PSR-4是否仅适用于小包装？

Question

After reading the PSR-4 , I think that it'll just fit the small packages which have few directories.
If the packages are big, it'll have so many autoload functions to load from the subpackages. (because we need to tell the function the base directory first)
Consider a CMS or Framework

• admin
• extensions
• lib
• framework
• abstract
• database
• datetime
• functions
• Interface
• comment
• post
• user

Is PSR-0 better for this CMS package than PSR-4?
Is my directory structure good ?
Should interface and abstract classes have their own directory?

Answer 1

Is PSR-4 just for small package?

No, PSR-4 is not just for small packages. Standard frameworks like Zend and Symfony use it, too.

PSR-4 describes a specification for autoloading classes from file paths. It makes no assumptions about the size of your project. It is fully interoperable, and can be used in addition to any other autoloading specification. That means you can also use PSR-0.

Is PSR-0 better for this CMS package than PSR-4?

It depends. If your system uses namespaces to avoid classname clashes with other vendors, then PSR-4 is the right choice. But in general: the Autoloader doesn't care, he just eats PSR-0 and PSR-4 classes for breakfast.

If you really want to know: do an A/B test and compare the autoloading speed.

Is my directory structure good ?

It depends: if you and the users of your CMS or Framework like the structure, then yes. If you work with Composer for dependency management, then probably lib\\ framework is a dead horse, because all packages live inside the vendor folder. If you develop a CMS, then the framework is a vendor dependency.

Should interface and abstract classes have their own directory?

I would suggest to keep an interface or abstract base class in the same directory.

This saves you one folder ,) for only one or two files.