This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).
This commit is auto-generated:
$ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
Meta Ports Ladybird Tests Kernel)
$ perl -pie 's/\bDeprecatedString\b/ByteString/g;
s/deprecated_string/byte_string/g' $xs
$ clang-format --style=file -i \
$(git diff --name-only | grep \.cpp\|\.h)
$ gn format $(git ls-files '*.gn' '*.gni')
The main change is the simplification of the expression
`(10^precision * fraction) / 2^precision` to `5^precision * fraction`.
Those expressions overflow or not depends on the value of `precision`
and `fraction`. For the maximum value of `fraction`, the following table
shows for which value of `precision` overflow will occur.
Old New
u32 08 10
u64 15 20
u128 30 39
As of now `u64` type is used to calculate the result of the expression.
Meaning that before, only FixedPoints with `precision` less than 15
could be accurately rendered (for every value of fraction) in decimal.
Now, this limit gets increased to 20.
This refactor also fixes, broken decimal render for explicitly specified
precision width in format string, and broken hexadecimal render.
Because of the off-by-one error, the second bit of the fraction was
getting ignored in differentiating between fractions equal to 0.5 or
greater than 0.5. This resulted in numbers like 2.75 being considered
as having fraction equal to 0.5 and getting rounded incorrectly (to 2).
This is needed to have code for creating an in-memory sRGB profile using
the (floating-ppoint) numbers from the sRGB spec and having the
fixed-point values in the profile match what they are in other software
(such as GIMP).
It has the side effect of making the FixedPoint ctor no longer constexpr
(which seems fine; nothing was currently relying on that).
Some of FixedPoint's member functions don't round yet, which requires
tweaking a test.
As a nearby comment says, "This is a terrible approximation".
This doesn't make things less terrible, but it does make things
more correct in the given framework of terribleness.
Fixes#17156.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Rather than casting the FixedPoint to double, format the FixedPoint
directly. This avoids using floating point instruction, which in
turn enables this to be used even in the kernel.
