From(.unicodeScalars) doesn't seem to work

[Lancelotbronner]

This is my parser, it seems to be trying to match Characters rather than unicode scalars and doesn't compile.

struct Identifier: ParserPrinter {
	var body: some ParserPrinter<Substring.UTF8View, String> {
		From(.unicodeScalars) {
			Prefix(1..., while: \.properties.isIDContinue)
				.filter(\.first!.properties.isIDStart)
		}
	}
}

[Lancelotbronner]

I've also tried From(.utf8), From(.substring) and just in case From(.string) but nothing seems to work.