- From: C. M. Sperberg-McQueen <cmsmcq@blackmesatech.com>
- Date: Thu, 14 Oct 2021 10:19:23 -0600
- To: Tom Hillman <tom@expertml.com>
- Cc: "C. M. Sperberg-McQueen" <cmsmcq@blackmesatech.com>, Steven Pemberton <steven.pemberton@cwi.nl>, public-ixml@w3.org
There’s an instance of this in the current ixml grammar for ixml (dchar, schar), so if JayParser produces a correct parse of that grammar, it passes this test. Michael > On 14,Oct2021, at 2:25 AM, Tom Hillman <tom@expertml.com> wrote: > > I think this is a great example of a test case, though: I'll have to test JayParser against this to be sure it won't fall over! > > _________________ > Tomos Hillman > eXpertML Ltd > +44 7793 242058 > On 13 Oct 2021, 16:11 +0100, C. M. Sperberg-McQueen <cmsmcq@blackmesatech.com>, wrote: >> Thank you; I had neglected, overlooked, or forgotten the words "regardless of marking of intermediate nonterminals”. >> >> Michael >> >>> On 13,Oct2021, at 3:16 AM, Steven Pemberton <steven.pemberton@cwi.nl> wrote: >>> >>> It may be just early in the morning and the coffee hasn't yet kicked in, but I don't see the problem. >>> >>> I checked in my implementation, making the grammar unambiguous in the process: >>> >>> S : @able, baker, @charlie. >>> able: string. >>> baker: string. >>> charlie: string. >>> string: ["abc"]*, ".". >>> >>> Input: >>> aaa.bbb.ccc. >>> >>> Result: >>> <S able='aaa.' charlie='ccc.'> >>> <baker> >>> <string>bbb.</string> >>> </baker> >>> </S> >>> >>> Which was what I was expecting. >>> >>> So assuming I'm not missing something obvious, I suspect that you need to reread the serialisation section of the spec: >>> >>> " >>> • A nonterminal attribute is serialised by outputting the name of the node as an attribute, and serialising all non-hidden terminal descendants of the node (regardless of marking of intermediate nonterminals), in order, as the value of the attribute. >>> " >>> which I think covers what you are asking for. >>> >>> The other side of this coin is: >>> >>> " >>> • A nonterminal element is serialised by outputting the name of the node as an XML tag, serialising all exposed attribute descendants, and then serialising all non-attribute children in order. An attribute is exposed if it is an attribute child, or an exposed attribute of a hidden element child (note this is recursive). >>> " >>> >>> Steven >>> >>> On Wednesday 13 October 2021 04:19:52 (+02:00), C. M. Sperberg-McQueen wrote: >>> >>>> Consider the grammar >>>> >>>> S : @able, baker, @charlie. >>>> able: string. >>>> baker: string. >>>> charlie: string. >>>> string: ~[]*. >>>> >>>> Is this grammar OK? (Yes, it’s hopelessly ambiguous, but that’s beside the point.) >>>> >>>> If we ignored the annotations, a raw parse tree for this grammar might look like this: >>>> >>>> <S> >>>> <able mark=“@"><string>aaa</string></able> >>>> <baker><string>aaa</string></able> >>>> <charlie mark=“@"><string>ccc</string></able> >>>> </S> >>>> >>>> Note that ‘string’ is implicitly marked serializable (^). >>>> >>>> When a nonterminal marked to be serialized as an element appears as a child of a nonterminal marked to be serialized as an attribute (as ’string’ here appears as a child of @able and @charlie), is the rule >>>> >>>> - Raise an error because the grammar cannot be serialized that way? >>>> >>>> - Omit the content of ’string’ from the value of @able and @charlie by analogy with what happens when we calculate the text node children of an element? >>>> >>>> - Ignore the marking on ’string’ on the grounds that we have already been told that @able is an attribute. Since elements cannot appear within attributes, the implicid ^ marking on ’string’ is ignored. >>>> >>>> The grammar for ixml offers two examples that seem relevant: in a raw parse tree, @name will dominate nodes labeled namestart and namefollower, which are explicitly marked non-serializable (-). @dstring and @sstring similarly dominate nodes labeled dchar and schar, which are implicitly marked ^. The attributes @from and @to directly dominate nodes labeled ‘character’ (marked -) and indirectly dominate nodes labeled ‘dchar’ and ’schar’ (implicitly ^). >>>> >>>> In the spirit of making things as simple as possible for the grammar authors, I suppose the right rule is “when constructing the value of an attribute, treat nonterminals marked ^ and - the same: recur through them” (the last possibility mentioned above). >>>> >>>> I apologize if this has been discussed before - I have the guilty sensation that it has been, and that I did not retain the answer. >>>> >>>> Michael >>>> >>>> >>>> >>>> >> >>
Received on Thursday, 14 October 2021 16:18:52 UTC