Tokenises a single source-code line into coloured text segments.
Return null to signal that the language is unsupported; the
caller should fall back to plain monochrome rendering.
An empty list means the language is supported but the line produces no tokens.
public interface ICodeHighlighter
kind:method, kind:property, kind:ctor. Press Esc to clear.Highlight(ReadOnlyMemory<Char>, String?, ref Object?)Highlights line from the state the previous line of its block ended in, so a construct that spans lines (a block comment, a multi-line string) is coloured on every line it covers. state is null for the first line of a block and receives the state this line ends in, to pass with the next line. The default ignores it and highlights the line on its own.