rdf-ex/lib/rdf/data.ex

289 lines
9.5 KiB
Elixir

defprotocol RDF.Data do
@moduledoc """
An abstraction over the different data structures for collections of RDF statements.
"""
@doc """
Adds statements to a RDF data structure.
As opposed to the specific `add` functions on the RDF data structures, which
always return the same structure type than the first argument, `merge` might
result in another RDF data structure, eg. merging two `RDF.Description` with
different subjects results in a `RDF.Graph` or adding a quad to a `RDF.Graph`
with a different name than the graph context of the quad results in a
`RDF.Dataset`. But it is always guaranteed that the resulting structure has
a `RDF.Data` implementation.
"""
def merge(data, statements)
@doc """
Deletes statements from a RDF data structure.
As opposed to the `delete` functions on RDF data structures directly, this
function only deletes exactly matching structures.
TODO: rename this function to make the different semantics explicit
"""
def delete(data, statements)
@doc """
Deletes one statement from a RDF data structure and returns a tuple with deleted statement and the changed data structure.
"""
def pop(data)
@doc """
Checks if the given statement exists within a RDF data structure.
"""
def include?(data, statements)
@doc """
Checks if a RDF data structure contains statements about the given resource.
"""
def describes?(data, subject)
@doc """
Returns a `RDF.Description` of the given subject.
Note: On a `RDF.Dataset` this will return an aggregated `RDF.Description` with
the statements about this subject from all graphs.
"""
def description(data, subject)
@doc """
Returns all `RDF.Description`s within a RDF data structure.
Note: On a `RDF.Dataset` this will return aggregated `RDF.Description`s about
the same subject from all graphs.
"""
def descriptions(data)
@doc """
Returns the list of all statements of a RDF data structure.
"""
def statements(data)
@doc """
Returns the set of all resources which are subject of the statements of a RDF data structure.
"""
def subjects(data)
@doc """
Returns the set of all properties used within the statements of RDF data structure.
"""
def predicates(data)
@doc """
Returns the set of all resources used in the objects within the statements of a RDF data structure.
"""
def objects(data)
@doc """
Returns the set of all resources used within the statements of a RDF data structure
"""
def resources(data)
@doc """
Returns the count of all resources which are subject of the statements of a RDF data structure.
"""
def subject_count(data)
@doc """
Returns the count of all statements of a RDF data structure.
"""
def statement_count(data)
@doc """
Returns a nested map of the native Elixir values of a RDF data structure.
"""
def values(data)
@doc """
Returns a nested map of the native Elixir values of a RDF data structure with values mapped with the given function.
"""
def values(data, mapping)
end
defimpl RDF.Data, for: RDF.Description do
def merge(%RDF.Description{subject: subject} = description, {s, _, _} = triple) do
with ^subject <- RDF.Statement.coerce_subject(s) do
RDF.Description.add(description, triple)
else
_ ->
RDF.Graph.new(description)
|> RDF.Graph.add(triple)
end
end
def merge(description, {_, _, _, _} = quad),
do: RDF.Dataset.new(description) |> RDF.Dataset.add(quad)
def merge(%RDF.Description{subject: subject} = description,
%RDF.Description{subject: other_subject} = other_description)
when other_subject == subject,
do: RDF.Description.add(description, other_description)
def merge(description, %RDF.Description{} = other_description),
do: RDF.Graph.new(description) |> RDF.Graph.add(other_description)
def merge(description, %RDF.Graph{} = graph),
do: RDF.Data.merge(graph, description)
def merge(description, %RDF.Dataset{} = dataset),
do: RDF.Data.merge(dataset, description)
def delete(%RDF.Description{subject: subject} = description,
%RDF.Description{subject: other_subject})
when subject != other_subject, do: description
def delete(description, statements), do: RDF.Description.delete(description, statements)
def pop(description), do: RDF.Description.pop(description)
def include?(description, statements),
do: RDF.Description.include?(description, statements)
def describes?(description, subject),
do: RDF.Description.describes?(description, subject)
def description(%RDF.Description{subject: subject} = description, s) do
with ^subject <- RDF.Statement.coerce_subject(s) do
description
else
_ -> RDF.Description.new(s)
end
