Property Lists

Every object in the system can have a property list that may be used for information about that object. For example, a function may have a property list that includes information about the source file in which it is defined.

Property lists are implemented as assq lists (see section Association Lists).

Currently, property lists are implemented differently for procedures and closures than for other kinds of objects. Therefore, when manipulating a property list associated with a procedure object, use the procedure functions; otherwise, use the object functions.

primitive: object-properties obj

primitive: procedure-properties obj

Return obj's property list.

primitive: set-object-properties! obj alist

primitive: set-procedure-properties! obj alist

Set obj's property list to alist.

primitive: object-property obj key

primitive: procedure-property obj key

Return the property of obj with name key.

primitive: set-object-property! obj key value

primitive: set-procedure-property! obj key value

In obj's property list, set the property named key to value.

[Interface bug: there should be a second level of interface in which the user provides a "property table" that is possibly private.]

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