rdf-ex/lib/rdf/dataset.ex
2022-05-14 23:03:14 +02:00

920 lines
28 KiB
Elixir

defmodule RDF.Dataset do
@moduledoc """
A set of `RDF.Graph`s.
It may have multiple named graphs and at most one unnamed ("default") graph.
`RDF.Dataset` implements:
- Elixir's `Access` behaviour
- Elixir's `Enumerable` protocol
- Elixir's `Inspect` protocol
- the `RDF.Data` protocol
"""
defstruct name: nil, graphs: %{}
@behaviour Access
alias RDF.{Graph, Description, IRI, Statement, PrefixMap, PropertyMap}
import RDF.Statement, only: [coerce_subject: 1, coerce_graph_name: 1]
import RDF.Utils
@type graph_name :: IRI.t() | nil
@type t :: %__MODULE__{
name: graph_name,
graphs: %{graph_name => Graph.t()}
}
@type input :: Graph.input() | t
@type update_graph_fun :: (Graph.t() -> {Graph.t(), input} | :pop)
@doc """
Creates an empty unnamed `RDF.Dataset`.
"""
@spec new :: t
def new, do: %__MODULE__{}
@doc """
Creates an `RDF.Dataset`.
If a keyword list is given an empty dataset is created.
Otherwise an unnamed dataset initialized with the given data is created.
See `new/2` for available arguments and the different ways to provide data.
## Examples
RDF.Dataset.new(name: EX.GraphName)
RDF.Dataset.new(init: {EX.S, EX.p, EX.O})
RDF.Dataset.new({EX.S, EX.p, EX.O})
"""
@spec new(input | keyword) :: t
def new(data_or_opts)
def new(data_or_opts) when is_list(data_or_opts) and length(data_or_opts) != 0 do
if Keyword.keyword?(data_or_opts) do
{data, options} = Keyword.pop(data_or_opts, :init)
new(data, options)
else
new(data_or_opts, [])
end
end
def new(data), do: new(data, [])
@doc """
Creates an `RDF.Dataset` initialized with data.
The initial RDF triples can be provided in any form accepted by `add/3`.
Available options:
- `name`: the name of the dataset to be created
- `init`: some data with which the dataset should be initialized; the data can be
provided in any form accepted by `add/3` and above that also with a function returning
the initialization data in any of these forms
"""
@spec new(input, keyword) :: t
def new(data, opts)
def new(%__MODULE__{} = graph, opts) do
%__MODULE__{graph | name: opts |> Keyword.get(:name) |> coerce_graph_name()}
end
def new(data, opts) do
%__MODULE__{}
|> new(opts)
|> init(data, opts)
end
defp init(dataset, nil, _), do: dataset
defp init(dataset, fun, opts) when is_function(fun), do: add(dataset, fun.(), opts)
defp init(dataset, data, opts), do: add(dataset, data, opts)
@doc """
Returns the dataset name IRI of `dataset`.
"""
@spec name(t) :: Statement.graph_name()
def name(%__MODULE__{} = dataset), do: dataset.name
@doc """
Changes the dataset name of `dataset`.
"""
@spec change_name(t, Statement.coercible_graph_name()) :: t
def change_name(%__MODULE__{} = dataset, new_name) do
%__MODULE__{dataset | name: coerce_graph_name(new_name)}
end
defp destination_graph(opts, default \\ nil) do
opts
|> Keyword.get(:graph, default)
|> coerce_graph_name()
end
@doc """
Adds triples and quads to a `RDF.Dataset`.
The triples can be provided in any form accepted by `add/2`.
- as a single statement tuple
- an `RDF.Description`
- an `RDF.Graph`
- an `RDF.Dataset`
- or a list with any combination of the former
The `graph` option allows to set a different destination graph to which the
statements should be added, ignoring the graph context of given quads or the
name of given graphs in `input`.
Note: When the statements to be added are given as another `RDF.Dataset` and
a destination graph is set with the `graph` option, the descriptions of the
subjects in the different graphs are aggregated.
