Gnu.Emacs.Lisp编程入门一书示例代码

最近两天看了Gnu.Emacs.Lisp编程入门一书，把书中的代码示例都写了出来，以及书中的练习题，供有需要的同志使用。
注意：分号后面内容是对应函数及表达式的结果。
:-)

;; Chapter 1: 列表处理

; 在Lisp中，数据和程序都以同样的方式表示；也就是说，它们都是由空格分割、
; 由括号括起来的单词、数字或者其他列表的列表。
; 在一个列表中，列表的元素被称为“原子”，不可再被分割为更小的部分。列表
; 中的原子是由空格一一分割的。

; 双引号中的文本，不论是句子还是段落，都是一个单个原子，被称为串string

'(this list includes "text between quotation marks.")
;(this list includes "text between quotation marks.")

; 列表中的空格数量是无关紧要的
; 单引号，被称为一个引用。当单引号位于一个列表之前时，它告诉lisp不要对
; 这个列表做任何操作，而仅仅是按其原样。
; 但是，如果一个列表前没有引号，这个列表中的第一个符号就很特别了：
; 它是一条计算机要执行的命令（在Lisp中，这些命令被称作函数）

(+ 2 2)
;4

'(this is a quoted list)
;(this is a quoted list)

(this is a quoted list)
;Symbol's function definition is void: this

;; Lisp解释器
; Lisp解释器对一个列表求值时它做些了什么：首先，它查看一下在列表前面是
; 否有单引号。如果有，解释器就为我们给出这个列表。如果没有引号，解释器
; 就查看列表的第一个元素，并判断它是否是一个函数定义。如果它确实是一个
; 函数，则解释器执行函数定义中的指令。否则，解释器打印一个错误消息。

(+ 2 (+ 3 3))
;8

; 一个函数参量是函数后面的原子或者列表

kill-ring-max
;60

Chapter 2：求值实践

;; Chapter 2: 求值实践

(buffer-name)
"*scratch*"

(buffer-file-name)
"f:/Misc/elisp.org"

(concat "abc" "def")
"abcdef"

(substring "The quick brown fox jumped." 16 19)
"fox"

(+ 2 fill-column)
72

;; here is a problem
(concat "The " (+ 2 fill-column) " red foxes.")
(+) ;0

(*) ;1

(+ 3) ;3

(* 3) ;3

(+ 3 4 5) ;12

(* 3 4 5) ;60

;(+ 2 'hello)

(message "This message appears in the echo area!")
"This message appears in the echo area!"

(message "The name of this buffer is: %s." (buffer-name))
"The name of this buffer is: elisp.org."

(message "The value of fill-column is %d." fill-column)
"The value of fill-column is 70."

(message "There are %d %s in the office!"
(- fill-column 14) "pink elephants")
"There are 56 pink elephants in the office!"

(message "He saw %d %s"
(- fill-column 34)
(concat "red "
(substring
"The quick brown foxes jumped." 16 21)
" leaping."))
"He saw 36 red foxes leaping."

(set 'flowers '(rose violet daisy buttercup))
flowers ; C-x C-e, aware the echo area->rose violet daisy buttercup
'flowers ; aware the echo area->flowers
(setq carnivores '(lion tiger leopard))

(setq trees '(pine fir oak maple)
herbivorses '(gazelle antelope zebra))

;; create an couner, increment by 1
(setq counter 0)
(setq counter (+ counter 1)) ; press C-x C-e many times, will get many values
counter

;; create an counter, increment by 2
(setq counter1 0)
(setq counter1 (+ counter1 2)) ; press C-x C-e many times, will get many values

(buffer-name) ;"elisp.el" ; only get the filename

(buffer-file-name) ; "f:/Misc/elisp.el" ; get the filename and its path

(current-buffer) ; #<buffer elisp.el>

(other-buffer) ; #<buffer *Buffer List*>

(switch-to-buffer (other-buffer))

(buffer-size) ; 1814

(point)

(point-max)

(point-min)

Chapter 3：如何编写函数定义

;; Chapter 3: 如何编写函数定义

;; 当注册一个函数后，在函数的最后一个括号后，使用"C-x C-e"来使之生效。

; Version 1
;(defun multiply-by-seven (number)
;  "Multiply NUMBER by seven."
;  (* 7 number))

(multiply-by-seven 3) ; 21

; Version 2
(defun multiply-by-seven (number)
"Multiply NUMBER by seven."
(interactive "p")
(message "The result is %d" (* 7 number)))

(multiply-by-seven 3) ; "The result is 21"

(let ((zebra 'stripes)
(tiger 'fierce))
(message "One kind of animal has %s and another is %s."
zebra tiger))

;"One kind of animal has stripes and another is fierce."

