zl:1 - FTP

613
warn
Example:
(setq to-string
(array-push-portion-extend
to-string from-string (or from B) to»
If the optional arguments are not provided, the default is to copy all of
from-array to the end of to-array.
warn optional-options optional-condition-name format-string &rest Function
format-args
If the flag *break-on-warnings* is nil, warn prints a warning message
without entering the Debugger. .
If the flag, *break-on-warnings* is not nil, warn enters the Debugger and
prints the warning message. If you continue from the error, warn returns
args.
The optional arguments optional-options and optional-condition-name can be
omitted. They represent more advanced features of warn, the documentation
of which is being deferred.
format-string is an error message string.
format-args are additional arguments; these are evaluated only if a condition
is signalled.
Examples:
(defun sum-numbers (list-of-numbers)
(when « (length list-of-numbers) 2)
(warn ·You are trying to only add -0 number-:P.­
(length list-of-numbers»)
(reduce #'+ list-of-numbers» => SUM-NUMBERS
(sum-numbers '(1»
=> Warning: You are trying to only add 1 number.
(setq *break-on-warnings* t) => T
(sum-numbers '(1»=>
Warning: You are trying to only add 1 number
I