The less-familiar parts of Lisp for beginners — define-symbol-macro

Another feature of Lisp that the newcomer might not have encountered is define-symbol-macro.  Think of this as something very close to a C/C++ macro.  It is a way to define a symbol that will be expanded at compile time.  Where the more familiar Lisp macros have a function-like syntax, this creates a macro with a symbol-like syntax, so it is called without surrounding parentheses.

Here’s a short bit of code to demonstrate this:

(define-symbol-macro now (get-time-of-day))
(define-symbol-macro first-fred (car fred))

(defun demonstrate ()
  (format t "The value of symbol 'now' is: ~A~%" now)
  (let ((fred (list 1 2 3 4 5)))
    (format t "The value of symbol 'first-fred' is ~A~%" 
    (let ((fred (list :A :B :C :D :E)))
      (format t "The value of symbol 'first-fred' is ~A~%" 

With output:
CL-USER> (demonstrate)
The value of symbol 'now' is: 1388450944
The value of symbol 'first-fred' is 1
The value of symbol 'first-fred' is A
CL-USER> (macroexpand 'now)
CL-USER> (macroexpand 'first-fred)

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