About Software Reuse

In most real projects, we are considering the issue of software reuse, because this is a very realistic problem that cannot be avoided in software development, it is also a headache. The following is my personal understanding of software reuse for reference only.

Software reuse can be divided into two levels: one is design reuse, the other is code-level reuse, and the code-Level Reuse can be divided into two levels, one is source code-based reuse, and the other is component-based reuse.

Whether it is the waterfall development model in the past or the more popular agile development, it all reflects the "design first" viewpoint. Although agile focuses more on code, it also emphasizes simple design. The reuse of design is often reflected in the reuse of the knowledge of one thing or field. For example, we have designed a typographical system. What we want to reuse may be the typographical rules and core concepts related to the typographical field, different typographical systems can reuse these core rules and concepts to build their own systems. This reuse method is very abstract, so it has the highest degree of reuse, and is also the most difficult. MDA highlights the reuse at the design level.

In fact, in real projects, the reuse we mentioned is often code-Level Reuse. Different platforms have different views on reuse. com and. Net platforms emphasize component-Level Reuse, while STL emphasizes source-Level Reuse. There is no saying that the two are both superior and inferior, and they have their own advantages in different projects.

However, the biggest drawback of source code reuse is that it is restricted by programming languages. For example, STL code can only be used by C ++ programs. Component-based reuse is different.. Net emphasizes the unification of platforms. Therefore, a component written in C # can be reused by VB. NET or VC ++/CLI programs. From this perspective,. Net emphasizes more component-Level Reuse, so component-Level Reuse requires the unification of the platform. Currently,. Net implements different programming language architectures on the same platform, that is, CLI, such as C ++/CLI and Python/CLI.

From Com to. net, Microsoft has always adhered to the idea of component-Level Reuse. This is a trend. After all, source code reuse has many defects, and it is too difficult to design-Level Reuse. Some organizations are also working in this direction, but the current results are not very obvious. Therefore, for the moment, we should pay more attention to component-Level Reuse.