在SBCL中，读取-评估-打印循环：

In a SBCL read-eval-print-loop:

CL-USER> (in-package "PS")
#<PACKAGE "PARENSCRIPT">

PS> (ps (regex "foobar"))
"/foobar/;"

PS> (in-package "CL-USER")
#<package "COMMON-LISP-USER">

cl-user> (ps:ps (ps:regex "foobar"))
"/foobar/;"

PS：PS 是Parenscript编译器，如宏运算符。

PS:PS is the Parenscript compiler as a macro operator.