verify-car-cdr-switch

$Revision: 5.0.2.3 $

Variable

Package: COMPILER

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 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 cl:*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.

See introduction.htm for a general description of the documentation and index.htm for an index.