- From: Gregg Kellogg <gregg@greggkellogg.net>
- Date: Sun, 7 Jul 2013 22:33:04 -0600
- To: Eric Prud'hommeaux <eric@w3.org>
- Cc: Andy Seaborne <andy@apache.org>, RDF WG <public-rdf-wg@w3.org>
On Jul 7, 2013, at 10:27 PM, Eric Prud'hommeaux <eric@w3.org> wrote:
> * Gregg Kellogg <gregg@greggkellogg.net> [2013-07-07 15:22-0600]
>>
>> Gregg Kellogg
>> gregg@greggkellogg.net
>>
>> On Jul 6, 2013, at 4:49 PM, Eric Prud'hommeaux <eric@w3.org> wrote:
>>
>>> https://www.w3.org/2011/rdf-wg/track/actions/278 says
>>> [[
>>> Create new grammar for TriG that includes optional graph keywords and
>>> make {} optional around the default graph
>>> ]]
>>>
>>> I followed Sandro's lead and replaced
>>> [[
>>> [1] turtleDoc ::= statement*
>>> [2] statement ::= directive | triples '.'
>>> ]]
>>> with:
>>> [[
>>> trigDoc ::= statement*
>>> statement ::= directive | tripleOrBareGraph | graphword | wrappedDefault
>>> tripleOrBareGraph ::= (iri | BlankNode | collection | BlankNodePropertyList) ('{' TriplesTemplate '}' | PropertyListNotEmpty '.')
>>> graphword ::= "GRAPH" (iri | BlankNode) '{' TriplesTemplate '}'
>>> wrappedDefault ::= '{' TriplesTemplate '}'
>>> ]].
>>> This permits docs like:
>>> [[
>>> PREFIX p: <ns>
>>> @prefix p: <ns> .
>>> <s> <p> <o> .
>>> { <s> <p> <o> }
>>> <g> { <s> <p> <o> }
>>> GRAPH <g> { <s> <p> <o> }
>>> _:g { <s> <p> <o> }
>>> GRAPH _:g { <s> <p> <o> }
>>> ]].
>>>
>>>
>>> We can be conservative or liberal about what can go the the graph name
>>> position:
>>> [[
>>> tripleOrBareGraph ::= (iri | BlankNode) ('{' TriplesTemplate '}' | PropertyListNotEmpty '.')
>>> | collection PropertyListNotEmpty '.'
>>> | BlankNodePropertyList PropertyListNotEmpty? '.'
>>> [[
>>> or more liberal:
>>> [[
>>> tripleOrBareGraph ::= (iri | BlankNode | collection | BlankNodePropertyList) ('{' TriplesTemplate '}' | PropertyListNotEmpty '.')
>>> ]]
>>> which permits bnodes from collections and property lists like:
>>> [[
>>> (1 2 3) { <s> <p> <o> }
>>> [ <p> <o> ] { <s> <p> <o> }
>>> ]].
>>> I prefer the latter as it encourages the good practice of making
>>> assertions about labeled graphs, e.g.
>>> [[
>>> [ :utteredBy "Bob" ] { <moon> <madeOf> <greenCheese> }
>>> ]]
>>
>> A problem with this grammar is that it doesn't allow Andy's test trig-turtle-05.trig [1]:
>>
>> [[
>> # Turtle is TriG
>> prefix : <http://example/>
>>
>> [ :p :o ] .
>> ]]
>>
>> This is because the BlankNodePropertyList matches the first element of tripleOrBarGraph, and it expects to see a PropertyListNotEmpty '.'
>>
>> SPARQL doesn't suffer from this problem, as a graph name can't be a collection of BlankNodePropertyList.
>>
>> I find the following version of tripleOrBareGraph works:
>>
>> [[
>> [3g] tripleOrBareGraph ::= (iri | BlankNode) (wrappedDefault | PropertyListNotEmpty '.')
>> | (collection | BlankNodePropertyList) (wrappedDefault | PropertyListNotEmpty? '.')
>>
>> ]]
>
> agreed. I pass all of Andy's tests with this grammar.
Strictly Speaking, collection should be in the first part, and not the second, as a collection is not legal stand-alone in Turtle, neither should it be in TriG.
Gregg
>> Gregg
>>
>> [1] https://dvcs.w3.org/hg/rdf/file/1f470c4ebbc0/trig/tests2/trig-turtle-05.trig
>>
>>
>>> Following is <http://www.w3.org/2005/01/yacker/uploads/trigS_new>:
>>>
>>> trigDoc ::= statement*
>>> statement ::= directive | tripleOrBareGraph | graphword | wrappedDefault
>>> #tripleOrBareGraph ::= (iri | BlankNode) ('{' TriplesTemplate '}' | PropertyListNotEmpty '.')
>>> # | collection PropertyListNotEmpty '.'
>>> # | BlankNodePropertyList PropertyListNotEmpty? '.'
>>> tripleOrBareGraph ::= (iri | BlankNode | collection | BlankNodePropertyList) ('{' TriplesTemplate '}' | PropertyListNotEmpty '.')
>>> graphword ::= "GRAPH" (iri | BlankNode) '{' TriplesTemplate '}'
>>> wrappedDefault ::= '{' TriplesTemplate '}'
>>>
>>> [3] directive ::= prefixID | base | sparqlPrefix | sparqlBase
>>> [4] prefixID ::= PREFIX PNAME_NS IRIREF '.'
>>> [5] base ::= BASE IRIREF '.'
>>> [5s] sparqlBase ::= SPARQL_BASE IRIREF
>>> [6s] sparqlPrefix ::= SPARQL_PREFIX PNAME_NS IRIREF
>>> [52s] TriplesTemplate ::= TriplesSameSubject ( '.' TriplesTemplate? )?
