Emacs buffer mode histogram
Tonight I noticed that I had over 200 buffers open in emacs. I’ve been programming a lot in Python recently, so many of them are in Python mode. I wondered how many Python files I had open, and I counted them by hand. About 90. I then wondered how many were in Javascript mode, in RST mode, etc. I wondered what a histogram would look like, for me and for others, at times when I’m programming versus working on documentation, etc.
Because it’s emacs, it wasn’t hard to write a function to display a buffer mode histogram. Here’s mine:
235 buffers open, in 23 distinct modes 91 python +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 47 fundamental +++++++++++++++++++++++++++++++++++++++++++++++ 24 js2 ++++++++++++++++++++++++ 21 dired +++++++++++++++++++++ 16 html ++++++++++++++++ 7 text +++++++ 4 help ++++ 4 emacs-lisp ++++ 3 sh +++ 3 makefile-gmake +++ 2 compilation ++ 2 css ++ 1 Buffer-menu + 1 mail + 1 grep + 1 completion-list + 1 vm + 1 org + 1 comint + 1 apropos + 1 Info + 1 vm-summary + 1 vm-presentation +
Tempting as it is, I’m not going to go on about the heady delights of having a fully programmable editor. You either already know, or you can just drool in slack-jawed wonder.
Unfortunately I’m a terrible emacs lisp programmer. I can barely remember a thing each time I use it. But the interpreter is of course just emacs itself and the elisp documentation is in emacs, so it’s a really fun environment to develop in. And because emacs lisp has a ton of support for doing things to itself, code that acts on emacs and your own editing session or buffers is often very succinct. See for example the save-excursion and with-output-to-temp-buffer functions below.
(defun buffer-mode-histogram ()
"Display a histogram of emacs buffer modes."
(interactive)
(let* ((totals '())
(buffers (buffer-list()))
(total-buffers (length buffers))
(ht (make-hash-table :test 'equal)))
(save-excursion
(dolist (buffer buffers)
(set-buffer buffer)
(let
((mode-name (symbol-name major-mode)))
(puthash mode-name (1+ (gethash mode-name ht 0)) ht))))
(maphash (lambda (key value)
(setq totals (cons (list key value) totals)))
ht)
(setq totals (sort totals (lambda (x y) (> (cadr x) (cadr y)))))
(with-output-to-temp-buffer "Buffer mode histogram"
(princ (format "%d buffers open, in %d distinct modes\n\n"
total-buffers (length totals)))
(dolist (item totals)
(let
((key (car item))
(count (cadr item)))
(if (equal (substring key -5) "-mode")
(setq key (substring key 0 -5)))
(princ (format "%2d %20s %s\n" count key
(make-string count ?+))))))))
Various things about the formatting could be improved. E.g., not use fixed-width fields for the count and the mode names, and make the + signs indicate more than one buffer mode when there are many.
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November 11th, 2011 at 4:35 am
Neat idea, saw it on python planet; reminded me that while I’ve hacked in elisp almost-literally forever, python is my language of choice (and greatest ease), and I’d recently decided to start making more use of pymacs, since I always have it around (at least on Debian and Ubuntu boxes), to overcome the friction I find in elisp… cribbing from some older pymacs code of mine and just looking at your output, it took me less time to come up with a pymacs version than it did to write this comment. (Not trying to brag :-) just noting that it really is that frictionless compared to elisp.) To load it, if you have pymacs, just M-: (pymacs-load “mode-stats”) and the m-x mode-stats-mode-stats RET to actually run it.
Assuming disqus doesn’t mangle this, I’m curious if you find it more readable; the lisp “module” basically gives you everything elisp side, and there’s some complexity regarding data being python-side or emacs-side, plus there can be issues regarding shovelling large objects back and forth. But for things where elisp is weirdly limiting, I find it a nice approach…
11 Fundamental ***********
2 Python **
2 Man **
1 Shell *
1 Lisp Interaction *
1 Help *
1 Zephyr *
1 Completion List *
1 Dired by name *
1 Apropos *
#!/usr/bin/python
# (pymacs-load (expand-file-name “~/elisp/mode-stats”))
from Pymacs import lisp
from collections import defaultdict
def mode_stats():
stats = defaultdict(int)
for buf in lisp.buffer_list():
stats[lisp.buffer_local_value(lisp.intern(“mode-name”), buf)] += 1
outbuf = lisp.get_buffer_create(“*mode-stats*”)
lisp.set_buffer(outbuf)
lisp.erase_buffer()
for bufname in sorted(stats, key=lambda x: stats[x], reverse=True):
lisp.insert(“%3d %-15s %sn” % (stats[bufname], bufname, “*” * stats[bufname]))
lisp.goto_char(0)
lisp.switch_to_buffer(outbuf)
interactions = {mode_stats: “”}
November 11th, 2011 at 4:48 am
Wow! That’s fantastic. I didn’t even know pymacs existed :-) Thanks a lot, I’m going to use it on my next little emacs project….
November 11th, 2011 at 4:53 am
Linked in says we have one friend in common: Gumby :-)
November 11th, 2011 at 11:06 am
Quite neat.
Here is my version derived from yours by incrementally using more loop and less setq:
(Apologies in advance for having that sneaky side effect of filling the hash-table in the loop which ostensibly calculates only the number of buffers.)
(defun buffer-mode-histogram ()
“Display a histogram of emacs buffer modes.”
(interactive)
(let* ((ht (make-hash-table :test ‘equal))
(number-of-buffers (loop for buffer being the buffers
for mode-name = (symbol-name (buffer-local-value ‘major-mode buffer))
do (incf (gethash mode-name ht 0))
count 1))
(totals (sort (loop for key being the hash-keys of ht
using (hash-values value)
collect (list key value))
(lambda (x y) (if (eql (second x) (second y))
(string-lessp (first x) (first y))
(> (second x) (second y)))))))
(with-output-to-temp-buffer “Buffer mode histogram”
(princ (format “%d buffers open, in %d distinct modesnn”
number-of-buffers (length totals)))
(loop for (key count) in totals
do (princ (format “%2d %20s %sn”
count
(if (equal (substring key -5) “-mode”)
(substring key 0 -5) key)
(make-string count ?+)))))))
October 13th, 2012 at 12:29 am
Cool. I adapted your code to make a histogram of word frequency instead. The regexp is kind of messed up so it matches punctuation though. I also added a bit of code to limit the number of +s to some limit and scale the rest.
(defun word-histogram-region (posBegin posEnd)
"Display word histogram showing frequency of word occurrence."
(interactive "r")
(message "Counting...")
(let* ((ht (make-hash-table :test 'equal))
(totals '()))
(save-excursion
(goto-char posBegin)
(while (and ( (cadr x) (cadr y)))))
(with-output-to-temp-buffer "Word histogram"
(princ (format "%d different wordsnn"
(length totals)))
(dolist (item totals)
(let
((key (car item))
(count (cadr item))
(maxcount (cadr (car totals))))
(princ (format "%2d %20s %sn" count key
(make-string (/ (* count (min 36 maxcount)) maxcount) ?+))))))))
October 14th, 2012 at 4:35 am
Cool :-) Thanks for sharing!