(let ((birch 3)
pine
fir
(oak 'some))
(message
"Here are %d variables with %s, %s, and %s value."
birch pine fir oak))

;"Here are 3 variables with nil, nil, and some value."

(if (> 5 4)
(message
"5 is greater than 4!")) ;"5 is greater than 4!"

;; Version 1: type-of-animal
(defun type-of-animal (characteristic)
"Print message in echo area depending on CHARACTERISTIC.
If the CHARACTERISTIC is the symbol 'fierce',
then warn of a tiger."
(if (equal characteristic 'fierce)
(message "It's a tiger!")))
(type-of-animal 'fierce) ; "It's a tiger!"
(type-of-animal 'zebra) ; nil
(if (> 4 5)                              ; if-part
(message "5 is greater than 4!")     ; then-part
(message "4 is not greater than 5!"))  ; else-part

;; Version 2: type-of-animal
(defun type-of-animal (characteristic)   ; Second version
"Print message in echo area depending on CHARACTERISTIC.
If the CHARACTERISTIC is the symbol 'fierce',
then warn of a tiger;
else say it's not fierce."
(if (equal characteristic 'fierce)
(message "It's a tiger!")
(message "It's not fierce!")))
(type-of-animal 'fierce) ;"It's a tiger!"
(type-of-animal 'zebra) ;"It's not fierce!"
(if 4
'true
'false) ;true
(if nil
'true
'false) ;false
(> 5 4) ;t
(> 4 5) ;nil
(let ((foo (buffer-name))
(bar (buffer-size)))
(message
"This buffer is %s and has %d characters."
foo bar)) ;"This buffer is elisp.el and has 3811 characters."
(message "We are %d characters into this buffer."
(- (point)
(save-excursion
(goto-char (point-min)) (point))))

(emacs-version) ;
"GNU Emacs 24.4.1 (x86_64-w64-mingw32) of 2014-10-21 on KAEL"

(substring (emacs-version) 10 12)
;"24"

;; Problem
(if (string= (int-to-string 24）
（substring (emacs-version) 10 12))
(message "This is version 24 Emacs")
(message "This is not version 24 Emacs"))
(defun is-larger-fill-column (number)
"This function"
(if (> number fill-column)
(message "%d is larger than fill-column!" number)
(message "%d is not greater than fill-column!" number)))

;; Exercise 1:
(defun two-times (number)
"multi number by 2"
(message "multi %d by 2 is: %d" number (* 2 number)))
(two-times 2) ;"multi 2 by 2 is: 4"
(two-times 25) ;"multi 25 by 2 is: 50"
(defun two-times (number)
"multi number by 2"
(interactive "p")
(message "multi %d by 2 is: %d" number (* 2 number)))

;; Exercise 2:
(is-larger-fill-column 23) ;"23 is not greater than fill-column!"
(is-larger-fill-column 73) ;"73 is larger than fill-column!"

Chapter 4：与缓冲区有关的函数

;; Chapter 4: 与缓冲区有关的函数

; beginning-of-buffer
(defun simplified-beginning-of-buffer ()
"Move point to the beginning of the buffer;
leave mark at previous position."
(interactive)
(push-mark)
(goto-char (point-min)))

Chapter 5:

;; Chapter 5: 更复杂的函数

Chapter 6:

;; Chapter 6：变窄和增宽

Chapter 7：基本函数：car、cdr、cons

;; Chapter 7: 基本函数：car、cdr、cons
; cons -> construct
; car -> Contents of the Address part of the Register （寄存器地址的部分内容）
; car 返回列表的第一个元素，
; cdr -> Contents of the Decrement part of the Register （寄存器后部内容）
; cdr 返回第一个元素后的所有内容

(car '(rose violet daisy buttercup)) ; output: rose
(cdr '(rose violet daisy buttercup)) ; output: (violet daisy buttercup)

(car '((lion tiger cheetah)
(gazelle antelope zebra)
(whale dolphin seal))) ; output: (lion tiger cheetah)

