Object Constraint Language

Two different navigation paths may refer to the same object for example, the object referred to as my boss may be the same object as that referred to as my friend s wife. In Figure 2.2, session-5.instructor and session-32.instructor both refer to the same object, laura. If both names refer to the same object, they both see the same attribute values and changes to those values, x = y means x and y refer to same object x <> y means that x and y refer to different objects. These symbols are based on the Object Constraint Language (OCL) in UML in C++ and Java we d use == and =. 

These are also based on the UML s Object Constraint Language. 

Well-written postconditions can be used as the basis for verification and testing. For this purpose, we should write the postconditions in a more precise style as test (Boolean) functions. You can use the Boolean expression part of your favorite programming language we will use a general syntax from UML called Object Constraint Language (OCL). It translates readily to most programming languages but is more convenient for specification. 

The Object Constraint Language (OCL), a standard part of UML 1.1, is a specification language used in conjunction with UML models. It is an expression-based, side-effect-free language that eschews mathematical symbols (V, 3, and so on) for textual equivalents (forAII, exists). It uses a syntax more usual in object-oriented languages V x T, p(x) becomes T->forAII (x x.p). 

So far, only the structural aspects of link templates and rules were addressed. In practice, each increment is further defined by some attributes and their values. Using a subset of the OCL language (Object Constraint Language [879], part of the UML specification), conditions based on these attributes that further constrain the applicability of the resulting integration rules can be added to link templates. 

We consider that UML is a useful notation for displaying graphically the structure of a system and the relationships between the system, its components and its users. However, UML is not a substitute for a precise formal specification. Although UML has a formal sub-language called Object Constraint Language (OCL), it is rarely used, poorly supported by commercial tools and much less expressive than Perfect Developer notation. 

The Unified Modeling Language (UML) (UML,2010a) (UML,2010b) combined with the Object Constraint Language (OCL) (OCL, 2010) is the most widely used way for writing... 

Retrieved October 2011 from www.omg.org/mof OCL (2010). OCL Object Constraint Language. Version 2,2. OMG formal/2010-02-01.Retiieved October 2011 from www.omg.org... 

UML Revision Task Force OMG Object Constraint Language Reference (February 2010)... 

The behavior of the plant process can be represented as states and transition among the different states. Also messages and collaboration among the different classes/objects can represent behavioral aspects of the plant. Equations controlling the transition from one state to another can be represented using object constraint language (OCL) as an associated code with the different classes and states. 

Examples of the formal UML definitions have been described by Gabbar (2001c). For the purpose of representing the plant design and simulation models, mathematical equations solver is needed (Linninger et al., 1999). OCL as a standard object-constraint language has been used within UML to enable defining constraints associated with each model element. For that it is proposed to enable the mathematical equations representation within OCL. 

Object Management Group Constraint Language (OCL), Version 2.4 (2014). http //www.omg.org/ spec/OCL/2.4/... 

Scatter search has been implemented in software called OPTQUEST (see www.opttek.com). OPTQUEST is available as a callable library written in C, which can be invoked from any C program, or as a dynamic linked library (DLL), which can be called from a variety of languages including C, Visual Basic, and Java. The callable library consists of a set of functions that (1) input the problem size and data, (2) set options and tolerances, (3) perform steps 1 through 3 to create an initial reference set, (4) retrieve a trial solution from OPTQUEST to be input to the improvement method, and (5) input the solution resulting from the improvement method back into OPTQUEST, which uses it as the input to step 7 of the scatter search protocol. The improvement method is provided by the user. We use the term improvement loosely here because the user can simply provide an evaluation of the objective and constraint functions. 

Schema evolution primitives in the SQL language and in commercial DBMS are atomic in nature. Unless there is a proprietary extension to the language, each statement describes a simple change to a schema. For instance, individual tables may be added or dropped, individual columns may be added or dropped from a table, and individual constraints may be added or dropped. Additionally, individual properties of a single object may be changed so, one can rename a column, table, or constraint one can change individual properties of columns, such as their maximum length or precision and one can change the data type of a column under the condition that the conversion of data from the old type to the new type can be done implicitly.

Java RMI (remote method invocation) is offered as a part of the JAVA language specification and win be a language-dependent method for the distributed object environment. Although there is the constraint that aU the environments should be unified into Java, the developing process with it is a little easier than with CORBA or RPC because several functions for distributed computing are offered as utility objects. 

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