Sagittarius Users' Reference

(clos user) -CLOS user APIs

User level CLOS API collection library.

Macro define-class name supers slots . options

Name must be symbol or identifier.

Supers must be list of class.

Slots must be following structure:

_slots_ ::= (_slot_ ...)
_slot_  ::= (_slot-name_ _specifiers_*)
_specifiers_ ::= `:init-keyword` _keyword_ 
		 | `:init-value` _value_                 | `:init-form` _form_                 | `:reader` _reader-function_                 | `:writer` _writer-function_

Defines a new class.

Slot specifiers:

:init-keyword

This keyword specifies initialisation keyword argument used by the make procedure. Following code describes how to use:

(make <a-class> :slot-a 'slot-a-value)

<a-class> has a slot which slot definition contains the keyword :init-keyword with the keyword :slot-a. The code initialises an instance of the slot with given value slot-a-value.

:init-value

This keyword specifies an initial value of target slot.

:init-form

Similar with :init-keyword but this keyword takes expression which will be evaluated at initialiation time.

:reader

This keyword creates a procedure takes 1 argument an instance of the class to access the slot, so users can read the slot without using slot-ref procedure.

:writer

This keyword creates a procedure takes 2 argument an instance of the class and object to set the slot value with given object, so users can set the slot without using slot-set! procedure.

opttions can specify the metaclass of this class with keyword :metaclass.

NOTE: Current implementation does not support :allocation keyword by default. If you need it, see (sagittarius mop allocation).

Macro define-generic name

Name must be symbol.

Creates a new generic function.

Macro define-method name specifiers body ...

Name must be symbol.

Specifiers must be following structure:

_specifiers_ ::= (_spec_ ... _rest_)
_spec_ ::= (_argument-name_ _class_) | (_argument-name_)
_rest_ ::= '() | symbol

Adds defined method to name generic. If the generic does not exist, this will create a new generic function implicitly.

Function slot-ref obj slot-name

Returns the slot value specified slot-name.

Function slot-set! obj slot-name value

Sets the slot value value with specified slot-name.

Function slot-bound? obj slot-name

Returns #t if the slot value specified slot-name is bounded, otherwise #f.

Generic make class args ...

Creates a new instance of class

Function is-a? object class

Returns #t if object is an instance of class, otherwise #f.

Function subtype? class1 class2

Returns #t if class1 is a subclass of class2, otherwise #f.

Function slot-ref-using-accessor object accessor

This procedure is for MOP.

Returns the slot value got by accessor.

Function slot-set-using-accessor! object accessor value

This procedure is for MOP.

Sets the slot value value to object using accessor.

Function slot-ref-using-class class object slot-name

This procedure is for MOP.

Returns the slot value according to the given class.

It is an error if the given slot-name doesn't exist in the class.

Function slot-set-using-accessor! class object slot-name value

This procedure is for MOP.

Sets the slot value value to object accoring to the given class.

It is an error if the given slot-name doesn't exist in the class.

Function slot-bound-using-class? class object slot-name

This procedure is for MOP.

Returns #t if the slot is bounded according to the given class, otherwise #f.

It is an error if the given slot-name doesn't exist in the class.

Generic write-object object (out )

This method will be called when writing the given object.

Defines how user defined class should be written.

Generic object-equal? object1 object2

This method will be called when equal? is called.

Defines how user defined class should be compared.