As with all compiler switch variables, the value of this variable
can be t, nil, or a
function object that accepts four arguments and returns t or nil. The arguments
passed to the function will be the values of the safety, space, speed,
and debug optimization qualities, in that order. nil is equivalent to a function that always returns
nil and t to a
function that always returns t. When the
value is a function and we say t (or true) or
nil (or false) in the text below, we mean
that the function returns, respectively, t or
nil.
If true, code calling car and cdr
will check that the argument is appropriate (i.e. a cons). The switch
is only effective on platforms which have
:verify-car-cdr on the *features* list. Platforms lacking that feature
ignore this switch since the verification is done differently but
always. Initially true if speed is less than 3 or safety is greater
than 1.
See compiling.htm for information on the compiler.
The documentation is described in introduction.htm and the index is in index.htm.
Copyright (c) 1998-2000, Franz Inc. Berkeley, CA., USA. All rights reserved.
Created 2000.10.5.