"""
@spec add(t, input, keyword) :: t
def add(dataset, input, opts \\ [])
def add(%__MODULE__{} = dataset, {_, _, _, graph} = quad, opts),
do: do_add(dataset, destination_graph(opts, graph), quad, opts)
def add(%__MODULE__{} = dataset, %Description{} = description, opts),
do: do_add(dataset, destination_graph(opts), description, opts)
def add(%__MODULE__{} = dataset, %Graph{} = graph, opts),
do: do_add(dataset, destination_graph(opts, graph.name), graph, opts)
def add(%__MODULE__{} = dataset, %__MODULE__{} = other_dataset, opts) do
other_dataset
|> graphs()
|> Enum.reduce(dataset, &add(&2, &1, opts))
end
def add(dataset, input, opts)
when is_list(input) or (is_map(input) and not is_struct(input)) do
Enum.reduce(input, dataset, &add(&2, &1, opts))
end
def add(%__MODULE__{} = dataset, input, opts),
do: do_add(dataset, destination_graph(opts), input, opts)
defp do_add(dataset, graph_name, input, opts) do
%__MODULE__{
dataset
| graphs:
lazy_map_update(
dataset.graphs,
graph_name,
# when new:
fn -> Graph.new(input, Keyword.put(opts, :name, graph_name)) end,
# when update:
fn graph -> Graph.add(graph, input, opts) end
)
}
end
@doc """
Adds statements to a `RDF.Dataset` overwriting existing statements with the subjects given in the `input` data.
The `graph` option allows to set a different destination graph to which the
statements should be added, ignoring the graph context of given quads or the
name of given graphs in `input`.
Note: When the statements to be added are given as another `RDF.Dataset` and
a destination graph is set with the `graph` option, the descriptions of the
subjects in the different graphs are aggregated.
## Examples
iex> dataset = RDF.Dataset.new({EX.S, EX.P1, EX.O1})
...> RDF.Dataset.put(dataset, {EX.S, EX.P2, EX.O2})
RDF.Dataset.new({EX.S, EX.P2, EX.O2})
iex> RDF.Dataset.put(dataset, {EX.S2, EX.P2, EX.O2})
RDF.Dataset.new([{EX.S, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
"""
@spec put(t, input, keyword) :: t
def put(dataset, input, opts \\ [])
def put(%__MODULE__{} = dataset, %__MODULE__{} = input, opts) do
%__MODULE__{
dataset
| graphs:
Enum.reduce(
input.graphs,
dataset.graphs,
fn {graph_name, graph}, graphs ->
Map.update(
graphs,
graph_name,
graph,
fn current -> Graph.put(current, graph, opts) end
)
end
)
}
end
def put(%__MODULE__{} = dataset, input, opts) do
put(dataset, new() |> add(input, opts), opts)
end
@doc """
Adds statements to a `RDF.Dataset` and overwrites all existing statements with the same subject-predicate combinations given in the `input` data.
The `graph` option allows to set a different destination graph to which the
statements should be added, ignoring the graph context of given quads or the
name of given graphs in `input`.
Note: When the statements to be added are given as another `RDF.Dataset` and
a destination graph is set with the `graph` option, the descriptions of the
subjects in the different graphs are aggregated.
## Examples
iex> dataset = RDF.Dataset.new({EX.S, EX.P1, EX.O1})
...> RDF.Dataset.put_properties(dataset, {EX.S, EX.P1, EX.O2})
RDF.Dataset.new({EX.S, EX.P1, EX.O2})
iex> RDF.Dataset.put_properties(dataset, {EX.S, EX.P2, EX.O2})
RDF.Dataset.new([{EX.S, EX.P1, EX.O1}, {EX.S, EX.P2, EX.O2}])
iex> RDF.Dataset.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
...> |> RDF.Dataset.put_properties([{EX.S1, EX.P2, EX.O3}, {EX.S2, EX.P2, EX.O3}])
RDF.Dataset.new([{EX.S1, EX.P1, EX.O1}, {EX.S1, EX.P2, EX.O3}, {EX.S2, EX.P2, EX.O3}])
"""
@spec put_properties(t, input, keyword) :: t
def put_properties(dataset, input, opts \\ [])
def put_properties(%__MODULE__{} = dataset, %__MODULE__{} = input, opts) do
%__MODULE__{
dataset
| graphs:
Enum.reduce(
input.graphs,
dataset.graphs,
fn {graph_name, graph}, graphs ->
Map.update(
graphs,
graph_name,
graph,
fn current -> Graph.put_properties(current, graph, opts) end
)
end
)
}
end
def put_properties(%__MODULE__{} = dataset, input, opts) do
put_properties(dataset, new() |> add(input, opts), opts)
end
@doc """
Deletes statements from a `RDF.Dataset`.
