common-lisp LOOP, a Common Lisp macro for iteration Conditionally executing LOOP clauses
Example
LOOP has its own IF statement that can control how the clauses are
executed:
(loop repeat 1000
for x = (random 100)
if (evenp x)
collect x into evens
else
collect x into odds
finally (return (values evens odds)))
Combining multiple clauses in an IF body requires special syntax:
(loop repeat 1000
for x = (random 100)
if (evenp x)
collect x into evens
and do (format t "~a is even!~%" x)
else
collect x into odds
and count t into n-odds
finally (return (values evens odds n-odds)))
