1) I'm not sure i agree. The extension is metadata associated with the file that's not part of the name. The ui for exposing it makes it look the same, but that's cosmetic.
2) There is absolutely nothing stopping you from creating long URI like extensions today. And have them work fully on every OS since Windows 95. The fact a lot of people seemed inexplicably wedded to 3 character extensions is not all that relevant.
3) There is already a web service integrated into Windows that can associate file extensions with any and all the rich processing capabilites that URIs would give you. And yet nobody bothers using it, so the end result of clicking on an unknown file type
is you don't get useful data about the file you have in most cases. Replacing the extension with a URI isn't going to change that.
4) I fail to see how, in truth both are just arbitrary text strings. Any mechanism you apply to one could just as easily be applied to the other.
1) It's not cosmetic. At the API level it *IS* part of the name. This leaks to the end-user all over the place. The "hack" of hiding the file extension (something that I think is a horrid idea, and ALWAYS disable) is at best a stop-gap attempt. For example,
on the command line you can't access the file without specifying the full name, which includes the extension. There's no reason this metadata needs to exist within the name... and therein lies the religious argument aspect of this whole discussion. On that
front, I'm not taking sides.
2) There's several things preventing you from doing it today. First, URIs and file names have different requirements when it comes to acceptible characters. A URI accepts '/', while that character has very specific meaning in a path and thus can't be part
of a file name. Then there's the issue that started this thread... file name lengths. I could go on, but I think I've made my point.
3) From a technical point of view, you are at least partially correct. However, from a psychological and human nature point of view, I think you're entirely wrong. People EXPECT certain things out of a URI, that they don't expect out of a file extension.
More important, however, is that the file extension "rich processing" capabilities rely on fragile central registry mapping, while URIs are democratized.
4) The main difference here is how that metadata is stored. With the URI scheme, it's stored in a single lookup table, while with a file extension it's stored in the file name. One is space efficient, while the other is not. Again, this also relates to the
original topic of this thread about file name lengths.