Next: Defining Your Own Packages, Previous: Syntax of Names, Up: Common Lisp Package System [Contents][Index]
When you first start Lisp, the value of ‘*PACKAGE*’ is typically the ‘COMMON-LISP-USER’ package, also known as ‘CL-USER’. ‘CL=USER’ uses the package ‘COMMON-LISP’, which exports all the names defined by the language standard.
When you type an expression at the ‘REPL’, all the names of standard functions, macros, variables, and so on will be translated to the symbols exported from ‘COMMON-LISP’, and all other names will be interned in the ‘COMMON-LISP-USER’ package.
The ‘REPL’ cannot start in the ‘COMMON-LISP’ package because you are not allowed to intern new symbols in it; ‘COMMON-LISP-USER’ serves as a "scratch" package where you can create your own names while still having easy access to all the symbols in ‘COMMON-LISP’.
The third standard package is the ‘KEYWORD’ package, the package the Lisp reader uses to intern names starting with a colon.