The `graph` option allows to set a different destination graph from which the
statements should be deleted, ignoring the graph context of given quads or the
name of given graphs.
Note: When the statements to be deleted are given as another `RDF.Dataset`,
the dataset name must not match dataset name of the dataset from which the statements
are deleted. If you want to delete only datasets with matching names, you can
use `RDF.Data.delete/2`.
"""
@spec delete(t, input, keyword) :: t
def delete(dataset, input, opts \\ [])
def delete(%__MODULE__{} = dataset, {_, _, _, graph} = quad, opts),
do: do_delete(dataset, destination_graph(opts, graph), quad, opts)
def delete(%__MODULE__{} = dataset, %Description{} = description, opts),
do: do_delete(dataset, destination_graph(opts), description, opts)
def delete(%__MODULE__{} = dataset, %Graph{} = graph, opts),
do: do_delete(dataset, destination_graph(opts, graph.name), graph, opts)
def delete(%__MODULE__{} = dataset, %__MODULE__{} = other_dataset, opts) do
other_dataset
|> graphs()
|> Enum.reduce(dataset, &delete(&2, &1, opts))
end
def delete(dataset, input, opts)
when is_list(input) or (is_map(input) and not is_struct(input)) do
Enum.reduce(input, dataset, &delete(&2, &1, opts))
end
def delete(%__MODULE__{} = dataset, input, opts) when not is_struct(input),
do: do_delete(dataset, destination_graph(opts), input, opts)
defp do_delete(dataset, graph_name, input, opts) do
if existing_graph = dataset.graphs[graph_name] do
new_graph = Graph.delete(existing_graph, input, opts)
%__MODULE__{
dataset
| graphs:
if Graph.empty?(new_graph) do
Map.delete(dataset.graphs, graph_name)
else
Map.put(dataset.graphs, graph_name, new_graph)
end
}
else
dataset
end
end
@doc """
Deletes the given graph.
"""
@spec delete_graph(t, Statement.graph_name() | [Statement.graph_name()] | nil) :: t
def delete_graph(graph, graph_names)
def delete_graph(%__MODULE__{} = dataset, graph_names) when is_list(graph_names) do
Enum.reduce(graph_names, dataset, &delete_graph(&2, &1))
end
def delete_graph(%__MODULE__{} = dataset, graph_name) do
%__MODULE__{dataset | graphs: Map.delete(dataset.graphs, coerce_graph_name(graph_name))}
end
@doc """
Deletes the default graph.
"""
@spec delete_default_graph(t) :: t
def delete_default_graph(%__MODULE__{} = graph),
do: delete_graph(graph, nil)
@doc """
Fetches the `RDF.Graph` with the given name.
When a graph with the given name can not be found can not be found `:error` is returned.
## Examples
iex> dataset = RDF.Dataset.new([{EX.S1, EX.P1, EX.O1, EX.Graph}, {EX.S2, EX.P2, EX.O2}])
...> RDF.Dataset.fetch(dataset, EX.Graph)
{:ok, RDF.Graph.new({EX.S1, EX.P1, EX.O1}, name: EX.Graph)}
iex> RDF.Dataset.fetch(dataset, nil)
{:ok, RDF.Graph.new({EX.S2, EX.P2, EX.O2})}
iex> RDF.Dataset.fetch(dataset, EX.Foo)
:error
"""
@impl Access
@spec fetch(t, Statement.graph_name() | nil) :: {:ok, Graph.t()} | :error
def fetch(%__MODULE__{} = dataset, graph_name) do
Access.fetch(dataset.graphs, coerce_graph_name(graph_name))
end
@doc """
Fetches the `RDF.Graph` with the given name.
