Henri Sivonen

Prepare for future normalization data for Unicode 16

1

ICU4X's data representation doesn't have a place for marking the first character of an expansion as a starter that combines backwards. To accommodate the Unicode 16 characters discussed in section...

Provide UTS 46 mapping / disallow operations fused with normalization

12

Gecko implements most of its IDNA processing on its own, but it currently uses ICU4C's `uidna_labelToUnicode` for UTS 46 processing. Code that wraps `ComposingNormalizer::try_new_uts46_without_ignored_and_disallowed_unstable` and augments it to provide the...

Consider returning std::weak_ordering from C++20 binding for the Collator::compare

2

C++20 added [`std::weak_ordering`](https://en.cppreference.com/w/cpp/utility/compare/weak_ordering), which logically corresponds to Rust's `core::cmp::Ordering`. AFAICT, Rust's `code::cmp::Ordering` has the bit representation of `i8` `-1`, `0`, and `1` while `std::weak_ordering` in practice the C++ `int` representation...

Investigate removing scalar value validation from HarfBuzz canonical composition and decomposition

8

The initial glue code for providing the canonical composition and canonical decomposition operation to HarfBuzz assumes that the incoming `hb_codepoint_t` values might not be valid scalar values. We should investigate...

Initialize the IgnoreInvalidPunycode flag when calling UTS 46

3

### What is the issue with the URL Standard? UTS 46 revision 31 added a _IgnoreInvalidPunycode_ flag to its ToASCII and ToUnicode operations. The URL Standard should be explicit about...

### What is the issue with the URL Standard? https://url.spec.whatwg.org/#concept-domain-to-ascii has a _beStrict_ flag to validation. This flag affects the _UseSTD3ASCIIRules_ and _VerifyDnsLength_ flags for UTS 46 processing, but don't...

### What is the issue with the URL Standard? The URL Standard gives advice about URL rendering: https://url.spec.whatwg.org/#ref-for-concept-domain-to-unicode%E2%91%A0 It also in the https://url.spec.whatwg.org/#concept-host-parser section says: "Alternatively [UTF-8 decode without BOM...

Hoist "forbidden domain code point" check into "domain to ASCII"

4

### What is the issue with the URL Standard? When reading https://url.spec.whatwg.org/#concept-domain-to-ascii in isolation of https://url.spec.whatwg.org/#concept-host-parser (and without reading ICU4C's uts46.cpp first), it's not at all apparent that 1) STD3...

Clearly mark conformance checking-only aspects of the IDNA section

1

### What is the issue with the URL Standard? When reading https://url.spec.whatwg.org/#idna in isolation to find out what kind of IDNA library surface the URL Standard needs, it's not apparent...

Explain why valid domain needs to run ToUnicode

3

### What is the issue with the URL Standard? https://url.spec.whatwg.org/#valid-domain could use an informative note that states the implications of the two-step (both ToASCII and ToUnicode) check. Given the how...