+ ( (or (bobp) (looking-at "[ \t]*#[^ \t\n]"))
+ (current-indentation) )
+
+ ;; else indentation based on that of the statement that precedes
+ ;; us; use the first line of that statement to establish the base,
+ ;; in case the user forced a non-std indentation for the
+ ;; continuation lines (if any)
+ ( t
+ ;; skip back over blank & non-indenting comment lines
+ ;; note: will skip a blank or non-indenting comment line that
+ ;; happens to be a continuation line too
+ (re-search-backward "^[ \t]*\\([^ \t\n#]\\|#[ \t\n]\\)"
+ nil 'move)
+ (py-goto-initial-line)
+ (if (py-statement-opens-block-p)
+ (+ (current-indentation) py-indent-offset)
+ (current-indentation))))))
+
+(defun py-guess-indent-offset (&optional global)
+ "Guess a good value for, and change, py-indent-offset.
+By default (without a prefix arg), makes a buffer-local copy of
+py-indent-offset with the new value. This will not affect any other
+Python buffers. With a prefix arg, changes the global value of
+py-indent-offset. This affects all Python buffers (that don't have
+their own buffer-local copy), both those currently existing and those
+created later in the Emacs session.
+
+Some people use a different value for py-indent-offset than you use.
+There's no excuse for such foolishness, but sometimes you have to deal
+with their ugly code anyway. This function examines the file and sets
+py-indent-offset to what it thinks it was when they created the mess.
+
+Specifically, it searches forward from the statement containing point,
+looking for a line that opens a block of code. py-indent-offset is set
+to the difference in indentation between that line and the Python
+statement following it. If the search doesn't succeed going forward,
+it's tried again going backward."
+ (interactive "P") ; raw prefix arg
+ (let ( new-value
+ (start (point))
+ restart
+ (found nil)
+ colon-indent)
+ (py-goto-initial-line)
+ (while (not (or found (eobp)))
+ (if (re-search-forward ":[ \t]*\\($\\|[#\\]\\)" nil 'move)
+ (progn
+ (setq restart (point))
+ (py-goto-initial-line)
+ (if (py-statement-opens-block-p)
+ (setq found t)
+ (goto-char restart)))))
+ (if found
+ ()
+ (goto-char start)
+ (py-goto-initial-line)
+ (while (not (or found (bobp)))
+ (setq found
+ (and
+ (re-search-backward ":[ \t]*\\($\\|[#\\]\\)" nil 'move)
+ (or (py-goto-initial-line) t) ; always true -- side effect
+ (py-statement-opens-block-p)))))
+ (setq colon-indent (current-indentation)
+ found (and found (zerop (py-next-statement 1)))
+ new-value (- (current-indentation) colon-indent))
+ (goto-char start)
+ (if found
+ (progn
+ (funcall (if global 'kill-local-variable 'make-local-variable)
+ 'py-indent-offset)
+ (setq py-indent-offset new-value)
+ (message "%s value of py-indent-offset set to %d"
+ (if global "Global" "Local")
+ py-indent-offset))
+ (error "Sorry, couldn't guess a value for py-indent-offset"))))
+
+(defun py-shift-region (start end count)
+ (save-excursion
+ (goto-char end) (beginning-of-line) (setq end (point))
+ (goto-char start) (beginning-of-line) (setq start (point))
+ (indent-rigidly start end count)))
+
+(defun py-shift-region-left (start end &optional count)
+ "Shift region of Python code to the left.
+The lines from the line containing the start of the current region up
+to (but not including) the line containing the end of the region are
+shifted to the left, by py-indent-offset columns.
+
+If a prefix argument is given, the region is instead shifted by that
+many columns."
+ (interactive "*r\nP") ; region; raw prefix arg
+ (py-shift-region start end
+ (- (prefix-numeric-value
+ (or count py-indent-offset)))))
+
+(defun py-shift-region-right (start end &optional count)
+ "Shift region of Python code to the right.
+The lines from the line containing the start of the current region up
+to (but not including) the line containing the end of the region are
+shifted to the right, by py-indent-offset columns.
+
+If a prefix argument is given, the region is instead shifted by that
+many columns."
+ (interactive "*r\nP") ; region; raw prefix arg
+ (py-shift-region start end (prefix-numeric-value
+ (or count py-indent-offset))))
+
+(defun py-indent-region (start end &optional indent-offset)
+ "Reindent a region of Python code.
+The lines from the line containing the start of the current region up
+to (but not including) the line containing the end of the region are
+reindented. If the first line of the region has a non-whitespace
+character in the first column, the first line is left alone and the rest
+of the region is reindented with respect to it. Else the entire region
+is reindented with respect to the (closest code or indenting-comment)
+statement immediately preceding the region.
+
+This is useful when code blocks are moved or yanked, when enclosing
+control structures are introduced or removed, or to reformat code using
+a new value for the indentation offset.
+
+If a numeric prefix argument is given, it will be used as the value of
+the indentation offset. Else the value of py-indent-offset will be
+used.
+
+Warning: The region must be consistently indented before this function
+is called! This function does not compute proper indentation from
+scratch (that's impossible in Python), it merely adjusts the existing
+indentation to be correct in context.
+
+Warning: This function really has no idea what to do with non-indenting
+comment lines, and shifts them as if they were indenting comment lines.
+Fixing this appears to require telepathy.
+
+Special cases: whitespace is deleted from blank lines; continuation
+lines are shifted by the same amount their initial line was shifted, in
+order to preserve their relative indentation with respect to their
+initial line; and comment lines beginning in column 1 are ignored."
