.sdl
extension appended to its name. The
EditSDL
class, which implements the editor, is derived
from the EditProgram
class, and therefore inherits all of its features. Its facility
for tagging comments, strings, and keywords is inherited from this
base class.
http://www.tdr.dk/public/SDL
describes SDL:
SDL is a Specification and Description Language standardized by ITU (International Telecommunication Union). The language has been evolving since the first recommendation in 1980, 1984, 1988 and 1992 when Object Oriented features were included in the language. SDL is widely used in the telecommunications field.SDL is not directed specifically at describing telecommunications services, but it is a general purpose description language for communication systems. The basis for description of behaviour is communicating Extended State Machines that are represented by processes. Communication is represented by signals and can take place between processes or between processes and the environment of the system model. Some aspects of communication between processes are closely related to the description of system structure. An Extended State Machine consists of a number of states and a number of transitions connecting the states. One of the states is designated the initial state.