2.6 Specialized Arguments to Generic Functions

Unless otherwise stated, this specification uses the following convention for specifying which arguments to generic functions are specialized: [annotate]

• If the generic function is a setf function, the second argument is the one that is intended to be specialized. [annotate]
• If the generic function is a "mapping" function (such as map-over-region-set-regions), the second argument (the object that specifies what is being mapped over) is the one that is specialized. The first argument (the functional argument) is not intended to be specialized. [annotate]
• Otherwise, the first argument is the one that is intended to be specialized. [annotate]