+
+ (interactive "*r\nP") ; region; raw prefix arg
+ (save-excursion
+ (goto-char end) (beginning-of-line) (setq end (point-marker))
+ (goto-char start) (beginning-of-line)
+ (let ( (py-indent-offset (prefix-numeric-value
+ (or indent-offset py-indent-offset)))
+ (indents '(-1)) ; stack of active indent levels
+ (target-column 0) ; column to which to indent
+ (base-shifted-by 0) ; amount last base line was shifted
+ (indent-base (if (looking-at "[ \t\n]")
+ (py-compute-indentation)
+ 0))
+ ci)
+ (while (< (point) end)
+ (setq ci (current-indentation))
+ ;; figure out appropriate target column
+ (cond
+ ( (or (eq (following-char) ?#) ; comment in column 1
+ (looking-at "[ \t]*$")) ; entirely blank
+ (setq target-column 0))
+ ( (py-continuation-line-p) ; shift relative to base line
+ (setq target-column (+ ci base-shifted-by)))
+ (t ; new base line
+ (if (> ci (car indents)) ; going deeper; push it
+ (setq indents (cons ci indents))
+ ;; else we should have seen this indent before
+ (setq indents (memq ci indents)) ; pop deeper indents
+ (if (null indents)
+ (error "Bad indentation in region, at line %d"
+ (save-restriction
+ (widen)
+ (1+ (count-lines 1 (point)))))))
+ (setq target-column (+ indent-base
+ (* py-indent-offset
+ (- (length indents) 2))))
+ (setq base-shifted-by (- target-column ci))))
+ ;; shift as needed
+ (if (/= ci target-column)
+ (progn
+ (delete-horizontal-space)
+ (indent-to target-column)))
+ (forward-line 1))))
+ (set-marker end nil))
+
+;;; Functions for moving point
+
+(defun py-previous-statement (count)
+ "Go to the start of previous Python statement.
+If the statement at point is the i'th Python statement, goes to the
+start of statement i-COUNT. If there is no such statement, goes to the
+first statement. Returns count of statements left to move.
+`Statements' do not include blank, comment, or continuation lines."
+ (interactive "p") ; numeric prefix arg
+ (if (< count 0) (py-next-statement (- count))
+ (py-goto-initial-line)
+ (let ( start )
+ (while (and
+ (setq start (point)) ; always true -- side effect
+ (> count 0)
+ (zerop (forward-line -1))
+ (py-goto-statement-at-or-above))
+ (setq count (1- count)))
+ (if (> count 0) (goto-char start)))
+ count))
+
+(defun py-next-statement (count)
+ "Go to the start of next Python statement.
+If the statement at point is the i'th Python statement, goes to the
+start of statement i+COUNT. If there is no such statement, goes to the
+last statement. Returns count of statements left to move. `Statements'
+do not include blank, comment, or continuation lines."
+ (interactive "p") ; numeric prefix arg
+ (if (< count 0) (py-previous-statement (- count))
+ (beginning-of-line)
+ (let ( start )
+ (while (and
+ (setq start (point)) ; always true -- side effect
+ (> count 0)
+ (py-goto-statement-below))
+ (setq count (1- count)))
+ (if (> count 0) (goto-char start)))
+ count))
+
+(defun py-goto-block-up (&optional nomark)
+ "Move up to start of current block.
+Go to the statement that starts the smallest enclosing block; roughly
+speaking, this will be the closest preceding statement that ends with a
+colon and is indented less than the statement you started on. If
+successful, also sets the mark to the starting point.
+
+`\\[py-mark-block]' can be used afterward to mark the whole code block, if desired.
+
+If called from a program, the mark will not be set if optional argument
+NOMARK is not nil."
+ (interactive)
+ (let ( (start (point))
+ (found nil)
+ initial-indent)
+ (py-goto-initial-line)
+ ;; if on blank or non-indenting comment line, use the preceding stmt
+ (if (looking-at "[ \t]*\\($\\|#[^ \t\n]\\)")
+ (progn
+ (py-goto-statement-at-or-above)
+ (setq found (py-statement-opens-block-p))))
+ ;; search back for colon line indented less
+ (setq initial-indent (current-indentation))
+ (if (zerop initial-indent)
+ ;; force fast exit
+ (goto-char (point-min)))
+ (while (not (or found (bobp)))
+ (setq found
+ (and
+ (re-search-backward ":[ \t]*\\($\\|[#\\]\\)" nil 'move)
+ (or (py-goto-initial-line) t) ; always true -- side effect
+ (< (current-indentation) initial-indent)
+ (py-statement-opens-block-p))))
+ (if found
+ (progn
+ (or nomark (push-mark start))
+ (back-to-indentation))
+ (goto-char start)
+ (error "Enclosing block not found"))))
+
+(defun beginning-of-python-def-or-class (&optional class)
+ "Move point to start of def (or class, with prefix arg).
+
+Searches back for the closest preceding `def'. If you supply a prefix
+arg, looks for a `class' instead. The docs assume the `def' case; just
+substitute `class' for `def' for the other case.
+
+If point is in a def statement already, and after the `d', simply moves
+point to the start of the statement.
+
+Else (point is not in a def statement, or at or before the `d' of a def
+statement), searches for the closest preceding def statement, and leaves
+point at its start. If no such statement can be found, leaves point at
+the start of the buffer.
+
+Returns t iff a def statement is found by these rules.
+
+Note that doing this command repeatedly will take you closer to the start
+of the buffer each time.