When a graph with the given name can not be found can not be found the optionally
given default value or `nil` is returned
## Examples
iex> dataset = RDF.Dataset.new([{EX.S1, EX.P1, EX.O1, EX.Graph}, {EX.S2, EX.P2, EX.O2}])
...> RDF.Dataset.get(dataset, EX.Graph)
RDF.Graph.new({EX.S1, EX.P1, EX.O1}, name: EX.Graph)
iex> RDF.Dataset.get(dataset, nil)
RDF.Graph.new({EX.S2, EX.P2, EX.O2})
iex> RDF.Dataset.get(dataset, EX.Foo)
nil
iex> RDF.Dataset.get(dataset, EX.Foo, :bar)
:bar
"""
@spec get(t, Statement.graph_name() | nil, Graph.t() | nil) :: Graph.t() | nil
def get(%__MODULE__{} = dataset, graph_name, default \\ nil) do
case fetch(dataset, graph_name) do
{:ok, value} -> value
:error -> default
end
end
@doc """
The graph with given name.
"""
@spec graph(t, Statement.graph_name() | nil) :: Graph.t()
def graph(%__MODULE__{} = dataset, graph_name) do
Map.get(dataset.graphs, coerce_graph_name(graph_name))
end
@doc """
The default graph of a `RDF.Dataset`.
"""
@spec default_graph(t) :: Graph.t()
def default_graph(%__MODULE__{} = dataset) do
Map.get(dataset.graphs, nil, Graph.new())
end
@doc """
The set of all graphs.
"""
@spec graphs(t) :: [Graph.t()]
def graphs(%__MODULE__{} = dataset), do: Map.values(dataset.graphs)
@doc """
Gets and updates the graph with the given name, in a single pass.
Invokes the passed function on the `RDF.Graph` with the given name;
this function should return either `{graph_to_return, new_graph}` or `:pop`.
If the passed function returns `{graph_to_return, new_graph}`, the
return value of `get_and_update` is `{graph_to_return, new_dataset}` where
`new_dataset` is the input `Dataset` updated with `new_graph` for
the given name.
If the passed function returns `:pop` the graph with the given name is
removed and a `{removed_graph, new_dataset}` tuple gets returned.
## Examples
iex> dataset = RDF.Dataset.new({EX.S, EX.P, EX.O, EX.Graph})
...> RDF.Dataset.get_and_update(dataset, EX.Graph, fn current_graph ->
...> {current_graph, {EX.S, EX.P, EX.NEW}}
...> end)
{RDF.Graph.new({EX.S, EX.P, EX.O}, name: EX.Graph), RDF.Dataset.new({EX.S, EX.P, EX.NEW, EX.Graph})}
"""
@impl Access
@spec get_and_update(t, Statement.graph_name() | nil, update_graph_fun) :: {Graph.t(), input}
def get_and_update(%__MODULE__{} = dataset, graph_name, fun) do
graph_context = coerce_graph_name(graph_name)
case fun.(get(dataset, graph_context)) do
{old_graph, new_graph} ->
{old_graph, put(dataset, new_graph, graph: graph_context)}
:pop ->
pop(dataset, graph_context)
other ->
raise "the given function must return a two-element tuple or :pop, got: #{inspect(other)}"
end
end
@doc """
Pops an arbitrary statement from a `RDF.Dataset`.
