Do I need to specify vendor_name/package_name when creating a package?

Question

linux

I got lost in three pines, although I thought that I knew everything.
When I was looking into composer, I was looking at third party packages on packagist.org and noticed a trend that packages are named as vendor_name/package_name :

"autoload-dev": {
        "psr-4": {
            "Vendor\\Library\\": "src"
        }
    },

which seemed quite logical to me - a supplier can have many packages.
Now I re-read PSR-4 and was surprised - it turns out that there is no such requirement anywhere - to indicate exactly this notation:

A fully qualified class name must have the following structure: \<Namespace>(\<SubNamespace>)*\<ClassName>

- roughly speaking, the standard requires only specifying the Supplier in the <Namespace>, and what <SubNamespace> will be - no one cares.
I looked at the yii sources and did not understand how they managed to ensure that they use a single top-level namespace - yii, although, in the app-base composer.json they have

"require": {
        "yiisoft/yii2": "~2.0.6",
        "yiisoft/yii2-bootstrap": "~2.0.0",
        "yiisoft/yii2-swiftmailer": "~2.0.0 || ~2.1.0"
    },

those. in the use code should be yiisoft / yii22, but they just use yii
How did they achieve this and why does this go against the composer's ideology?

Answer 1

normalize || Reset CSS . Font rendering will still be different.