Is there an existing issue for this?

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• I have read the guide to filing a bug

Use case

The current version of the web engine is doing some manual String parsing to convert navigator.locales into a List<ui.Locale> that Flutter can use.

However, the parsing is being done by hand:

• https://github.com/flutter/engine/blob/b39e6fe4b3bf98fdf20862c68177c2ed8a2785ec/lib/web_ui/lib/src/engine/platform_dispatcher.dart#L915-L922

Proposal

The parsing of the locale should instead be done with the Intl.Locale Constructor:

• MDN Intl.Locale constructor

Once it is sufficiently supported:

• https://caniuse.com/mdn-javascript_builtins_intl_locale_locale (Safari 14+)