Emacs Lisp基础数据类型

古城微笑少年丶 2022-08-07 18:59 167阅读 0赞

## Table of Contents ##

*  1. List Data Types

# List Data Types #

1.  基本类型有: integer, float, cons, symbol, string, vector, hash-table, subr, byte-code function
2.  字符一般以?开头，如(print ?A) => A
3.  Symbol: lisp object的符号表示，用来表示object的名称 (symbol-name ‘foo) => “foo”
    
     *  symbol按照存储方式分为两类，一类属于系统symbol,存储在bucket obarray中；一类属于编程使用symbol，使用make-symbol创建，在obarray中查找不到。
     *  常用函数
        
        <table>      
         <tbody> 
          <tr> 
           <td>func-name</td> 
           <td>usage</td> 
           <td>desc</td> 
          </tr> 
          <tr> 
           <td>symbol-name</td> 
           <td>(symbol-name ‘foo) =&gt; “foo”</td> 
           <td>获取symbol名称，返回字符串名称</td> 
          </tr> 
          <tr> 
           <td>make-symbol</td> 
           <td>(setq sym (make-symbol “foo”)) =&gt; foo (eq sym ‘foo) =&gt; nil</td> 
           <td>创建非obarray的symbol</td> 
          </tr> 
          <tr> 
           <td>intern</td> 
           <td>(setq sym (intern “foo”)) =&gt; foo (eq sym ‘foo) =&gt; t</td> 
           <td>创建obarray 的symbol</td> 
          </tr> 
          <tr> 
           <td>intern-soft</td> 
           <td>(setq sym (intern “frazzle”)) =&gt; frzzle (intern-soft “frazzle”) =&gt; frazzle</td> 
           <td>测试symbol是否存在</td> 
          </tr> 
          <tr> 
           <td>mapatoms</td> 
           <td>(setq count 0) =&gt; 0 (defun count-sym (s) (setq count (1+ count))) =&gt; count-sym (mapatoms ‘count-syms) =&gt; nil count =&gt; 1871</td> 
           <td>&nbsp;</td> 
          </tr> 
          <tr> 
           <td>unintern</td> 
           <td>&nbsp;</td> 
           <td>delete a symbol in obarray</td> 
          </tr> 
         </tbody> 
        </table>
     *  变量
        
        <table>     
         <tbody> 
          <tr> 
           <td>var-name</td> 
           <td>desc</td> 
          </tr> 
          <tr> 
           <td>obarray</td> 
           <td>it’s a hash-table, used to stored intern symbol</td> 
          </tr> 
         </tbody> 
        </table>
4.  String相关函数
    
    <table>     
     <thead> 
      <tr> 
       <th>func-name</th> 
       <th>desc</th> 
      </tr> 
     </thead> 
     <tbody> 
      <tr> 
       <td>stringp obj</td> 
       <td>check whether object is string type</td> 
      </tr> 
      <tr> 
       <td>string-or-null-p obj</td> 
       <td>ret t if obj is a string or ‘nil’</td> 
      </tr> 
      <tr> 
       <td>char-or-string-p obj</td> 
       <td>ret t if obj is a string or char</td> 
      </tr> 
      <tr> 
       <td>make-string cnt char</td> 
       <td>ret a string made up of COUNT repetitions of CHAR</td> 
      </tr> 
      <tr> 
       <td>string &amp;rest chars</td> 
       <td>ret a string containing the CHARs</td> 
      </tr> 
      <tr> 
       <td>substring string st &amp;opt end</td> 
       <td>(substring “abcdefg” 0 3)=&gt; “abc”</td> 
      </tr> 
      <tr> 
       <td>substring-no-properties str &amp;opt st end</td> 
       <td>like substring but discards all text properties</td> 
      </tr> 
      <tr> 
       <td>concat &amp;rest sequences</td> 
       <td>ret new string containing sequences</td> 
      </tr> 
      <tr> 
       <td>split-string str &amp;opt sep omit-nulls trim</td> 
       <td>splits STRING into substrings</td> 
      </tr> 
      <tr> 
       <td>var: split-string-default-separators</td> 
       <td>split-string default sep</td> 
      </tr> 
     </tbody> 
    </table>
5.  Lists
    
     *  Association Lists  
        关联链表，如: ‘((a . 1)(b . 2))为key, value的键值对，通过相关函数可以做查询，存取操作。  
        ‘(a . 1) 和 ‘(a 1)的区别，’(a . 1)是 a和1组成的，而’(a 1)是a和(1)组成。
        
        1.  相关函数
            
             *  assoc key alist  
                获取第一个匹配key对应的键值对，如:
                
                    (assoc 'a '((a . 1) (b . 2) (a . 3))) => (a . 1)
             *  rassoc value alist  
                获取第一个匹配value值的键值对，如:
                
                    (rassoc '1 '((a . 1)(b . 2)(c . 1))) => (a . 1)
             *  assq key alist  
                和assoc相同，唯一区别使用eq函数进行比较，而assoc使用的equal比较。如：
                
                    (setq leaves '(("simple leaves" . oak)("compound leaves" . horsechestnut)))
                    (assq "simple leaves" leaves) => nil
                    (assoc "simple leaves" leaves) => ("simple leaves" . oak)
             *  rassq value alist  
                同assq对应，使用eq比较函数
             *  assoc-default key alist &opt test default
             *  copy-alist alist  
                拷贝alist, 为取值拷贝，非地址拷贝。如:
                
                    (setcdr (assq 3 copy) '("Martian Vacuum Pine"))
                    (cdr (assq 3 needles-per-cluster))
                     => ("Pitch Pine")
             *  assq-delete-all key alist  
                返回删除alist所有匹配key取值的键值对，这个函数会破坏入参alist。  
                如:
                
                    (setq alist '((foo 1) (bar 2) (foo 3) (lose 4)))
                    => ((foo 1) (bar 2) (foo 3) (lose 4))
                    (assq-delete-all 'foo alist)
                    => ((bar 2) (lose 4))
                    alist
                    => ((foo 1) (bar 2) (lose 4))
             *  rassq-delete-all value alist