Saxon

With the move from @xsl:stream@ to @xsl:source-document@ it is possible to write XSLT 3.0 stylesheets that work with streaming in Saxon 9.8 EE and without in Saxon 9.8 HE, without needing to change the code.

Furthermore Saxon 9.8 HE for e.g. @<xsl:mode streamable="yes"/>@ also only emits a warning "Request for streaming ignored" that it ignores the streaming mode or construct and processes the code without streaming.

I am wondering whether the statement

A processor that does not claim conformance with the streaming feature is not required to use streamed processing and is not required to determine whether any construct is guaranteed streamable. Such a processor must, however, implement the semantics of all constructs in the language provided that enough memory is available to perform the processing without streaming.

in https://www.w3.org/TR/xslt-30/#streaming-feature can not be read as requiring Saxon HE to ignore an attribute like @streamable="absorbing"@ on a user -defined function and compile and execute a stylesheet with such a function as if it had the default value @unclassified@.

I currently get an error "XTSE3430: Streamable stylesheet functions are not supported in Saxon-HE" and execution is aborted in an example like

	
		
		
	  
	
	
	
	
		
List with {f:count-descendants(.)} descendant element(s).
	
	

I have found I can rewrite the function with a shadow attribute as

to make it work with EE and HE at the same time but I wonder whether that is necessary as other streaming features like streamed modes or streamed source documents are simply ignored in HE and executed without streaming.

Altova XMLSpy's XSLT processor which does not support streaming executes the code with

without giving errors.