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Text File | 1994-04-28 | 63.9 KB | 1,662 lines | [TEXT/R*ch] |
- ;;; Major mode for editing Python programs, version 1.09
- ;; 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 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))
-
- (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
- `py-mode-hook', if that value exists and is not nil; 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
-