82 lines
2.3 KiB
Plaintext
82 lines
2.3 KiB
Plaintext
### Objects
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[
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Datatype objects
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Funcon object
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Funcon object-identity
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Funcon object-class-name
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Funcon object-feature-map
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Funcon object-subobject-sequence
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Funcon object-tree
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Funcon object-single-inheritance-feature-map
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]
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Datatype
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objects ::= object(_:atoms, _:identifiers, _:environments, _:objects*)
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/*
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`object( A, C, Env, O*)` is an object:
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* distinguished by an atom `A`,
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* of a class named `C`,
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* with an environment `Env` with the features of the object, and
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* a sequence `O*` of subobjects of the direct superclasses of `C`.
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`object( A, C, Env)` is an object of a base class.
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`object( A, C, Env, O')` is an object of a class with a single superclass.
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With multiple inheritance, subobjects due to repeated inheritance of the
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same class may be shared.
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Implementations of objects generally represent an object as a vector of
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fields, and use pointers and offsets for efficient access to individual
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fields. The representation of objects used in this specification is
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independent of such implementation concerns.
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*/
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Funcon
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object-identity(_:objects) : =>atoms
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Rule
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object-identity
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object(A:atoms, _:identifiers, _:environments, _*:objects*) ~> A
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Funcon
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object-class-name(_:objects) : =>identifiers
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Rule
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object-class-name
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object(_:atoms, C:identifiers, _:environments, _*:objects*) ~> C
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Funcon
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object-feature-map(_:objects) : =>environments
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Rule
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object-feature-map
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object(_:atoms, _:identifiers, Env:environments, _*:objects*) ~> Env
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Funcon
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object-subobject-sequence(_:objects) : =>objects*
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Rule
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object-subobject-sequence
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object(_:atoms, _:identifiers, _:environments, O*:objects*) ~> O*
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Funcon
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object-tree(_:objects) : =>trees(objects)
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/*
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`object-tree O` forms a tree where the branches are the object trees for
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the direct subobjects of `O`.
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*/
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Rule
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object-tree(O:objects)
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~> tree(O,
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interleave-map (
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object-tree given,
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object-subobject-sequence O))
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Funcon
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object-single-inheritance-feature-map(O:objects) : =>environments
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~> map-override left-to-right-map(
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object-feature-map given,
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single-branching-sequence object-tree O)
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/*
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For multiple inheritance, different resolution orders can be specified
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by using difference linearisations of the object tree.
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*/
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