end
def descriptions(description), do: [description]
def statements(description), do: RDF.Description.statements(description)
def subjects(%RDF.Description{subject: subject}), do: MapSet.new([subject])
def predicates(description), do: RDF.Description.predicates(description)
def objects(description), do: RDF.Description.objects(description)
def resources(%RDF.Description{subject: subject} = description),
do: RDF.Description.resources(description) |> MapSet.put(subject)
def subject_count(_), do: 1
def statement_count(description), do: RDF.Description.count(description)
def values(description), do: RDF.Description.values(description)
def values(description, mapping), do: RDF.Description.values(description, mapping)
end
defimpl RDF.Data, for: RDF.Graph do
def merge(%RDF.Graph{name: name} = graph, {_, _, _, graph_context} = quad) do
with ^name <- RDF.Statement.coerce_graph_name(graph_context) do
RDF.Graph.add(graph, quad)
else
_ ->
RDF.Dataset.new(graph)
|> RDF.Dataset.add(quad)
end
end
def merge(graph, {_, _, _} = triple),
do: RDF.Graph.add(graph, triple)
def merge(description, {_, _, _, _} = quad),
do: RDF.Dataset.new(description) |> RDF.Dataset.add(quad)
def merge(graph, %RDF.Description{} = description),
do: RDF.Graph.add(graph, description)
def merge(%RDF.Graph{name: name} = graph,
%RDF.Graph{name: other_name} = other_graph)
when other_name == name,
do: RDF.Graph.add(graph, other_graph)
def merge(graph, %RDF.Graph{} = other_graph),
do: RDF.Dataset.new(graph) |> RDF.Dataset.add(other_graph)
def merge(graph, %RDF.Dataset{} = dataset),
do: RDF.Data.merge(dataset, graph)
def delete(%RDF.Graph{name: name} = graph, %RDF.Graph{name: other_name})
when name != other_name, do: graph
def delete(graph, statements), do: RDF.Graph.delete(graph, statements)
def pop(graph), do: RDF.Graph.pop(graph)
def include?(graph, statements), do: RDF.Graph.include?(graph, statements)
def describes?(graph, subject),
do: RDF.Graph.describes?(graph, subject)
def description(graph, subject),
do: RDF.Graph.description(graph, subject) || RDF.Description.new(subject)
def descriptions(graph), do: RDF.Graph.descriptions(graph)
def statements(graph), do: RDF.Graph.statements(graph)
def subjects(graph), do: RDF.Graph.subjects(graph)
def predicates(graph), do: RDF.Graph.predicates(graph)
def objects(graph), do: RDF.Graph.objects(graph)
def resources(graph), do: RDF.Graph.resources(graph)
def subject_count(graph), do: RDF.Graph.subject_count(graph)
def statement_count(graph), do: RDF.Graph.triple_count(graph)
def values(graph), do: RDF.Graph.values(graph)
def values(graph, mapping), do: RDF.Graph.values(graph, mapping)
end
defimpl RDF.Data, for: RDF.Dataset do
def merge(dataset, {_, _, _} = triple),
do: RDF.Dataset.add(dataset, triple)
def merge(dataset, {_, _, _, _} = quad),
do: RDF.Dataset.add(dataset, quad)
def merge(dataset, %RDF.Description{} = description),
do: RDF.Dataset.add(dataset, description)
def merge(dataset, %RDF.Graph{} = graph),
do: RDF.Dataset.add(dataset, graph)
def merge(dataset, %RDF.Dataset{} = other_dataset),
do: RDF.Dataset.add(dataset, other_dataset)
def delete(%RDF.Dataset{name: name} = dataset, %RDF.Dataset{name: other_name})
when name != other_name, do: dataset
def delete(dataset, statements), do: RDF.Dataset.delete(dataset, statements)
def pop(dataset), do: RDF.Dataset.pop(dataset)
def include?(dataset, statements), do: RDF.Dataset.include?(dataset, statements)
def describes?(dataset, subject),
do: RDF.Dataset.who_describes(dataset, subject) != []
def description(dataset, subject) do
with subject = RDF.Statement.coerce_subject(subject) do
Enum.reduce RDF.Dataset.graphs(dataset), RDF.Description.new(subject), fn
%RDF.Graph{descriptions: %{^subject => graph_description}}, description ->
RDF.Description.add(description, graph_description)
_, description ->
description
end
end
end
def descriptions(dataset) do
dataset
|> subjects
|> Enum.map(&(description(dataset, &1)))
end
def statements(dataset), do: RDF.Dataset.statements(dataset)
def subjects(dataset), do: RDF.Dataset.subjects(dataset)
def predicates(dataset), do: RDF.Dataset.predicates(dataset)
def objects(dataset), do: RDF.Dataset.objects(dataset)
def resources(dataset), do: RDF.Dataset.resources(dataset)
def subject_count(dataset), do: dataset |> subjects |> Enum.count
def statement_count(dataset), do: RDF.Dataset.statement_count(dataset)
def values(dataset), do: RDF.Dataset.values(dataset)
def values(dataset, mapping), do: RDF.Dataset.values(dataset, mapping)
end