paredit preso

Bay Area Clojure Meetupfunctional lispers

December 3, 2009Runa Galactic Headquarters

Friday, December 4, 2009

pareditAt first it sucks, but then it’s awesome.

mudphone (kyle oba)irc / twitter / github

runa employee 9


about runa

We are simultaneously the largest cloud-based manufacturer, distributor, and consumer of Bavarian-style pretzels, nationally.

http://www.flickr.com/photos/bellalago/3938498023/Friday, December 4, 2009

http://www.flickr.com/photos/bellalago/3938498023/


and we’re hiring

clojure-hbase-ruby-hadoop-rails-javascript-chefs


0/8 why


Q: What is paredit?

A: paredit is a minor mode for Emacs,

created by Taylor R. Campbell.


So, why paredit?

commit 2ecf00a124062d7b4c4538f79426bc19c6b11b83Author: Philip (flip) Kromer <[email protected]>Date: Mon Aug 24 23:38:14 2009 -0500

Paredit fucking sucks my balls


mailto:[email protected]

mailto:[email protected]

Because, these are your father’s parentheses...

http://xkcd.com/297/




Hingebjerg – 2009-06-01T14:05:40ZHi Phil,

Just installed the emacs-starter-kit and clojure-mode, and i can't delete curly braces when in clojure-mode. Is there a logical explanation for that?

Phil – 2009-06-12T09:37:15ZHingebjerg: That's a feature of paredit-mode; it enforces that you can't delete parens (or other matched chars) unless they're empty so you don't end up with invalid structure in your code. It's unbelievably handy/addictive once you get used to it, but if you're not sure what's going on it can be pretty annoying.

http://technomancy.us/126


http://technomancy.us/

http://technomancy.us/



0/8 why1/8 balancing2/8 basic insertion commands3/8 deleting & killing4/8 movement & navigation5/8 depth-changing commands6/8 barfage & slurpage7/8 miscellaneous commands8/8 in the wild (tips & tricks)


1/8 balancing


balancing basics

([“”])

keys

([“


1.1/8 assumptions


you’re using the emacs starter kit

or, you’re already familiar setting the modes up

you’ve got paredit and show-parens modes

M-x paredit-mode

M-x show-paren-mode


install?

;;; Install paredit by placing `paredit.el' in `/path/to/elisp', a;;; directory of your choice, and adding to your .emacs file:;;;;;; (add-to-list 'load-path "/path/to/elisp");;; (autoload 'paredit-mode "paredit";;; "Minor mode for pseudo-structurally editing Lisp code.";;; t);;;;;; Toggle Paredit Mode with `M-x paredit-mode RET', or enable it;;; always in a major mode `M' (e.g., `lisp' or `scheme') with:;;;;;; (add-hook M-mode-hook (lambda () (paredit-mode +1)))

http://mumble.net/~campbell/emacs/paredit.el




1.2/8 demo

wrapping

killing

raising

splicing

slurping / barfing

splitting / joining


2/8 basic insertion commands


paredit-open-round

(a b |c d)

(a b (|) c d)

keys

(


paredit-close-round-and-newline

(a b |c )

(a b c)|

keys

)


paredit-close-round

(a b |c )

(a b c)|

keys

M-)


paredit-open-square

(a b |c d)

(a b [|] c)

keys

[


paredit-close-square

(defn cky [bcn| ] 2)

(defn cky [bcn]| 2)

keys

]


paredit-doublequote

(ça va |bien)

(ça va “|” bien)

keys

“


paredit-doublequote

(while in a quote)

(the “q|uick” fox)

(the “q\”|uick” fox)

keys

“


paredit-meta-doublequote

(the |(cky) bcn)

(the “|(cky)” bcn)

keys

M-”


paredit-meta-doublequote

(while in quote)

(the “chk|y” bcn)

(the “chky” |bcn)

keys

M-”


paredit-comment-dwim

(blah |xyz) ; baz

(blah xyz) ; |baz

keys

M-;



(amit siva)|

(amit siva) ; |

keys

M-;



(hbase)|(clojure)

(hbase);;; |(clojure)

keys

M-;



(ruby) |(java)

(ruby);;; |(java)

keys

M-;


paredit-newline

(let [x 2] |(list x y)

(let [x 2] |(list x y))

keys

C-j


intermission





3/8 deleting & killing


paredit-forward-delete

(|”third” worst)

(“|third” worst)keys

C-d(“|hird” worst)


paredit-forward-delete

(w |(x) y)

(w (|x) y)keys

C-d (w (|) y)

(w | y)


paredit-backward-delete

(w (x)| y)

(w (x|) y)keys

DEL (w (|) y)

(w | y)


paredit-kill

(zee)| ;comment

(zee)|

keys

C-k


paredit-kill

(|zee) ;comment

(|) ;commentkeys

C-k(println “|x is:” x)

(println “|” x)Friday, December 4, 2009

paredit-forward-kill-word

|(declare x) ;commentkeys

M-d(| x) ;comment

(|) ;comment

() ;|


paredit-forward-kill-word

;| hack(declare x)

keys

M-d;|(declare x)

;(| x)


paredit-backward-kill-word

(declare x) ;comment(zee) |

keys

M-DEL (declare x) ;comment(|)

(declare x) ;|Friday, December 4, 2009

paredit-backward-kill-word

keys

M-DEL

(declare x) ;|

(declare |)

(|)


4/8 movement & navigation


paredit-forward

keys

C-M-f(conj |[1 2 3] 4)

