common lisp 路径 PATHNAME

gistfile1.txt

语法
  merge-pathnames pathname &optional default-pathname default-version
  make-pathname &key host device directory name type version defaults case
	pathname-directory pathname &key case => directory

参数和值
  pathname --- 路径名
  default-pathname --- 默认的pathname, 是 *default-pathname-defaults* 的值(这个值一般是运行路径)
  default-version --- pathname 的 version, 默认是 :newest
	pathname-directory --- 获取 pathname 的目录路径

描述
  merge-pathnames 这个函数根据现有的pathname的传入的 pathname 生成新的pathname
  make-pathname 生成一个 pathname

code
  * *default-pathname-defaults*
  #P"/Users/zhouqiang/workspace/"

  * (merge-pathnames "a")
  #P"/Users/zhouqiang/workspace/a"

  * (merge-pathnames "/Users/zh/wo")
  #P"/Users/zh/wo"
  
  * (make-pathname :directory "/x"
	    :name "y"
	    :type "z")
  #P"//x/y.z"
  
  * (pathname-directory "/a/b/c")
	(:ABSOLUTE "a" "b")

	* (pathname-directory "a/b/c")
	(:RELATIVE "a" "b")
  
TODO
  merge-pathname 的结果有点诡异, 需要详细理解一下