+
+If you want to mark the current def/class, see `\\[mark-python-def-or-class]'."
+ (interactive "P") ; raw prefix arg
+ (let ( (at-or-before-p (<= (current-column) (current-indentation)))
+ (start-of-line (progn (beginning-of-line) (point)))
+ (start-of-stmt (progn (py-goto-initial-line) (point))))
+ (if (or (/= start-of-stmt start-of-line)
+ (not at-or-before-p))
+ (end-of-line)) ; OK to match on this line
+ (re-search-backward (if class "^[ \t]*class\\>" "^[ \t]*def\\>")
+ nil 'move)))
+
+(defun end-of-python-def-or-class (&optional class)
+ "Move point beyond end of def (or class, with prefix arg) body.
+
+By default, looks for an appropriate `def'. If you supply a prefix arg,
+looks for a `class' instead. The docs assume the `def' case; just
+substitute `class' for `def' for the other case.
+
+If point is in a def statement already, this is the def we use.
+
+Else if the def found by `\\[beginning-of-python-def-or-class]' contains the statement you
+started on, that's the def we use.
+
+Else we search forward for the closest following def, and use that.
+
+If a def can be found by these rules, point is moved to the start of the
+line immediately following the def block, and the position of the start
+of the def is returned.
+
+Else point is moved to the end of the buffer, and nil is returned.
+
+Note that doing this command repeatedly will take you closer to the end
+of the buffer each time.
+
+If you want to mark the current def/class, see `\\[mark-python-def-or-class]'."
+ (interactive "P") ; raw prefix arg
+ (let ( (start (progn (py-goto-initial-line) (point)))
+ (which (if class "class" "def"))
+ (state 'not-found))
+ ;; move point to start of appropriate def/class
+ (if (looking-at (concat "[ \t]*" which "\\>")) ; already on one
+ (setq state 'at-beginning)
+ ;; else see if beginning-of-python-def-or-class hits container
+ (if (and (beginning-of-python-def-or-class class)
+ (progn (py-goto-beyond-block)
+ (> (point) start)))
+ (setq state 'at-end)
+ ;; else search forward
+ (goto-char start)
+ (if (re-search-forward (concat "^[ \t]*" which "\\>") nil 'move)
+ (progn (setq state 'at-beginning)
+ (beginning-of-line)))))
+ (cond
+ ((eq state 'at-beginning) (py-goto-beyond-block) t)
+ ((eq state 'at-end) t)
+ ((eq state 'not-found) nil)
+ (t (error "internal error in end-of-python-def-or-class")))))
+
+;;; Functions for marking regions
+
+(defun py-mark-block (&optional extend just-move)
+ "Mark following block of lines. With prefix arg, mark structure.
+Easier to use than explain. It sets the region to an `interesting'
+block of succeeding lines. If point is on a blank line, it goes down to
+the next non-blank line. That will be the start of the region. The end
+of the region depends on the kind of line at the start:
+
+ - If a comment, the region will include all succeeding comment lines up
+ to (but not including) the next non-comment line (if any).
+
+ - Else if a prefix arg is given, and the line begins one of these
+ structures:
+\tif elif else try except finally for while def class
+ the region will be set to the body of the structure, including
+ following blocks that `belong' to it, but excluding trailing blank
+ and comment lines. E.g., if on a `try' statement, the `try' block
+ and all (if any) of the following `except' and `finally' blocks that
+ belong to the `try' structure will be in the region. Ditto for
+ if/elif/else, for/else and while/else structures, and (a bit
+ degenerate, since they're always one-block structures) def and class
+ blocks.
+
+ - Else if no prefix argument is given, and the line begins a Python
+ block (see list above), and the block is not a `one-liner' (i.e., the
+ statement ends with a colon, not with code), the region will include
+ all succeeding lines up to (but not including) the next code
+ statement (if any) that's indented no more than the starting line,
+ except that trailing blank and comment lines are excluded. E.g., if
+ the starting line begins a multi-statement `def' structure, the
+ region will be set to the full function definition, but without any
+ trailing `noise' lines.
+
+ - Else the region will include all succeeding lines up to (but not
+ including) the next blank line, or code or indenting-comment line
+ indented strictly less than the starting line. Trailing indenting
+ comment lines are included in this case, but not trailing blank
+ lines.
+
+A msg identifying the location of the mark is displayed in the echo
+area; or do `\\[exchange-point-and-mark]' to flip down to the end.
+
+If called from a program, optional argument EXTEND plays the role of the
+prefix arg, and if optional argument JUST-MOVE is not nil, just moves to
+the end of the block (& does not set mark or display a msg)."
