lisp 기본함수

xlisp 도움말 발췌

Symbol Functions

set the global value of a symbol

(set <sym> <expr>)

You can also use (setf (symbol-value <sym>) <expr>)

<sym> the symbol being set

<expr> the new value

returns the new value

set the value of a symbol

(setq [<sym> <expr>]...)

fsubr. You can also use (setf <sym> <expr>)

<sym> the symbol being set (quoted)

<expr> the new value

returns the last new value or NIL if no arguments
 

define a function

(defun <sym> <fargs> <expr>...)

define a macro

(defmacro <sym> <fargs> <expr>...)

fsubr

<sym> symbol being defined (quoted)

<fargs> formal argument list (lambda list) (quoted)

<expr> expressions constituting the body of the function (quoted)

returns the function symbol

---

> (defun prt () '(be))                    

prt                                       

> prt                                     

error: unbound variable - prt             

if continued: try evaluating symbol again 

1> (prt)                                  

(be)                                      
 

1> (defun add (a b) (+ a b))             

add                                      

1> ( add 2 4)                            

6                                        

1> add                                   

error: unbound variable - add            

if continued: try evaluating symbol again

2> (add)                                 

error: too few arguments