Merge Format into MediaType

[mickael-menu]

• Format got merged into MediaType, to simplify the media type APIs.
  • You can use MediaType.of() to sniff the type of a file or bytes.
  • MediaType has now optional name and fileExtension properties.
  • Some publication formats can be represented by several media type aliases. Using mediaType.canonicalized will give
    you the canonical media type to use, for example when persisting the file type in a database. All Readium APIs are
    already returning canonical media types, so it only matters if you create a MediaType yourself from its string
    representation.

[qnga]

Great, that's better this way.

Just one thing that was already here in the previous version: I'm not sure readFileSignature should decode bytes and return a String. Generally speaking, a magic number is a sequence of bytes, not necessarily a string. In the worst case, it might not make sense in any encoding. What do you think of it?

[mickael-menu]

Just one thing that was already here in the previous version: I'm not sure readFileSignature should decode bytes and return a String. Generally speaking, a magic number is a sequence of bytes, not necessarily a string. In the worst case, it might not make sense in any encoding. What do you think of it?

You have a point, I'll update the proposal. I returned a string to make ASCII-based magic number (e.g. %PDF) more visible, but it can still be done on the client side of this API.

[mickael-menu]

Although the API looks a bit contrived now: readFileSignature(length: Int) -> ByteArray?.

I think we might as well remove it and introduce read(range) -> ByteArray? instead.

[qnga]

Sounds good!