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Unicode support for XML and HTML tags name #196
Description
Tempest version
3.0
PHP version
8.5
Operating system
macOS
Description
Currently, for XML and HTML, we are capturing at best \w which translate into [a-zA-Z0-9_]. But tag names can contains almost any unicode characters after the first char (this one must be [a-zA-Z] for HTML, a bit more permissive for XML).
Here's the specs I've found for each language:
- XML: https://www.w3.org/TR/REC-xml/#NT-NameStartChar
- HTML: https://dom.spec.whatwg.org/#valid-element-local-name
The HTML spec even gave us a valid ReGex: /^(?:[A-Za-z][^\0\t\n\f\r\u0020/>]*|[:_\u0080-\u{10FFFF}][A-Za-z0-9-.:_\u0080-\u{10FFFF}]*)$/u
So the following are valid in HTML:
<math-α></math-α>
<emotion-😍-emoji></emotion-😍-emoji>(And I guess even GitHub doesn't render then correctly 🥲)
Here's how Gecko (Firefox) is rendering the above HTML:
Activity
Akiyo974 commentedon Oct 20, 2026
Hi @afu-dev , I opened #237 to fix this.
Tag name patterns for both HTML and XML now accept non-ASCII characters, so
<math-α>,<emotion-😍-emoji>and<données>are highlighted as a whole.<αtag>is not highlighted).NameStartChar.I kept the patterns byte-based (non-ASCII bytes
\x80-\xFF) rather than adding the/umodifier, so input with invalid UTF-8 still gets highlighted instead of failing silently.Unicode in attribute names isn't covered yet. I can open a follow-up PR if that's wanted.