+
+ (interactive "P") ; raw prefix arg
+ (py-goto-initial-line)
+ ;; skip over blank lines
+ (while (and
+ (looking-at "[ \t]*$") ; while blank line
+ (not (eobp))) ; & somewhere to go
+ (forward-line 1))
+ (if (eobp)
+ (error "Hit end of buffer without finding a non-blank stmt"))
+ (let ( (initial-pos (point))
+ (initial-indent (current-indentation))
+ last-pos ; position of last stmt in region
+ (followers
+ '( (if elif else) (elif elif else) (else)
+ (try except finally) (except except) (finally)
+ (for else) (while else)
+ (def) (class) ) )
+ first-symbol next-symbol)
+
+ (cond
+ ;; if comment line, suck up the following comment lines
+ ((looking-at "[ \t]*#")
+ (re-search-forward "^[ \t]*[^ \t#]" nil 'move) ; look for non-comment
+ (re-search-backward "^[ \t]*#") ; and back to last comment in block
+ (setq last-pos (point)))
+
+ ;; else if line is a block line and EXTEND given, suck up
+ ;; the whole structure
+ ((and extend
+ (setq first-symbol (py-suck-up-first-keyword) )
+ (assq first-symbol followers))
+ (while (and
+ (or (py-goto-beyond-block) t) ; side effect
+ (forward-line -1) ; side effect
+ (setq last-pos (point)) ; side effect
+ (py-goto-statement-below)
+ (= (current-indentation) initial-indent)
+ (setq next-symbol (py-suck-up-first-keyword))
+ (memq next-symbol (cdr (assq first-symbol followers))))
+ (setq first-symbol next-symbol)))
+
+ ;; else if line *opens* a block, search for next stmt indented <=
+ ((py-statement-opens-block-p)
+ (while (and
+ (setq last-pos (point)) ; always true -- side effect
+ (py-goto-statement-below)
+ (> (current-indentation) initial-indent))
+ nil))
+
+ ;; else plain code line; stop at next blank line, or stmt or
+ ;; indenting comment line indented <
+ (t
+ (while (and
+ (setq last-pos (point)) ; always true -- side effect
+ (or (py-goto-beyond-final-line) t)
+ (not (looking-at "[ \t]*$")) ; stop at blank line
+ (or
+ (>= (current-indentation) initial-indent)
+ (looking-at "[ \t]*#[^ \t\n]"))) ; ignore non-indenting #
+ nil)))
+
+ ;; skip to end of last stmt
+ (goto-char last-pos)
+ (py-goto-beyond-final-line)
+
+ ;; set mark & display
+ (if just-move
+ () ; just return
+ (push-mark (point) 'no-msg)
+ (forward-line -1)
+ (message "Mark set after: %s" (py-suck-up-leading-text))
+ (goto-char initial-pos))))
+
+(defun mark-python-def-or-class (&optional class)
+ "Set region to body of def (or class, with prefix arg) enclosing point.
+Pushes the current mark, then point, on the mark ring (all language
+modes do this, but although it's handy it's never documented ...).
+
+In most Emacs language modes, this function bears at least a
+hallucinogenic resemblance to `\\[end-of-python-def-or-class]' and `\\[beginning-of-python-def-or-class]'.
+
+And in earlier versions of Python mode, all 3 were tightly connected.
+Turned out that was more confusing than useful: the `goto start' and
+`goto end' commands are usually used to search through a file, and people
+expect them to act a lot like `search backward' and `search forward'
+string-search commands. But because Python `def' and `class' can nest to
+arbitrary levels, finding the smallest def containing point cannot be
+done via a simple backward search: the def containing point may not be
+the closest preceding def, or even the closest preceding def that's
+indented less. The fancy algorithm required is appropriate for the usual
+uses of this `mark' command, but not for the `goto' variations.
+
+So the def marked by this command may not be the one either of the `goto'
+commands find: If point is on a blank or non-indenting comment line,
+moves back to start of the closest preceding code statement or indenting
+comment line. If this is a `def' statement, that's the def we use. Else
+searches for the smallest enclosing `def' block and uses that. Else
+signals an error.
+
+When an enclosing def is found: The mark is left immediately beyond the
+last line of the def block. Point is left at the start of the def,
+except that: if the def is preceded by a number of comment lines
+followed by (at most) one optional blank line, point is left at the start
+of the comments; else if the def is preceded by a blank line, point is
+left at its start.
+
+The intent is to mark the containing def/class and its associated
+documentation, to make moving and duplicating functions and classes
+pleasant."
+ (interactive "P") ; raw prefix arg
+ (let ( (start (point))
+ (which (if class "class" "def")))
+ (push-mark start)
+ (if (not (py-go-up-tree-to-keyword which))
+ (progn (goto-char start)
+ (error "Enclosing %s not found" which))
+ ;; else enclosing def/class found
+ (setq start (point))
+ (py-goto-beyond-block)
+ (push-mark (point))
+ (goto-char start)
+ (if (zerop (forward-line -1)) ; if there is a preceding line
+ (progn
+ (if (looking-at "[ \t]*$") ; it's blank
+ (setq start (point)) ; so reset start point
+ (goto-char start)) ; else try again
+ (if (zerop (forward-line -1))
+ (if (looking-at "[ \t]*#") ; a comment
+ ;; look back for non-comment line
+ ;; tricky: note that the regexp matches a blank
+ ;; line, cuz \n is in the 2nd character class
+ (and
+ (re-search-backward "^[ \t]*[^ \t#]" nil 'move)
+ (forward-line 1))
+ ;; no comment, so go back
+ (goto-char start))))))))
+
+(defun py-comment-region (start end &optional uncomment-p)
+ "Comment out region of code; with prefix arg, uncomment region.
+The lines from the line containing the start of the current region up
+to (but not including) the line containing the end of the region are
+commented out, by inserting the string py-block-comment-prefix at the
+start of each line. With a prefix arg, removes py-block-comment-prefix
+from the start of each line instead."
