Syntropy Type view Object diagrams/mechanisms Statecharts Logic Value types Glossary

Syntropy Glossary

This glossary defines terms used in the Syntropy method.
Abstract type
An object type such that all objects conforming to it must also conform to one of its sub-types
Active object
An object with its own thread of control
Aggregation
A property of an association representing life-time containment. The life-times of the aggregated objects are contained within the life-time of the aggregating object
Association
A generic description of a related set of links between objects of two types
Association property
A property that belongs to an association rather than an object type
Class
A template defining the implementation of a set of object features
Concept domain
A domain within a specification or implementation model that contains object types corresponding directly to object types found in the essential model
Conformance
When features offered by an object satisfy all the expectations defined by an object type
Consequence
A textual statement of the effects of an event or message on an object
Constraint
A restriction, typically on an association
Creation operation
An operation implicitly invoked on object creation that initialises an object
Derived association
An association whose members can be determined from one or more other associations
Detected event
An event that causes the state of the software system to change
Domain
A collection of related object types that together provide a coherent unit. The domains partition the object types
Encapsulation
Localisation of knowledge within an object
Essential model
A model constructed to describe the structure and behaviour of a real or imagined situation in the world, without reference to the role software might play in its creation
Event
An occurrence that carries information. Events are defined as an instantaneous broadcast of information to all interested objects
Event list
A list in the textual part of a specification or implementation model statechart that indicates all the event types of interest to that object type
Event table
A table listing events, parameters, pre-conditions and consequences
Event type
The signature of an event: its name and parameter types
Exception
An indication in software that a fault has occurred
Exclusive contract
A contract between two objects such that one is the only client of the other
Filter
A statically determinable logical predicate in an event list that defines the set of objects interested in any particular event occurrence
Finalisation
The transition of an object into a condition where it is no longer part of the model
Generated event
An event in a specification model generated by an object
Guard
A logical predicate that limits the availability of a transition in a statechart
Implementation model
A model of a domain constructed to describe the interfaces of objects, their relationships and their interaction (in terms of message sequences)
Infrastructure domain
A domain that provides software-related services to other domains
Inheritance
The ability of a sub-type automatically to include features of its super-types
Initial object
The object that forms the root of an instance of a model; the single instance of the initial type
Initial object configuration
The set of objects, including the initial object, that exist at the moment an instance of a model is created
Initial type
The type of the initial object
Interaction domain
A domain containing types describing objects that connect objects in concept domains to the environment
Internal event
An event in a specification model that is both generated and detected
Invariant
A logical predicate that limits properties or associations
Link
A connection between two objects, in accordance with an association; an instance of an association
Link type
An object type that is related to an association
Mechanism
An example object interaction with messages
Message
A synchronous request made by one object of another, taking a measurable time to process
Message sequence diagram
A diagram that shows a mechanism as a time-line
Model
A description of the structure and behaviour of a set of objects, portrayed through a number of views, built to illustrate a particular perspective: essential, specification or implementation
Multiple association
An association end that yields a set of objects
Multiplicity
The number of objects permitted to form the result of navigating an association
Name space
The set of names that belong to a type, especially its property names and role names
Navigation expression
An expression that traverses associations to yield one or more objects or values, starting from a particular object
nil
The value yielded by unset properties or an empty optional association
Non-exclusive contract
A contract between two objects such that one is just one of many clients of the other
Object
A unique grouping of information that conforms to one or more object types
Object diagram
A diagram depicting objects and their links
Object type
A named set of features to be provided by one or more objects
Observer
An operation that will not cause a change in state of the system
Operation
A named unit of processing belonging to an object type in an implementation model, invoked by a message
Optional association
An association end that yields zero or one objects
Orthogonal state machine
The name given to a state machine when the statechart comprises two or more machines
Overriding
The redefinition by a sub-type of a feature inherited from a super-type
Parameterised property
An object property whose value depends on one or more parameters supplied when the property is evaluated
Parameterised type
An object type that uses a value type denoted only by a place-holder; the place-holder to be substituted by a value type when the object type is used
Post-condition
A logical expression used in statecharts that indicates the state of an object after an event or message has been detected/received
Pre-condition
A textual statement or logical predicate that indicates conditions which must hold for an event or message to be detected/received
Property
A named value owned by an object
Qualified association
A multiple association whose membership is partitioned by the value of a qualifier
Qualifier
A function signature used to select association members in a qualified association
Recursive association
An association where the source and the destination are the same object type
Relaxed section
The final section of an updater; other updaters of the same object can execute concurrently in other threads
Role name
The name attached to an association end to indicate its purpose
Secured section
The first section of an updater; it must execute in mutual exclusion with other secured sections and observers
self
The name given to the anonymous object used in a navigation expression to identify the starting point of the navigation; the anonymous object assumed to have detected the event or received the message in a statechart
Specification model
A model constructed to describe abstractly the structure and stimulus-response behaviour of a software system, assuming infinite resources and processing power
State view
A view of a model describing how its state changes over time
Statechart
A form of finite state machine used to describe the dynamic behaviour of objects
Sub-type
An object type such that objects conforming to it also conform to one or more other types (its super-type)
Super-type
An object type that has sub-types
Synchronisation expression
A logical predicate that controls the availability of operations in a non-exclusive contract
Synchronising type
An object type containing synchronisation expressions
Thread
A control path through the software
Type view
A view of a model describing its object types and their relationships
Updater
An operation that may cause a change in state of the system
Value
An immutable quantity whose identity is itself
Value type
A type whose members are values
View
A diagram describing one aspect of a model
Viewpoint
A subset of the features of an object type defined for use by a particular kind of client
Visibility
The ability to navigate an association in a particular direction

Comments, corrections to jdaniels@cix.co.uk