For example, if most
behavior is provided by the underlying framework, we can produce just structure and
interface data. This suggests the use of languages addressing static structures and is
often the easiest way to achieve model-based code generation. Although we can
generate functional and behavioral code from models describing static structures (like
schema creation for a database), the possibilities of specifying behavior, logic,
dynamics, and interaction are easier with languages addressing behavior, such as
various ?¬‚ow diagrams, state models, and interaction diagrams.
FIGURE 10.5 Modeling call processing in IP telephony, a DSM language based on its XML
generation target
238 DSM LANGUAGE DEFINITION
Library of MOCs The easiest way to start de?¬?ning a modeling language is to base
it on the computational model of an existing language??”which already has some
proven structures. Tools may help here by offering a library of basic metamodels to
start with. You can then copy ideas, or sometimes even concrete elements of the
metamodel, into your language and extend them with domain-speci?¬?c concepts. Such
concepts can be new modeling objects, their relationships, properties, bindings,
constraints, model hierarchies, reuse rules, and so on. You have here numerous
possibilities. Consider, for example, a relationship between model elements.
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