+ (interactive "*r\nP") ; region; raw prefix arg
+ (goto-char end) (beginning-of-line) (setq end (point))
+ (goto-char start) (beginning-of-line) (setq start (point))
+ (let ( (prefix-len (length py-block-comment-prefix)) )
+ (save-excursion
+ (save-restriction
+ (narrow-to-region start end)
+ (while (not (eobp))
+ (if uncomment-p
+ (and (string= py-block-comment-prefix
+ (buffer-substring
+ (point) (+ (point) prefix-len)))
+ (delete-char prefix-len))
+ (insert py-block-comment-prefix))
+ (forward-line 1))))))
+
+;;; Documentation functions
+
+;; dump the long form of the mode blurb; does the usual doc escapes,
+;; plus lines of the form ^[vc]:name$ to suck variable & command
+;; docs out of the right places, along with the keys they're on &
+;; current values
+(defun py-dump-help-string (str)
+ (with-output-to-temp-buffer "*Help*"
+ (let ( (locals (buffer-local-variables))
+ funckind funcname func funcdoc
+ (start 0) mstart end
+ keys )
+ (while (string-match "^%\\([vc]\\):\\(.+\\)\n" str start)
+ (setq mstart (match-beginning 0) end (match-end 0)
+ funckind (substring str (match-beginning 1) (match-end 1))
+ funcname (substring str (match-beginning 2) (match-end 2))
+ func (intern funcname))
+ (princ (substitute-command-keys (substring str start mstart)))
+ (cond
+ ( (equal funckind "c") ; command
+ (setq funcdoc (documentation func)
+ keys (concat
+ "Key(s): "
+ (mapconcat 'key-description
+ (where-is-internal func py-mode-map)
+ ", "))))
+ ( (equal funckind "v") ; variable
+ (setq funcdoc (substitute-command-keys
+ (get func 'variable-documentation))
+ keys (if (assq func locals)
+ (concat
+ "Local/Global values: "
+ (prin1-to-string (symbol-value func))
+ " / "
+ (prin1-to-string (default-value func)))
+ (concat
+ "Value: "
+ (prin1-to-string (symbol-value func))))))
+ ( t ; unexpected
+ (error "Error in py-dump-help-string, tag `%s'" funckind)))
+ (princ (format "\n-> %s:\t%s\t%s\n\n"
+ (if (equal funckind "c") "Command" "Variable")
+ funcname keys))
+ (princ funcdoc)
+ (terpri)
+ (setq start end))
+ (princ (substitute-command-keys (substring str start))))
+ (print-help-return-message)))
+
+(defun py-describe-mode ()
+ "Dump long form of Python-mode docs."
+ (interactive)
+ (py-dump-help-string "Major mode for editing Python files.
+Knows about Python indentation, tokens, comments and continuation lines.
+Paragraphs are separated by blank lines only.
+
+Major sections below begin with the string `@'; specific function and
+variable docs begin with `->'.
+
+@EXECUTING PYTHON CODE
+
+\\[py-execute-buffer]\tsends the entire buffer to the Python interpreter
+\\[py-execute-region]\tsends the current region
+\\[py-shell]\tstarts a Python interpreter window; this will be used by
+\tsubsequent \\[py-execute-buffer] or \\[py-execute-region] commands
+%c:py-execute-buffer
+%c:py-execute-region
+%c:py-shell
+
+@VARIABLES
+
+py-indent-offset\tindentation increment
+py-block-comment-prefix\tcomment string used by py-comment-region
+
+py-python-command\tshell command to invoke Python interpreter
+py-scroll-process-buffer\talways scroll Python process buffer
+py-temp-directory\tdirectory used for temp files (if needed)
+
+py-beep-if-tab-change\tring the bell if tab-width is changed
+%v:py-indent-offset
+%v:py-block-comment-prefix
+%v:py-python-command
+%v:py-scroll-process-buffer
+%v:py-temp-directory
+%v:py-beep-if-tab-change
+
+@KINDS OF LINES
+
+Each physical line in the file is either a `continuation line' (the
+preceding line ends with a backslash that's not part of a comment, or the
+paren/bracket/brace nesting level at the start of the line is non-zero,
+or both) or an `initial line' (everything else).
+
+An initial line is in turn a `blank line' (contains nothing except
+possibly blanks or tabs), a `comment line' (leftmost non-blank character
+is `#'), or a `code line' (everything else).
+
+Comment Lines
+
+Although all comment lines are treated alike by Python, Python mode
+recognizes two kinds that act differently with respect to indentation.
+
+An `indenting comment line' is a comment line with a blank, tab or
+nothing after the initial `#'. The indentation commands (see below)
+treat these exactly as if they were code lines: a line following an
+indenting comment line will be indented like the comment line. All
+other comment lines (those with a non-whitespace character immediately
+following the initial `#') are `non-indenting comment lines', and their
+indentation is ignored by the indentation commands.
+
+Indenting comment lines are by far the usual case, and should be used
+whenever possible. Non-indenting comment lines are useful in cases like
+these:
+
+\ta = b # a very wordy single-line comment that ends up being
+\t #... continued onto another line
+
+\tif a == b:
+##\t\tprint 'panic!' # old code we've `commented out'
+\t\treturn a
+
+Since the `#...' and `##' comment lines have a non-whitespace character
+following the initial `#', Python mode ignores them when computing the
+proper indentation for the next line.
+
+Continuation Lines and Statements
+
+The Python-mode commands generally work on statements instead of on
+individual lines, where a `statement' is a comment or blank line, or a
+code line and all of its following continuation lines (if any)
+considered as a single logical unit. The commands in this mode
+generally (when it makes sense) automatically move to the start of the
+statement containing point, even if point happens to be in the middle of
+some continuation line.