>>> [6] TriplesSameSubject ::= subject PropertyListNotEmpty | BlankNodePropertyList PropertyList
>>> [76s] PropertyList ::= PropertyListNotEmpty?
>>> [77s] PropertyListNotEmpty ::= Verb ObjectList (';' (Verb ObjectList)?)*
>>> [8] ObjectList ::= object (',' object)*
>>> [9] Verb ::= predicate | 'a'
>>> [10] subject ::= iri | BlankNode | collection
>>> [11] predicate ::= iri
>>> [12] object ::= iri | BlankNode | collection | BlankNodePropertyList | literal
>>> [13] literal ::= RDFLiteral | NumericLiteral | BooleanLiteral
>>> [14] BlankNodePropertyList ::= '[' PropertyListNotEmpty ']'
>>> [15] collection ::= '(' object* ')'
>>> [16] NumericLiteral ::= INTEGER | DECIMAL | DOUBLE
>>> [128s] RDFLiteral ::= String (LANGTAG | '^^' iri)?
>>> [133s] BooleanLiteral ::= 'true' | 'false'
>>> [17] String ::= STRING_LITERAL1 | STRING_LITERAL2 | STRING_LITERAL_LONG1 | STRING_LITERAL_LONG2
>>> [135s] iri ::= IRIREF | PrefixedName
>>> [136s] PrefixedName ::= PNAME_LN | PNAME_NS
>>> [137s] BlankNode ::= BLANK_NODE_LABEL | ANON
>>>
>>> @terminals
>>>
>>> [18] IRIREF ::= '<' ([^#x00-#x20<>\"{}|^`\\] | UCHAR)* '>'
>>> [139s] PNAME_NS ::= PN_PREFIX? ':'
>>> [140s] PNAME_LN ::= PNAME_NS PN_LOCAL
>>> [141s] BLANK_NODE_LABEL ::= '_:' (PN_CHARS_U | [0-9]) ((PN_CHARS | '.')* PN_CHARS)?
>>> [0] GRAPH1 ::= [Gg][Rr][Aa][Pp][Hh]
>>> [0] SPARQL_PREFIX ::= [Pp][Rr][Ee][Ff][Ii][Xx]
>>> [0] SPARQL_BASE ::= [Bb][Aa][Ss][Ee]
>>> [0] BASE ::= '@base'
>>> [0] PREFIX ::= '@prefix'
>>> [144s] LANGTAG ::= BASE | PREFIX | '@' [a-zA-Z]+ ('-' [a-zA-Z0-9]+)*
>>> [19] INTEGER ::= [+-]? [0-9]+
>>> [20] DECIMAL ::= [+-]? [0-9]* '.' [0-9]+
>>> [21] DOUBLE ::= [+-]? ([0-9]+ '.' [0-9]* EXPONENT | '.' [0-9]+ EXPONENT | [0-9]+ EXPONENT)
>>> [154s] EXPONENT ::= [eE] [+-]? [0-9]+
>>> [155s] STRING_LITERAL1 ::= "'" ([^#x27#x5C#xA#xD] | ECHAR | UCHAR)* "'"
>>> [156s] STRING_LITERAL2 ::= '"' ([^#x22#x5C#xA#xD] | ECHAR | UCHAR)* '"'
>>> [157s] STRING_LITERAL_LONG1 ::= "'''" (("'" | "''")? [^'\\] | ECHAR | UCHAR)* "'''"
>>> [158s] STRING_LITERAL_LONG2 ::= '"""' (('"' | '""')? [^"\\] | ECHAR | UCHAR)* '"""'
>>> [26] UCHAR ::= '\\u' HEX HEX HEX HEX | '\\U' HEX HEX HEX HEX HEX HEX HEX HEX
>>> [159s] ECHAR ::= '\\' [tbnrf\\"']
>>> [161s] WS ::= #x20 | #x9 | #xD | #xA
>>> [162s] ANON ::= '[' WS* ']'
>>> [163s] PN_CHARS_BASE ::= [A-Z] | [a-z] | [#x00C0-#x00D6] | [#x00D8-#x00F6] | [#x00F8-#x02FF] | [#x0370-#x037D] | [#x037F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
>>> [164s] PN_CHARS_U ::= PN_CHARS_BASE | '_'
>>> [166s] PN_CHARS ::= PN_CHARS_U | '-' | [0-9] | #x00B7 | [#x0300-#x036F] | [#x203F-#x2040]
>>> [167s] PN_PREFIX ::= PN_CHARS_BASE ((PN_CHARS | '.')* PN_CHARS)?
>>> [168s] PN_LOCAL ::= (PN_CHARS_U | ':' | [0-9] | PLX) ((PN_CHARS | '.' | ':' | PLX)* (PN_CHARS | ':' | PLX))?
>>> [169s] PLX ::= PERCENT | PN_LOCAL_ESC
>>> [170s] PERCENT ::= '%' HEX HEX
>>> [171s] HEX ::= [0-9] | [A-F] | [a-f]
>>> [172s] PN_LOCAL_ESC ::= '\\' ('_' | '~' | '.' | '-' | '!' | '$' | '&' | "'" | '(' | ')' | '*' | '+' | ',' | ';' | '=' | '/' | '?' | '#' | '@' | '%')
>>>
>>> @pass: [ \t\r\n]+ | '#' [^\r\n]*
>>>
>>>
>>> --
>>> -ericP
>>>
>>
>
> --
> -ericP
Received on Monday, 8 July 2013 04:33:31 UTC