OBJECT-ORIENTED PARADIGM AS EVOLUTION OF STRUCTURED APPROACH IN PROGRAMMING

摘要

A viewpoint is given about structured programming (SP) as a fundamental approach for complex software system development independent from procedural paradigm. The multi-interface program module form - class, entered in object-oriented paradigm (OOP) is considered as a long evolutionary process in informatics aiming to improve SP efficiency. A new form of structured algorithm is proposed as a collection of functional threads corresponding to universal function F{sub}(generic). Four possible implementations of F{sub}(generic) in procedural and object-oriented paradigms are given and compared. Functional library with hidden global data structure is considered as a procedural form of class entered in software engineering to improve SP efficiency for complex system development using procedural programming languages. The second software crisis in procedural SP is explained by defining the task to find all functional threads in complex system needed for testing as NP-hard problem. Statistic data about extremely reduce of programmer's productivity in large software projects are discussed and a function extrapolated statistic data is used for the forecast of programmer's productivity as a function of system size and complexity. Using the object-oriented interpretations of F{sub}(generic) some of the concepts of OOP such as static and dynamic polymorphism are discussed.