+
+
+@INDENTATION
+
+Primarily for entering new code:
+\t\\[indent-for-tab-command]\t indent line appropriately
+\t\\[py-newline-and-indent]\t insert newline, then indent
+\t\\[py-delete-char]\t reduce indentation, or delete single character
+
+Primarily for reindenting existing code:
+\t\\[py-guess-indent-offset]\t guess py-indent-offset from file content; change locally
+\t\\[universal-argument] \\[py-guess-indent-offset]\t ditto, but change globally
+
+\t\\[py-indent-region]\t reindent region to match its context
+\t\\[py-shift-region-left]\t shift region left by py-indent-offset
+\t\\[py-shift-region-right]\t shift region right by py-indent-offset
+
+Unlike most programming languages, Python uses indentation, and only
+indentation, to specify block structure. Hence the indentation supplied
+automatically by Python-mode is just an educated guess: only you know
+the block structure you intend, so only you can supply correct
+indentation.
+
+The \\[indent-for-tab-command] and \\[py-newline-and-indent] keys try to suggest plausible indentation, based on
+the indentation of preceding statements. E.g., assuming
+py-indent-offset is 4, after you enter
+\tif a > 0: \\[py-newline-and-indent]
+the cursor will be moved to the position of the `_' (_ is not a
+character in the file, it's just used here to indicate the location of
+the cursor):
+\tif a > 0:
+\t _
+If you then enter `c = d' \\[py-newline-and-indent], the cursor will move
+to
+\tif a > 0:
+\t c = d
+\t _
+Python-mode cannot know whether that's what you intended, or whether
+\tif a > 0:
+\t c = d
+\t_
+was your intent. In general, Python-mode either reproduces the
+indentation of the (closest code or indenting-comment) preceding
+statement, or adds an extra py-indent-offset blanks if the preceding
+statement has `:' as its last significant (non-whitespace and non-
+comment) character. If the suggested indentation is too much, use
+\\[py-delete-char] to reduce it.
+
+Continuation lines are given extra indentation. If you don't like the
+suggested indentation, change it to something you do like, and Python-
+mode will strive to indent later lines of the statement in the same way.
+
+If a line is a continuation line by virtue of being in an unclosed
+paren/bracket/brace structure (`list', for short), the suggested
+indentation depends on whether the current line contains the first item
+in the list. If it does, it's indented py-indent-offset columns beyond
+the indentation of the line containing the open bracket. If you don't
+like that, change it by hand. The remaining items in the list will mimic
+whatever indentation you give to the first item.
+
+If a line is a continuation line because the line preceding it ends with
+a backslash, the third and following lines of the statement inherit their
+indentation from the line preceding them. The indentation of the second
+line in the statement depends on the form of the first (base) line: if
+the base line is an assignment statement with anything more interesting
+than the backslash following the leftmost assigning `=', the second line
+is indented two columns beyond that `='. Else it's indented to two
+columns beyond the leftmost solid chunk of non-whitespace characters on
+the base line.
+
+Warning: indent-region should not normally be used! It calls \\[indent-for-tab-command]
+repeatedly, and as explained above, \\[indent-for-tab-command] can't guess the block
+structure you intend.
+%c:indent-for-tab-command
+%c:py-newline-and-indent
+%c:py-delete-char
+
+
+The next function may be handy when editing code you didn't write:
+%c:py-guess-indent-offset
+
+
+The remaining `indent' functions apply to a region of Python code. They
+assume the block structure (equals indentation, in Python) of the region
+is correct, and alter the indentation in various ways while preserving
+the block structure:
+%c:py-indent-region
+%c:py-shift-region-left
+%c:py-shift-region-right
+
+@MARKING & MANIPULATING REGIONS OF CODE
+
+\\[py-mark-block]\t mark block of lines
+\\[mark-python-def-or-class]\t mark smallest enclosing def
+\\[universal-argument] \\[mark-python-def-or-class]\t mark smallest enclosing class
+\\[py-comment-region]\t comment out region of code
+\\[universal-argument] \\[py-comment-region]\t uncomment region of code
+%c:py-mark-block
+%c:mark-python-def-or-class
+%c:py-comment-region
+
+@MOVING POINT
+
+\\[py-previous-statement]\t move to statement preceding point
+\\[py-next-statement]\t move to statement following point
+\\[py-goto-block-up]\t move up to start of current block
+\\[beginning-of-python-def-or-class]\t move to start of def
+\\[universal-argument] \\[beginning-of-python-def-or-class]\t move to start of class
+\\[end-of-python-def-or-class]\t move to end of def
+\\[universal-argument] \\[end-of-python-def-or-class]\t move to end of class
+
+The first two move to one statement beyond the statement that contains
+point. A numeric prefix argument tells them to move that many
+statements instead. Blank lines, comment lines, and continuation lines
+do not count as `statements' for these commands. So, e.g., you can go
+to the first code statement in a file by entering
+\t\\[beginning-of-buffer]\t to move to the top of the file
+\t\\[py-next-statement]\t to skip over initial comments and blank lines
+Or do `\\[py-previous-statement]' with a huge prefix argument.
+%c:py-previous-statement
+%c:py-next-statement
+%c:py-goto-block-up
+%c:beginning-of-python-def-or-class
+%c:end-of-python-def-or-class
+
+@LITTLE-KNOWN EMACS COMMANDS PARTICULARLY USEFUL IN PYTHON MODE
+
+`\\[indent-new-comment-line]' is handy for entering a multi-line comment.
+
+`\\[set-selective-display]' with a `small' prefix arg is ideally suited for viewing the
+overall class and def structure of a module.
+
+`\\[back-to-indentation]' moves point to a line's first non-blank character.
