Generic Function Lambda Lists

A generic function lambda list is used to describe the overall shape of the argument list to be accepted by a generic function. Individual method signatures might contribute additional keyword parameters to the lambda list of the effective method.

A generic function lambda list is used by defgeneric.

A generic function lambda list has the following syntax:

lambda-list ::=({var}{*} [{&optional {var | (var)}{*}]} [{&rest var]} [{&key {var | ({var | (keyword-name var)}{)}}{*} pt [&allow-other-keys]])}

A generic function lambda list can contain the lambda list keywords shown in Figure 3--14.

&allow-other-keys &optional &key &rest

Figure 3--14: Lambda List Keywords used by Generic Function Lambda Lists

A generic function lambda list differs from an ordinary lambda list in the following ways:

Required arguments

Zero or more required parameters must be specified.

Optional and keyword arguments

Optional parameters and keyword parameters may not have default initial value forms nor use supplied-p parameters.

Use of &aux

The use of &aux is not allowed.

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