Matches a compact text run that ends with a URL scheme name.
The boundary is [^A-Za-z0-9] (not Text_Wiki's [^A-Za-z]) so that runs
like 123http stay fused, matching the non-compact lexer which tokenizes
123http as a single IDENTIFIER (such URLs are not auto-linked either way).
Matches a compact text run that ends with a URL scheme name.
The boundary is
[^A-Za-z0-9](not Text_Wiki's[^A-Za-z]) so that runs like123httpstay fused, matching the non-compact lexer which tokenizes123httpas a single IDENTIFIER (such URLs are not auto-linked either way).