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elisp.html.markdown: Bump to v0.2.

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Bastien Guerry
2013-07-26 11:59:51 +02:00
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@@ -2,11 +2,11 @@
language: elisp language: elisp
contributors: contributors:
- ["Bastien Guerry", "http://bzg.fr"] - ["Bastien Guerry", "http://bzg.fr"]
filename: elisp.el filename: learn-emacs-lisp.el
--- ---
```elisp ```elisp
;; This gives an introduction to Emacs Lisp in 15 minutes. ;; This gives an introduction to Emacs Lisp in 15 minutes (v0.2)
;; ;;
;; First make sure you read this text by Peter Norvig: ;; First make sure you read this text by Peter Norvig:
;; http://norvig.com/21-days.html ;; http://norvig.com/21-days.html
@@ -19,10 +19,20 @@ filename: elisp.el
;; ;;
;; More general information can be found at: ;; More general information can be found at:
;; http://www.gnu.org/software/emacs/#Obtaining ;; http://www.gnu.org/software/emacs/#Obtaining
;; Important warning:
;;
;; Going through this tutorial won't damage your computer unless
;; you get so angry that you throw it on the floor. In that case,
;; I hereby decline any responsability. Have fun!
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Fire up Emacs. ;; Fire up Emacs.
;; ;;
;; Look at the gray line at the bottom of the window: ;; Hit the `q' key to dismiss the welcome message.
;;
;; Now look at the gray line at the bottom of the window:
;; ;;
;; "*scratch*" is the name of the editing space you are now in. ;; "*scratch*" is the name of the editing space you are now in.
;: This editing space is called a "buffer". ;: This editing space is called a "buffer".
@@ -33,12 +43,14 @@ filename: elisp.el
;; ;;
;; "Lisp interaction" refers to a set of commands available here. ;; "Lisp interaction" refers to a set of commands available here.
;; ;;
;; This set of command is loaded on top of core Emacs commands. ;; Emacs has a built-in set of commands available in every buffer,
;; For exemple, `save-buffer' is a core Emacs command to save a ;; and several subsets of commands available when you activate a
;; buffer to its associated file, and `eval-defun' is a command ;; specific mode. Here we use the `lisp-interaction-mode', which
;; loaded from the `lisp-interaction-mode' you are now in. ;; comes with commands to evaluate and navigate within Elisp code.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Semi-columns start comments anywhere on a line. ;; Semi-colons start comments anywhere on a line.
;; ;;
;; Elisp programs are made of symbolic expressions ("sexps"): ;; Elisp programs are made of symbolic expressions ("sexps"):
(+ 2 2) (+ 2 2)
@@ -54,7 +66,7 @@ filename: elisp.el
;; From `lisp-interaction-mode' you can evaluate sexps. ;; From `lisp-interaction-mode' you can evaluate sexps.
;; Put the cursor right after the closing parenthesis then ;; Put the cursor right after the closing parenthesis then
;; hit the control and the j keys ("C-j" for short). ;; hold down the control and hit the j keys ("C-j" for short).
(+ 3 (+ 1 2)) (+ 3 (+ 1 2))
;; ^ cursor here ;; ^ cursor here
@@ -109,13 +121,17 @@ filename: elisp.el
;; Take a breath. ;; Take a breath.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Now switch to a new buffer named "*test*" in another window: ;; Now switch to a new buffer named "*test*" in another window:
(switch-to-buffer-other-window "*test*") (switch-to-buffer-other-window "*test*")
;; `C-xC-e' ;; `C-xC-e'
;: => [screen has two windows and cursor is in the *test* buffer] ;: => [screen has two windows and cursor is in the *test* buffer]
;; Use the mouse to go back to the window where you code. ;; Mouse over the top window and left-click to go back. Or you can
;; use `C-xo' (i.e. hold down control-x and hit j) to go to the other
;; window interactively.