+
+`\\[indent-relative]' is handy for creating odd indentation.
+
+@OTHER EMACS HINTS
+
+If you don't like the default value of a variable, change its value to
+whatever you do like by putting a `setq' line in your .emacs file.
+E.g., to set the indentation increment to 4, put this line in your
+.emacs:
+\t(setq py-indent-offset 4)
+To see the value of a variable, do `\\[describe-variable]' and enter the variable
+name at the prompt.
+
+When entering a key sequence like `C-c C-n', it is not necessary to
+release the CONTROL key after doing the `C-c' part -- it suffices to
+press the CONTROL key, press and release `c' (while still holding down
+CONTROL), press and release `n' (while still holding down CONTROL), &
+then release CONTROL.
+
+Entering Python mode calls with no arguments the value of the variable
+`python-mode-hook', if that value exists and is not nil; for backward
+compatibility it also tries `py-mode-hook'; see the `Hooks' section of
+the Elisp manual for details.
+
+Obscure: When python-mode is first loaded, it looks for all bindings
+to newline-and-indent in the global keymap, and shadows them with
+local bindings to py-newline-and-indent."))
+
+;;; Helper functions
+
+(defvar py-parse-state-re
+ (concat
+ "^[ \t]*\\(if\\|elif\\|else\\|while\\|def\\|class\\)\\>"
+ "\\|"
+ "^[^ #\t\n]"))
+;; returns the parse state at point (see parse-partial-sexp docs)
+(defun py-parse-state ()
+ (save-excursion
+ (let ( (here (point)) )
+ ;; back up to the first preceding line (if any; else start of
+ ;; buffer) that begins with a popular Python keyword, or a non-
+ ;; whitespace and non-comment character. These are good places to
+ ;; start parsing to see whether where we started is at a non-zero
+ ;; nesting level. It may be slow for people who write huge code
+ ;; blocks or huge lists ... tough beans.
+ (re-search-backward py-parse-state-re nil 'move)
+ (beginning-of-line)
+ (parse-partial-sexp (point) here))))
+
+;; if point is at a non-zero nesting level, returns the number of the
+;; character that opens the smallest enclosing unclosed list; else
+;; returns nil.
+(defun py-nesting-level ()
+ (let ( (status (py-parse-state)) )
+ (if (zerop (car status))
+ nil ; not in a nest
+ (car (cdr status))))) ; char# of open bracket
+
+;; t iff preceding line ends with backslash that's not in a comment
+(defun py-backslash-continuation-line-p ()
+ (save-excursion
+ (beginning-of-line)
+ (and
+ ;; use a cheap test first to avoid the regexp if possible
+ ;; use 'eq' because char-after may return nil
+ (eq (char-after (- (point) 2)) ?\\ )
+ ;; make sure; since eq test passed, there is a preceding line
+ (forward-line -1) ; always true -- side effect
+ (looking-at py-continued-re))))
+
+;; t iff current line is a continuation line
+(defun py-continuation-line-p ()
+ (save-excursion
+ (beginning-of-line)
+ (or (py-backslash-continuation-line-p)
+ (py-nesting-level))))
+
+;; go to initial line of current statement; usually this is the
+;; line we're on, but if we're on the 2nd or following lines of a
+;; continuation block, we need to go up to the first line of the block.
+;;
+;; Tricky: We want to avoid quadratic-time behavior for long continued
+;; blocks, whether of the backslash or open-bracket varieties, or a mix
+;; of the two. The following manages to do that in the usual cases.
+(defun py-goto-initial-line ()
+ (let ( open-bracket-pos )
+ (while (py-continuation-line-p)
+ (beginning-of-line)
+ (if (py-backslash-continuation-line-p)
+ (while (py-backslash-continuation-line-p)
+ (forward-line -1))
+ ;; else zip out of nested brackets/braces/parens
+ (while (setq open-bracket-pos (py-nesting-level))
+ (goto-char open-bracket-pos)))))
+ (beginning-of-line))
+
+;; go to point right beyond final line of current statement; usually
+;; this is the start of the next line, but if this is a multi-line
+;; statement we need to skip over the continuation lines.
+;; Tricky: Again we need to be clever to avoid quadratic time behavior.
+(defun py-goto-beyond-final-line ()
+ (forward-line 1)
+ (let ( state )
+ (while (and (py-continuation-line-p)
+ (not (eobp)))
+ ;; skip over the backslash flavor
+ (while (and (py-backslash-continuation-line-p)
+ (not (eobp)))
+ (forward-line 1))
+ ;; if in nest, zip to the end of the nest
+ (setq state (py-parse-state))
+ (if (and (not (zerop (car state)))
+ (not (eobp)))
+ (progn
+ ;; BUG ALERT: I could swear, from reading the docs, that
+ ;; the 3rd argument should be plain 0
+ (parse-partial-sexp (point) (point-max) (- 0 (car state))
+ nil state)
+ (forward-line 1))))))
+
+;; t iff statement opens a block == iff it ends with a colon that's
+;; not in a comment
+;; point should be at the start of a statement
+(defun py-statement-opens-block-p ()
+ (save-excursion
+ (let ( (start (point))
+ (finish (progn (py-goto-beyond-final-line) (1- (point))))
+ (searching t)
+ (answer nil)
+ state)
+ (goto-char start)
+ (while searching
+ ;; look for a colon with nothing after it except whitespace, and
+ ;; maybe a comment
+ (if (re-search-forward ":\\([ \t]\\|\\\\\n\\)*\\(#.*\\)?$"
+ finish t)
+ (if (eq (point) finish) ; note: no `else' clause; just
+ ; keep searching if we're not at
+ ; the end yet
+ ;; sure looks like it opens a block -- but it might
+ ;; be in a comment
+ (progn
+ (setq searching nil) ; search is done either way
+ (setq state (parse-partial-sexp start
+ (match-beginning 0)))
+ (setq answer (not (nth 4 state)))))
+ ;; search failed: couldn't find another interesting colon
+ (setq searching nil)))
+ answer)))
+
+;; go to point right beyond final line of block begun by the current
+;; line. This is the same as where py-goto-beyond-final-line goes
+;; unless we're on colon line, in which case we go to the end of the
+;; block.
