Hi Sebastian, only to have some clarification :
2013/11/19 Sebastian Schaffert <[email protected]> > Hi Alessandro, > > this is a change we have in mind already for a long time, but we need to > be careful about the implications because it transforms LDPath into a > tree matching language Are you referring to the fact that from a language that returns a single node ( or set of nodes) we are transforming LDPath in a language that returns a sub-tree ( or a set of sub-trees ) ? > with all consequences (essentially this is then a > unification problem with variable binding). Reflecting on this, in the example syntax proposed, after selected the parent node ( with the LDPath expression before the parenthes { ), we have simply to apply the relative path for each variable, to bind the variable with the value. Practically we already have the binding for the variables, we have only to follow the path and execute the substitution. Is it still a unification problem ? Probably yes, but it's simplified correct ? > Actually my PhD 10 years ago > was exactly on that issue (we called it "simulation unification" then, > referring to the two algorithms we used as a foundation - graph > simulation and term unification)... ;-) > More details regarding this part ? > > I'll still think about it a bit, but I think there is a clear > opportunity for a good improvement here. > > Greetings, > Cheers > > Sebastian > > Am Dienstag, den 19.11.2013, 09:39 +0000 schrieb Alessandro Benedetti: > > Hi guys, > > following a discussion related to Apache Stanbol, I want to propose a new > > feature in LDPath query language, to obtain nested queries and nested > > objects extracting properties from a specific resource. > > > > An example of syntax can be : > > > > city= ../foaf:based_near { name=gn:name, population=gn:population, state= > > gn:state } > > > > Accessing to a RDF resource and then, for each resource satisfying the > > parent expression, retrieve an object. > > The Object properties should be the ones listed in the provided map, with > > the specific aliases. > > > > In the previous example , for example having these three resources that > > satisfy the first expression ( city= ../foaf:based_near ) , we want to > > retrieve these 3 objects of type city ( the population numbers are fancy > > number): > > > > city1{ name= Paris, population= 13.000.000, state=France} > > city2{ name= Rome, population= 6.000.000, state=Italy} > > city3{ name= London, population= 16.000.000, state=England} > > > > The scope of this improvement is to provide the possibility of extract > > array of objects with custom properties from the resources of our data > set. > > > > -- > > -------------------------- > > > > Benedetti Alessandro > > Visiting card : http://about.me/alessandro_benedetti > > > > "Tyger, tyger burning bright > > In the forests of the night, > > What immortal hand or eye > > Could frame thy fearful symmetry?" > > > > William Blake - Songs of Experience -1794 England > > > > > > > > > -- -------------------------- Benedetti Alessandro Visiting card : http://about.me/alessandro_benedetti "Tyger, tyger burning bright In the forests of the night, What immortal hand or eye Could frame thy fearful symmetry?" William Blake - Songs of Experience -1794 England