(cdr '((lion tiger cheetah)
(gazelle antelope zebra)
(whale dolphin seal))) ; output: ((gazelle antelope zebra) (whale dolphin seal))

(cons 'pine '(fir oak maple)) ; output: (pine fir oak maple)

(cons 'buttercup ()) ; (buttercup)

(cons 'daisy '(buttercup)) ; (daisy buttercup)

(cons 'violet '(daisy buttercup)) ; (violet daisy buttercup)

(cons 'rose '(violet daisy buttercup)) ; (rose violet daisy buttercup)

(length '(buttercup)) ; 1

(length '(daisy buttercup)) ; 2

(length (cons 'violet '(daisy buttercup))) ; 3

(length ()) ; 0

(length ) ; (wrong-number-of-arguments length 0)

(cdr '(pine fir oak maple)) ; (fir oak maple)
(cdr '(fir oak maple)) ; (oak maple)
(cdr '(oak maple)) ; (maple)
(cdr '(maple)) ; nil
(cdr 'nil) ; nil
(cdr ()) ; nil
(cdr (cdr '(pine fir oak maple))) ; (oak maple)

(nthcdr 2 '(pine fir oak maple)) ; (oak maple)
(nthcdr 0 '(pine fir oak maple)) ; (pine fir oak maple)
(nthcdr 1 '(pine fir oak maple)) ; (fir oak maple)
(nthcdr 3 '(pine fir oak maple)) ; (maple)
(nthcdr 4 '(pine fir oak maple)) ; nil
(nthcdr 5 '(pine fir oak maple)) ; nil

(setq animals '(giraffe antelope tiger lion))
; (giraffe antelope tiger lion)

animals
; (giraffe antelope tiger lion)

(setcar animals 'hippopotamus)
; hippopotamus

animals
; (hippopotamus antelope tiger lion)

(setq domesticated-animals '(horse cow sheep goat))
; (horse cow sheep goat)

domesticated-animals
; (horse cow sheep goat)

(setcdr domesticated-animals '(cat dog))
; (cat dog)

domesticated-animals
; (horse cat dog)

Chapter 8：剪切和存储文本

;; Chapter 8: 剪切和存储文本

Chapter 9：列表是如何实现的

;; Chapter 9: 列表是如何实现的

(setq bouquet '(rose violet buttercup))
; (rose violet buttercup)

(setq flowers (cdr bouquet))
; (violet buttercup)

(setq bouquet (cons 'lilly bouquet))
bouquet

(eq (cdr (cdr bouquet)) flowers)
;t

(setq flowers '(violet buttercup))
;(violet buttercup)

(setq flowers (cons 'liu flowers))
;(liu violet buttercup)

(setq flowers (cons 'laven flowers))
;(laven liu violet buttercup)

(setq more-flowers flowers)
more-flowers
;(laven liu violet buttercup)

(setq myfish (car flowers))
;laven

more-flowers
;(laven liu violet buttercup)

Chapter 10：找回文本

;; Chapter 10: 找回文本

;; kill-ring环中可以保存多少文本块
kill-ring-max
;60

;; 查看kill-ring环中的第一个元素
(car kill-ring)
;#("(car kill-ring)" 0 15 (fontified t))

(car (nthcdr 0 kill-ring))
(car (nthcdr 1 kill-ring))
(car (nthcdr 2 kill-ring))
(car (nthcdr 3 kill-ring))
(car (nthcdr 4 kill-ring))

Chapter 11：

;; Chapter 11: 循环和递归

(setq animals '(giraffe gazelle lion tiger))
animals

(defun print-elements-of-list (list)
"Print each elements of LIST on a line of its on."
(while list
(print (car list))
(setq list (cdr list))
)
)
(print-elements-of-list animals)
;
;giraffe
;
;gazelle
;
;lion
;
;tiger
;nil

(defun triangle (number-of-rows)
"Add up the number of pebbles in a triangle.
The first row has one pebble, the second row two pebbles,
the third row three pebbles, and so on.
The argument is NUMBER-OF-ROW."
(let ((total 0)
(row-number 1))
(while (<= row-number number-of-rows)
(setq total (+ total row-number))
(setq row-number (1+ row-number)))
total))

(triangle 4)
;10

(triangle 7)
;28

Chapter 12：正则表达式查询

;; Chapter 12: 正则表达式查询

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