;; You can combine several sexps with `progn': ;; You can combine several sexps with `progn':
(progn (progn
@@ -127,11 +143,13 @@ filename: elisp.el
;; Now if you don't mind, I'll stop asking you to hit `C-xC-e': do it ;; Now if you don't mind, I'll stop asking you to hit `C-xC-e': do it
;; for every sexp that follows. ;; for every sexp that follows.
;; Always go back to the *scratch* buffer with the mouse or `C-xo'.
;; It's often useful to erase the buffer: ;; It's often useful to erase the buffer:
(progn (progn
(switch-to-buffer-other-window "*test*") (switch-to-buffer-other-window "*test*")
(erase-buffer) (erase-buffer)
(hello "you")) (hello "there"))
;; Or to go back to the other window: ;; Or to go back to the other window:
(progn (progn
@@ -166,9 +184,9 @@ filename: elisp.el
(defun greeting (name) (defun greeting (name)
(let ((your-name "Bastien")) (let ((your-name "Bastien"))
(insert (format "Hello %s!\n\nI'am %s." (insert (format "Hello %s!\n\nI'am %s."
name ; the argument of the function name ; the argument of the function
your-name ; the let-bound variable "Roger" your-name ; the let-bound variable "Bastien"
)))) ))))
;; And evaluate it: ;; And evaluate it:
(greeting "you") (greeting "you")
@@ -182,9 +200,9 @@ filename: elisp.el
(defun greeting (from-name) (defun greeting (from-name)
(let ((your-name (read-from-minibuffer "Enter your name: "))) (let ((your-name (read-from-minibuffer "Enter your name: ")))
(insert (format "Hello!\n\I am %s and you are %s." (insert (format "Hello!\n\I am %s and you are %s."
from-name ; the argument of the function from-name ; the argument of the function
your-name ; the let-bound var, entered at prompt your-name ; the let-bound var, entered at prompt
)))) ))))
(greeting "Bastien") (greeting "Bastien")
@@ -201,8 +219,10 @@ filename: elisp.el
;; Take a breath. ;; Take a breath.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Let's store a list of names: ;; Let's store a list of names:
(setq list-of-names '("Sarah" "Chloe")) (setq list-of-names '("Sarah" "Chloe" "Mathilde"))
;; Get the first element of this list with `car': ;; Get the first element of this list with `car':
(car list-of-names) (car list-of-names)
@@ -214,6 +234,8 @@ filename: elisp.el
(push "Stephanie" list-of-names) (push "Stephanie" list-of-names)
;; NOTE: `car' and `cdr' don't modify the list, but `push' does. ;; NOTE: `car' and `cdr' don't modify the list, but `push' does.
;; This is an important difference: some functions don't have any
;; side-effects (like `car') while others have (like `push').
;; Let's call `hello' for each element in `list-of-names': ;; Let's call `hello' for each element in `list-of-names':
(mapcar 'hello list-of-names) (mapcar 'hello list-of-names)
@@ -283,8 +305,8 @@ filename: elisp.el
(goto-char (point-min)) (goto-char (point-min))
(while (re-search-forward "Bonjour \\(.+\\)!" nil t) (while (re-search-forward "Bonjour \\(.+\\)!" nil t)
(add-text-properties (match-beginning 1) (add-text-properties (match-beginning 1)
(match-end 1) (match-end 1)
(list 'face 'bold))) (list 'face 'bold)))
(other-window 1)) (other-window 1))
;; This functions introduces `re-search-forward': instead of ;; This functions introduces `re-search-forward': instead of
@@ -306,4 +328,21 @@ filename: elisp.el
;; OK, we are done. Happy hacking! ;; OK, we are done. Happy hacking!
;; If you want to know more about a variable or a function:
;;
;; C-h v a-variable RET
;; C-h f a-function RET
;;
;; To read the Emacs Lisp manual with Emacs:
;;
;; C-h i m elisp RET
;;
;; To read an online introduction to Emacs Lisp:
;; https://www.gnu.org/software/emacs/manual/html_node/eintr/index.html
;; Thanks to these people for their feedback and suggestions:
;; - Wes Hardaker
;; - notbob
;; - Kevin Montuori
;; - Arne Babenhauserheide
``` ```