+;; assumes point is at bolp
+(defun py-goto-beyond-block ()
+ (if (py-statement-opens-block-p)
+ (py-mark-block nil 'just-move)
+ (py-goto-beyond-final-line)))
+
+;; go to start of first statement (not blank or comment or continuation
+;; line) at or preceding point
+;; returns t if there is one, else nil
+(defun py-goto-statement-at-or-above ()
+ (py-goto-initial-line)
+ (if (looking-at py-blank-or-comment-re)
+ ;; skip back over blank & comment lines
+ ;; note: will skip a blank or comment line that happens to be
+ ;; a continuation line too
+ (if (re-search-backward "^[ \t]*[^ \t#\n]" nil t)
+ (progn (py-goto-initial-line) t)
+ nil)
+ t))
+
+;; go to start of first statement (not blank or comment or continuation
+;; line) following the statement containing point
+;; returns t if there is one, else nil
+(defun py-goto-statement-below ()
+ (beginning-of-line)
+ (let ( (start (point)) )
+ (py-goto-beyond-final-line)
+ (while (and
+ (looking-at py-blank-or-comment-re)
+ (not (eobp)))
+ (forward-line 1))
+ (if (eobp)
+ (progn (goto-char start) nil)
+ t)))
+
+;; go to start of statement, at or preceding point, starting with keyword
+;; KEY. Skips blank lines and non-indenting comments upward first. If
+;; that statement starts with KEY, done, else go back to first enclosing
+;; block starting with KEY.
+;; If successful, leaves point at the start of the KEY line & returns t.
+;; Else leaves point at an undefined place & returns nil.
+(defun py-go-up-tree-to-keyword (key)
+ ;; skip blanks and non-indenting #
+ (py-goto-initial-line)
+ (while (and
+ (looking-at "[ \t]*\\($\\|#[^ \t\n]\\)")
+ (zerop (forward-line -1))) ; go back
+ nil)
+ (py-goto-initial-line)
+ (let* ( (re (concat "[ \t]*" key "\\b"))
+ (case-fold-search nil) ; let* so looking-at sees this
+ (found (looking-at re))
+ (dead nil))
+ (while (not (or found dead))
+ (condition-case nil ; in case no enclosing block
+ (py-goto-block-up 'no-mark)
+ (error (setq dead t)))
+ (or dead (setq found (looking-at re))))
+ (beginning-of-line)
+ found))
+
+;; return string in buffer from start of indentation to end of line;
+;; prefix "..." if leading whitespace was skipped
+(defun py-suck-up-leading-text ()
+ (save-excursion
+ (back-to-indentation)
+ (concat
+ (if (bolp) "" "...")
+ (buffer-substring (point) (progn (end-of-line) (point))))))
+
+;; assuming point at bolp, return first keyword ([a-z]+) on the line,
+;; as a Lisp symbol; return nil if none
+(defun py-suck-up-first-keyword ()
+ (let ( (case-fold-search nil) )
+ (if (looking-at "[ \t]*\\([a-z]+\\)\\b")
+ (intern (buffer-substring (match-beginning 1) (match-end 1)))
+ nil)))
+
+(defun py-make-temp-name ()
+ (make-temp-name
+ (concat (file-name-as-directory py-temp-directory) "python")))
+
+(defun py-delete-file-silently (fname)
+ (condition-case nil
+ (delete-file fname)
+ (error nil)))
+
+(defun py-kill-emacs-hook ()
+ ;; delete our temp files
+ (while py-file-queue
+ (py-delete-file-silently (car py-file-queue))
+ (setq py-file-queue (cdr py-file-queue)))
+ (if (not (or py-this-is-lucid-emacs-p py-this-is-emacs-19-p))
+ ;; run the hook we inherited, if any
+ (and py-inherited-kill-emacs-hook
+ (funcall py-inherited-kill-emacs-hook))))
+
+;; make PROCESS's buffer visible, append STRING to it, and force display;
+;; also make shell-mode believe the user typed this string, so that
+;; kill-output-from-shell and show-output-from-shell work "right"
+(defun py-append-to-process-buffer (process string)
+ (let ( (cbuf (current-buffer))
+ (pbuf (process-buffer process))
+ (py-scroll-process-buffer t))
+ (set-buffer pbuf)
+ (goto-char (point-max))
+ (move-marker (process-mark process) (point))
+ (if (not py-this-is-emacs-19-p)
+ (move-marker last-input-start (point))) ; muck w/ shell-mode
+ (funcall (process-filter process) process string)
+ (if (not py-this-is-emacs-19-p)
+ (move-marker last-input-end (point))) ; muck w/ shell-mode
+ (set-buffer cbuf))
+ (sit-for 0))
+
+;; To do:
+;; - support for ptags
projects / thirdparty / Python / cpython.git / commitdiff
