This brings the function name in line with how we usually name those
functions, which is with a `read_` or `write_` prefix depending on what
they do.
While at it, make the internal `_impl` function private and not-virtual,
since there is no good reason to ever override that function.
Based on `out()` and `vout()` from AK/Format.h. As opposed to those,
this propagates errors.
As `Core::File` extends `AK::Stream`, this allows formatted
printing directly on `Core::File`s.
Similar to POSIX read, the basic read and write functions of AK::Stream
do not have a lower limit of how much data they read or write (apart
from "none at all").
Rename the functions to "read some [data]" and "write some [data]" (with
"data" being omitted, since everything here is reading and writing data)
to make them sufficiently distinct from the functions that ensure to
use the entire buffer (which should be the go-to function for most
usages).
No functional changes, just a lot of new FIXMEs.
It wouldn't make much sense on its own (as the Kernel only has errno
Errors), but it's an easy fix for not having to ifdef away every single
usage of `is_errno` in code that is shared between Userland and Kernel.
This code should not be used in the kernel - we should always propagate
proper errno codes in case we need to return those to userland so it
could decode it in a reasonable way.
`Stream` will be qualified as `AK::Stream` until we remove the
`Core::Stream` namespace. `IODevice` now reuses the `SeekMode` that is
defined by `SeekableStream`, since defining its own would require us to
qualify it with `AK::SeekMode` everywhere.
