Turns out the only difference between our existing implementation and
the ECMA-402 implementation is we weren't passing the locales and
options list to each element.toLocaleString invocation.
This also adds spec comments to the definition.
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
Also add slightly richer parse errors now that we can include a string
literal with returned errors.
This will allow us to use TRY() when working with JSON data.
This wasn't the case for compact patterns, but unit patterns can contain
multiple (up to 2, really) identifiers that must each be recognized by
LibJS.
Each generated NumberFormat object now stores an array of identifiers
parsed. The format pattern itself is encoded with the index into this
array for that identifier, e.g. the compact format string "0K" will
become "{number}{compactIdentifier:0}".
This field is currently used to store the StringView into the compact
name/symbol in the format string. Units will need to store a similar
field, so rename the field to be more generic, and extract the parser
for it.
Instead of currency pattern lookups within select_currency_unit_pattern,
rename the method to select_pattern_with_plurality and accept any list
of patterns. This method will be needed for units.
Currently, we get the following results
-1 - -2 = -1
-2 - -1 = 1
Correct would be:
-1 - -2 = 1
-2 - -1 = -1
This was already attempted to be fixed in 7ed8970, but that change was
incorrect. This directly translates to LibJS BigInts having the same
incorrect behavior - it even was tested.
Finding the best number format to use for compact notation involves
creating a Vector of all compact formats for the locale and looking for
the one that best matches the number's magnitude. ECMA-402 wants this
number format to be found multiple times, so cache the result for future
use.
The compact scale of each formatting rule was precomputed in commit:
be69eae651
Using the formula: compact scale = magnitude - pattern scale
This computation was off-by-one.
For example, consider the format key "10000-count-one", which maps to
"00 thousand" in en-US. What we are really after is the exponent that
best represents the string "thousand" for values greater than 10000
and less than 100000 (the next format key). We were previously doing:
log10(10000) - "00 thousand".count("0") = 2
Which clearly isn't what we want. Instead, if we do:
log10(10000) + 1 - "00 thousand".count("0") = 3
We get the correct exponent for each format key for each locale.
This commit also renames the generated variable from "compact_scale" to
"exponent" to match the terminology used in ECMA-402.
481f7d6afa tried to use `modulo()` here, but missed that the
code used `<=` instead of `<`.
Keep using `modulo()` and add an explicit conditional, which is
arguably clearer.
When the resulting week is in the previous year, we need to check if the
previous year is a leap year and can potentially have 53 weeks, instead
of the given year.
Also added a comment to briefly explain what's going on, as it took me a
while to figure out.
...and change the parameter types from i64 to double, as predicted by
a FIXME. The issue here is that integer division with a negative
dividend doesn't yield the same result as floating point division
wrapped in floor().
Additionally, the `days` variable needs to be signed.
I wanted to do this for a long time. The guts of Promise are pretty
complex, and it's easier to understand with the spec right next to it.
Also found a couple of issues along the way :^)
In order to implement Intl.NumberFormat.prototype.formatToParts, do not
replace {currency} keys in the format pattern before ECMA-402 tells us
to. Otherwise, the array return by formatToParts will not contain the
expected currency key.
Early replacement was done to avoid resolving the currency display more
than once, as it involves a couple of round trips to search through
LibUnicode data. So this adds a non-standard method to NumberFormat to
do this resolution and cache the result.
Another side effect of this change is that LibUnicode must replace unit
format patterns of the form "{0} {1}" during code generation. These were
previously skipped during code generation because LibJS would just
replace the keys with the currency display at runtime. But now that the
currency display injection is delayed, any {0} or {1} keys in the format
pattern will cause PartitionNumberPattern to abort.
There aren't any dangling views in as of yet, but a subsequent commit
will cause the "part" variable to be a view into an internally generated
string. Therefore, after returning from PartitionNumberPattern, that
view will be pointed at freed memory.
This commit is to set the precendence of not returning a view to "part".
This relies on floating point division, which is not possible with
LibCrypto bigints at the moment. So, instead of completely ignoring the
remainder we now first do a bigint division, then convert the remainder
to a double, and do another native floating point division to get the
final result.
It would crash because of VERIFY(largest_unit == "nanosecond"sv) in the
final else branch when passing "week", because it's not handled in any
of the previous branches.
Currencies are a bit strange; the layout of currency data in the CLDR is
not particularly compatible with what ECMA-402 expects. For example, the
currency format in the "en" and "ar" locales for the Latin script are:
en: "¤#,##0.00"
ar: "¤\u00A0#,##0.00"
Note how the "ar" locale has a non-breaking space after the currency
symbol (¤), but "en" does not. This does not mean that this space will
appear in the "ar"-formatted string, nor does it mean that a space won't
appear in the "en"-formatted string. This is a runtime decision based on
the currency display chosen by the user ("$" vs. "USD" vs. "US dollar")
and other rules in the Unicode TR-35 spec.
ECMA-402 shies away from the nuances here with "implementation-defined"
steps. LibUnicode will store the data parsed from the CLDR however it is
presented; making decisions about spacing, etc. will occur at runtime
based on user input.
Currently, LibUnicode is only parsing and generating the "long" style of
currency display names. However, the CLDR contains "short" and "narrow"
forms as well that need to be handled. Parse these, and update LibJS to
actually respect the "style" option provided by the user for displaying
currencies with Intl.DisplayNames.
Note: There are some discrepencies between the engines on how style is
handled. In particular, running:
new Intl.DisplayNames('en', {type:'currency', style:'narrow'}).of('usd')
Gives:
SpiderMoney: "USD"
V8: "US Dollar"
LibJS: "$"
And running:
new Intl.DisplayNames('en', {type:'currency', style:'short'}).of('usd')
Gives:
SpiderMonkey: "$"
V8: "US Dollar"
LibJS: "$"
My best guess is V8 isn't handling style, and just returning the long
form (which is what LibJS did before this commit). And SpiderMoney can
handle some styles, but if they don't have a value for the requested
style, they fall back to the canonicalized code passed into of().
