Useful Lisp

• (every function list)
  True if the function is true for every element of list.
  (every #'numberp '(1 23 7)) = T
• (some function list)
  True if the function is true (non-NIL) for some element of list; returns the first non-NIL value.
  (some #'(lambda (x) (if (numberp x) x)) '(a b 3 c 7)) = 3
• (subset function list)         (defined in the file macros.lsp)
  Returns the subset of list for which function is true (non-NIL).
  (subset #'numberp '(a b 3 c 7)) = (3 7)
• (mapcar function list)
  Applies function to each element of list; returns a list of the results.
  (mapcar #'(lambda (x) (+ x 2)) '(1 2 3)) = (3 4 5)
• (mapc function list)
  Like mapcar, but does not make a list of results.
  (mapc #'(lambda (x) (if (> x 3) (print x))) '(2 4 6))
• (mapcan function list)
  Applies function to each element of list; returns a concatenated list of the results (each of which should be a list).
  (mapcan #'(lambda (x) (if (evenp x) (list x))) '(1 2 3 4)) = (2 4)
• (intersection list₁ list₂)
  Set intersection. Also defined are union and set-difference.
  (intersection '(a b c) '(a c e)) = (C A)
• (subst x y z)
  Substitute x for y in z.
  (subst 'sugar 'cream '(peaches and cream)) = (PEACHES AND SUGAR)
• (sublis alist z)
  Substitute from the alist (a list of pairs, (old . new)) in z.
  (sublis '((rose . peach) (smell . taste))
          '(a rose by any other name would smell as sweet))
      = (A PEACH BY ANY OTHER NAME WOULD TASTE AS SWEET)
• (eval code)
  Evaluate (execute) code.
  (eval (subst 5 'r '(* pi (expt r 2)))) = 78.5398
• (apply function args)
  Apply (call) the function on arguments args.
  (apply #'+ '(2 3)) = 5
• (funcall function arg₁ ... arg_n)
  Call the function on arguments arg₁ ... arg_n.
  (funcall (get (car form) 'derivfn) form var)
• (get symbol property)
  Get the value of property for the symbol; if no such property is defined, the result is NIL.
  (get person 'age)
• (setf (get symbol property) value)
  Define the property of symbol to be value.
  (setf (get 'john 'age) 27)