Re: Scope of comments

Thanks for the speedy test, John!

Sent from my iPhone

> On 1 Feb 2022, at 17:01, John Lumley <john@saxonica.com> wrote:
> 
> 
>> On 01/02/2022 16:49, John Lumley wrote:
>> One of the issues I raised was how would 'specially marked' comments scope in the parsed XML for a grammar? I've just run a very small test, using my 'annotated' XPath.ixml which starts:
>> 
>> XPath: s?, Expr, s?. 
>> 
>> {# jl:opt rule} ParamList: {#jl:opt ruleStart} Param, ( -',', {#jl:opt inBracket} Param )*.
>> Param: -'$', EQName, TypeDeclaration?.
>> 
>> ....
>> 
>> If we pass this through Steven's processor against the grammar for IXML we get:
>> 
>> <ixml ixml:state="ambiguous" xmlns:ixml="http://invisiblexml.org/NS">
>> .......
>> so it seems that within a rule the comments scope within the tree, in appropriate sibling position. For those before a rule start, the comment is, unsurprisingly, in the preceding-sibling::*[1] position. I think anyone who's using this for preprocessing via a rule-rewriting operation through the XML representation could live with this small additional complexity.
>> 
> And the comments do also nest in the XML tree:
> 
> {# jl:opt rule} ParamList: {#jl:opt ruleStart} Param, ( -',', {#jl:opt inBracket {#jl:nest Nested}} Param )*.
> 
> becomes:
> 
>    <comment># jl:opt rule</comment>
>    <rule name='ParamList'>
>       <comment>#jl:opt ruleStart</comment>
>       <alt>
>          <nonterminal name='Param'/>
>          <repeat0>
>             <alts>
>                <alt>
>                   <literal tmark='-' sstring=','/>
>                   <comment>#jl:opt inBracket 
>                      <comment>#jl:nest Nested</comment>
>                   </comment>
>                   <nonterminal name='Param'/>
>                </alt>
>             </alts>
>          </repeat0>
>       </alt>
>    </rule>
> -- 
> John Lumley MA PhD CEng FIEE
> john@saxonica.com