Re^2: Aspect-Oriented Programming: Couple of Short Examples

Depends on the context.

Just because a technique can cause fragility does not mean that the entire technique is worthless. For example, I still use inheritance when appropriate - despite the fragile base class problem - because the benefits outweigh the problems.

AOP can be a powerful technique. It has an upside and a downside. Sometimes the benefits outweigh the costs. Sometimes the costs outweigh the benefits.

For example, implementing logging or persistence via aspects can make your application a lot less fragile in the face of change. If you need to change your logging system or persistence layer you just need to alter a single aspect - rather than manually update thousands of methods.

Sometimes, especially in languages like Java, AOP is the best technique to pick.

Comment on Re^2: Aspect-Oriented Programming: Couple of Short Examples

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Re^3: Aspect-Oriented Programming: Couple of Short Examples by rir (Vicar) on Aug 06, 2003 at 21:02 UTC
Depends on the context. I was responding to the mechanism as presented in this thread. I apologize for being unclear. Just because a technique can cause fragility does not mean that the entire technique is worthless. I don't think anyone suggested that the technique had no worth. Invasive code altering techniques like this have incredible power. The weakness is the shabby instrumentation used to control this power; correctly constructing the regexes requires visiting every function that falls within the applicable scope. Thereafter safely adding any function requires finding and reviewing every applicable regex. For example, I still use inheritance when appropriate - despite the fragile base class problem This is a very similar issue. It's nearly equivalent when the maintainers of the base class might be unaware that their code is being inherited. My first serious criticism of C++ was for its lack of a `DO_NOT_INHERIT_FROM_ME` mechanism. aspects can make your application a lot less fragile in the face of change. You're entitled to your opinion. I would like to see you support it. If you need to change your logging system or persistence layer you just need to alter a single aspect - rather than manually update thousands of methods. This is not support. This only points again to the power of AOP to quickly make sweeping changes, not to the resilience of the resultant code. I say there are no protections built into the system and that the locality of lexical reference is wrong. I can't imagine I'd plan to use AOP on a codebase that has not been written. Rather than use AOP I'd prefer to go one step further and use the regex and another tool to explicitly insert the desired code into the desired functions. If I am missing some bit of AOP that addresses these issues I'd be glad to be educated.	[reply] [d/l]

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Re^3: Aspect-Oriented Programming: Couple of Short Examples
by rir (Vicar) on Aug 06, 2003 at 21:02 UTC

Depends on the context.

I was responding to the mechanism as presented in this thread. I apologize for being unclear.

Just because a technique can cause fragility does not mean that the entire technique is worthless.

I don't think anyone suggested that the technique had no worth. Invasive code altering techniques like this have incredible power. The weakness is the shabby instrumentation used to control this power; correctly constructing the regexes requires visiting every function that falls within the applicable scope. Thereafter safely adding any function requires finding and reviewing every applicable regex.

For example, I still use inheritance when appropriate - despite the fragile base class problem

This is a very similar issue. It's nearly equivalent when the maintainers of the base class might be unaware that their code is being inherited. My first serious criticism of C++ was for its lack of a DO_NOT_INHERIT_FROM_ME mechanism.

aspects can make your application a lot less fragile in the face of change.

You're entitled to your opinion. I would like to see you support it.

If you need to change your logging system or persistence layer you just need to alter a single aspect - rather than manually update thousands of methods.

This is not support. This only points again to the power of AOP to quickly make sweeping changes, not to the resilience of the resultant code.

I say there are no protections built into the system and that the locality of lexical reference is wrong. I can't imagine I'd plan to use AOP on a codebase that has not been written. Rather than use AOP I'd prefer to go one step further and use the regex and another tool to explicitly insert the desired code into the desired functions.

If I am missing some bit of AOP that addresses these issues I'd be glad to be educated.

[reply]
[d/l]