(conj [1 2 3]| 4)


paredit-forward

keys

C-M-f

(conj [1 2 3] |4)

(conj [1 2 3] 4|)

(conj [1 2 3] 4)|


paredit-backward

keys

C-M-b(conj [1 2 3]| 4)

(conj |[1 2 3] 4)


paredit-backward

keys

C-M-b

(conj| [1 2 3] 4)

(|conj [1 2 3] 4)

|(conj [1 2 3] 4)


intermission

http://www.flickr.com/photos/nickporjr/2158780350/




5/8 depth-changing commands


paredit-wrap-around

keys

M-((eat |cky bcn)

(eat (|cky) bcn)

same for {}, [], and “”


paredit-splice-sexp

keys

M-s(eat (|cky bcn) sdwch)

(eat |cky bcn sdwch)


paredit-splice-sexp-killing-backward

keys

M-<up>(eat (cky |bcn))

(eat |bcn)


paredit-splice-sexp-killing-forward

keys

M-<down>(eat (cky |bcn))

(eat cky|)


paredit-raise-sexp

keys

M-r

(eat (cky |bcn) sdwch)

(eat |bcn sdwch)

|bcn


6/8 barfage & slurpage


paredit-forward-slurp-sexp

keys

C-)C-<right>

(eat (|cky) bcn z)

(eat (|cky bcn) z)


paredit-forward-barf-sexp

keys

C-}C-<left>

(eat (|cky bcn) z)

(eat (|cky) bcn z)


paredit-backward-slurp-sexp

keys

C-(C-M-<left>

(omg eat (|cky) bcn)

(omg (eat |cky) bcn)


paredit-backward-barf-sexp

keys

C-{C-M-<right>

(omg (eat |cky) bcn)

(omg eat (|cky) bcn)


7/8 miscellaneous commands


paredit-split-sexp

keys

M-S-s(cky |bcn)

(cky) |(bcn)



paredit-join-sexps

keys

M-S-j


(cky)| (bcn)

(cky| bcn)

chunky-| bacon

chunky-|bacon


intermission


8/8 in the wild(tips and tricks)


8.1/8 demo

C-w is not a paredit thing

show-paren-mode warning

fixing unbalanced parens


add parens when unbalanced

(override matched keys w/ C-q)

(important )|

keys

C-q )(important |



remove pesky spaces

(important|)

(important |)

keys

C-k then

<del>

(important| )


remove stray parens

with comments

poor paren|)keys

DELthen ; then

C-d

poor paren)|

poor paren;|)

poor paren;|


override paredit delete

LTR

keys

C-u DELC-u C-dC-u C-k


remove stray parens

probably the right way

poor paren|

keys

C-u DELpoor paren)|


dammit, emacs

keys

M-x butterfly LTR


M-x butterflyhttp://xkcd.com/378/


http://www.emacswiki.org/emacs/PareditCheatsheet


add paredit to the SLIME REPL

;; enable paredit in slime repl(add-hook 'slime-repl-mode-hook (lambda () (paredit-mode +1)))

Karol Skocik - http://coding.derkeiler.com/Archive/Lisp/comp.lang.lisp/2007-07/




customize

;;; Customize paredit using `eval-after-load':;;;;;; (eval-after-load 'paredit;;; '(progn ...redefine keys, &c....));;;;;; ... Now `)' is bound to a;;; command that does not insert a newline, and `M-)' is bound to the;;; command that inserts a newline. To revert to the former behaviour,;;; add the following forms to an `eval-after-load' form for paredit.el;;; in your .emacs file:;;;;;; (define-key paredit-mode-map (kbd ")");;; 'paredit-close-round-and-newline);;; (define-key paredit-mode-map (kbd "M-)");;; 'paredit-close-round)

http://mumble.net/~campbell/emacs/paredit.el




http://www.emacswiki.org/emacs/PareditCheatsheetFriday, December 4, 2009



stole from...

๏ http://mumble.net/~campbell/emacs/paredit.html

๏ http://p.hagelb.org/paredit-screencast.html

technomancy - screencast soon?




http://p.hagelb.org/paredit-screencast.html

http://p.hagelb.org/paredit-screencast.html

consume these...

๏ http://www.emacswiki.org/emacs/ParEdit

๏ http://steve.yegge.googlepages.com/effective-emacs

๏ Peepcode: Meet Emacs๏ http://peepcode.com/products/meet-emacs

๏ Peepcode: Functional Programming with Clojure ๏ http://peepcode.com/products/functional-programming-with-clojure


http://www.emacswiki.org/emacs/ParEdit

http://www.emacswiki.org/emacs/ParEdit

http://mumble.net/~campbell/emacs/paredit.html




http://peepcode.com/products/meet-emacs

http://peepcode.com/products/meet-emacs

images and food...๏ Pretzels - http://www.flickr.com/photos/bellalago/3938498023/

๏ XKCD “Lisp Cycles” - http://xkcd.com/297/

๏ XKCD “Lisp” - http://xkcd.com/224/

๏ XKCD “Real Programmers” - http://xkcd.com/378/

๏ Obligatory LOLCAT - http://www.flickr.com/photos/nickporjr/2158780350/

๏ http://www.emacswiki.org/emacs/PareditCheatsheet

๏ thanks to runa, for the food

http://bitterfilms.shop.musictoday.com/Product.aspx?pc=8BCT06#


















paredit preso

Technology

feature of paredit

paredit fucking

pareditnewlinekeyslet

modesmx pareditmodem

pareditbackwardkeys

t toggle paredit mode

ddeclare x x

modehook lambda pareditmode