잘못된 S/W 디자인

Design Quality

What does it mean to be well designed? A system that is well designed is easy to understand,

easy to change, and easy to reuse. It presents no particular development difficulties,

is simple, terse, and economical.

잘 디자인(설계)된 프로그램은 위와 같은 특징들이 있음

Design Smells.

You know when a programmer is working with a poor design by the state of his eyes

and nose while he’s looking at the code. If his or her facial expression reminds you of the

detectives who have just opened a body bag containing a 12 day old corpse, then the

design is probably pretty ripe. The smells of a poor design have many different components.

1. Rigidity: The system is hard to change because every time you change one thing,

you have to change something else in a never ending succession of changes.

- 강직, 경직됨 : 시스템을 바꾸기 어려운 경우, 매번 바꾸었기 때문(스파게티 코드), 지속적인 변경이 필연적인 상황

2. Fragility: A change to one part of the system causes it to break in many other,

completely unrelated, parts.

- 단편, 깨지기 쉬움 : 하나의 변화 전체 시스템에 치명적 영향을 줌, Strongly Coupled~

3. Immobility: It is hard to disentangle the system into components that can be

reused in other systems.

- 부동성 : 시스템을 콤포넌트(다른 시스템에서 사용될 수 있는) 조합으로 분리해 내기 힘든 상황

4. Viscosity: The development environment is held together with scotch tape and

toothpaste. It takes forever to go around the edit, compile, test loop.

- 점착성 : 개발 환경에 지나친 의존성을 가지는 상황

5. Needless Complexity: There are lots of very clever code structures that aren’t

acutally necessary right now, but could be very useful one day.

- 불필요한 복잡성 : 당장 필요하지도 코드 구조가 존재하는 상황, 그러나 언젠가는 유용할 지도 모르는 코드임

6. Needless Repetition: The code looks like it was written by two programmers

named Cut and Paste.

- 불필요한 반복 : Ctrl C, V로 생산된 코드가 혼재하는 상황

7. Opacity: Elucidation of the originator’s intent presents certain difficulties

related to convolution of expression.

- 투명성 : 작성자의 의도에 대한 설명이 난해한 표현으로 어려움을 내포하고 있음