operator
true if the specified stream is the #markup-parser stream and false otherwise. Replacing is with isnt will reverse the results.stream-name indexer? (is | isnt) markup-parser
A stream test that succeeds if the stream is the #markup-parser stream.
is sgml-parser is an older form of this test that is now deprecated. Note that is sgml-parser cannot be used to determine if the current parser is the SGML parser or the XML parser.