![]() |
Section 8.1.1.9: |
![]() |
This abstract class defines a state component which is a set of all instantiations of objects of any class sub-typing from this class in addition to the vdm model types used wherever this class name is used. Note that SAME has to be an instantiated class, not an abstract one.
NOTE | See the important note about vdm state in the notes on vdm-sl usage in this specification. |
This abstract class defines the concept of an object of which a copy may be made. It provides the single feature defined below.
This feature provides for the production of an exact copy of the object concerned.
copy | SAME |
Note that in contrast to a pre-condition written in Sather source code, in vdm-sl the type SAME is not an optional type and therefore self must exist, leading to the pre-condition being vacuously true.
This post-condition equality is not the Sather object equality which would imply that self and res were the same object. Vdm-sl equality means equality of value.
This feature returns a new object which has the same contents as self.
![]() |
Language Index | ![]() |
Library Index | ![]() |
Basic Index |
Comments or enquiries should be made to
Keith
Hopper. Page last modified: Tuesday, 23 May 2000. |
![]() |