This is not in the spec and does pointless work:
- If either of them is true, we would determine the same result with the
manual code point iteration and comparison
- If neither of them is true, we iterate from the start again and repeat
the work that was just done
Instead, only have the manual loop from the spec and do a length
comparison at the end.
Removing it brings the following microbenchmark from ~5.5s down to ~3.5s
on my machine:
```js
const a = "x".repeat(100_000_000) + "a";
const b = "x".repeat(100_000_000) + "b";
a < b
```
After setting up all the bindings in function_declaration_instantiation,
we now ask DeclarativeEnvironment to do a shrink_to_fit() on its vector
of bindings.
This ends up saving 5.6 MiB on twitter.com/awesomekling :^)
Explicitly disallow constructing a CanonicalIndex from a floating point
type without going through a factory method that will throw when the
provided index cannot fit in a u32.
ErrorType::InvalidIndex does not encapsulate the reasons why an index
may be invalid. For example:
let array = new Uint8Array([1, 2, 3, 4, 5]);
array.with(10, 0);
Will currently yield:
[RangeError] Index must be a positive integer
Which is misleading because 10 *is* a positive integer.
Note that js_rope_string() has been folded into this, the old name was
misleading - it would not always create a rope string, only if both
sides are not empty strings. Use a three-argument create() overload
instead.
Three standalone Cell creation functions remain in the JS namespace:
- js_bigint()
- js_string()
- js_symbol()
All of them are leftovers from early iterations when LibJS still took
inspiration from JSC, which itself has jsString(). Nowadays, we pretty
much exclusively use static create() functions to construct types
allocated on the JS heap, and there's no reason to not do the same for
these.
Also change the return type from BigInt* to NonnullGCPtr<BigInt> while
we're here.
This is patch 1/3, replacement of js_string() and js_symbol() follow.
This makes more sense as an Object method rather than living within the
VM class for no good reason. Most of the other 7.3.xx AOs already work
the same way.
Also add spec comments while we're here.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
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 :^)