"""
@spec pop(t) :: {Statement.t() | nil, t}
def pop(dataset)
def pop(%__MODULE__{graphs: graphs} = dataset)
when graphs == %{},
do: {nil, dataset}
def pop(%__MODULE__{graphs: graphs} = dataset) do
# TODO: Find a faster way ...
[{graph_name, graph}] = Enum.take(graphs, 1)
{{s, p, o}, popped_graph} = Graph.pop(graph)
popped =
if Graph.empty?(popped_graph),
do: graphs |> Map.delete(graph_name),
else: graphs |> Map.put(graph_name, popped_graph)
{
{s, p, o, graph_name},
%__MODULE__{dataset | graphs: popped}
}
end
@doc """
Pops the graph with the given name.
When a graph with given name can not be found the optionally given default value
or `nil` is returned.
## Examples
iex> dataset = RDF.Dataset.new([
...> {EX.S1, EX.P1, EX.O1, EX.Graph},
...> {EX.S2, EX.P2, EX.O2}])
...> RDF.Dataset.pop(dataset, EX.Graph)
{RDF.Graph.new({EX.S1, EX.P1, EX.O1}, name: EX.Graph), RDF.Dataset.new({EX.S2, EX.P2, EX.O2})}
iex> RDF.Dataset.pop(dataset, EX.Foo)
{nil, dataset}
"""
@impl Access
@spec pop(t, Statement.coercible_graph_name()) :: {Statement.t() | nil, t}
def pop(%__MODULE__{} = dataset, graph_name) do
case Access.pop(dataset.graphs, coerce_graph_name(graph_name)) do
{nil, _} ->
{nil, dataset}
{graph, new_graphs} ->
{graph, %__MODULE__{dataset | graphs: new_graphs}}
end
end
@doc """
The number of graphs within a `RDF.Dataset`.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3, EX.Graph}])
...> |> RDF.Dataset.graph_count()
2
"""
@spec graph_count(t) :: non_neg_integer
def graph_count(%__MODULE__{} = dataset) do
map_size(dataset.graphs)
end
@doc """
The number of statements within a `RDF.Dataset`.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}]) |>
...> RDF.Dataset.statement_count
3
"""
@spec statement_count(t) :: non_neg_integer
def statement_count(%__MODULE__{} = dataset) do
Enum.reduce(dataset.graphs, 0, fn {_, graph}, count ->
count + Graph.triple_count(graph)
end)
end
@doc """
The set of all subjects used in the statement within all graphs of a `RDF.Dataset`.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}]) |>
...> RDF.Dataset.subjects
MapSet.new([RDF.iri(EX.S1), RDF.iri(EX.S2)])
"""
def subjects(%__MODULE__{} = dataset) do
Enum.reduce(dataset.graphs, MapSet.new(), fn {_, graph}, subjects ->
MapSet.union(subjects, Graph.subjects(graph))
end)
end
@doc """
The set of all properties used in the predicates within all graphs of a `RDF.Dataset`.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}]) |>
...> RDF.Dataset.predicates
MapSet.new([EX.p1, EX.p2])
"""
def predicates(%__MODULE__{} = dataset) do
Enum.reduce(dataset.graphs, MapSet.new(), fn {_, graph}, predicates ->
MapSet.union(predicates, Graph.predicates(graph))
end)
end
@doc """
The set of all resources used in the objects within a `RDF.Dataset`.
Note: This function does collect only IRIs and BlankNodes, not Literals.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p2, EX.O2, EX.Graph},
...> {EX.S3, EX.p1, EX.O2},
...> {EX.S4, EX.p2, RDF.bnode(:bnode)},
...> {EX.S5, EX.p3, "foo"}
...> ]) |> RDF.Dataset.objects
MapSet.new([RDF.iri(EX.O1), RDF.iri(EX.O2), RDF.bnode(:bnode)])
"""
def objects(%__MODULE__{} = dataset) do
Enum.reduce(dataset.graphs, MapSet.new(), fn {_, graph}, objects ->
MapSet.union(objects, Graph.objects(graph))
end)
end
@doc """
The set of all resources used within a `RDF.Dataset`.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p1, EX.O2, EX.Graph},
...> {EX.S2, EX.p2, RDF.bnode(:bnode)},
...> {EX.S3, EX.p1, "foo"}
...> ]) |> RDF.Dataset.resources
MapSet.new([RDF.iri(EX.S1), RDF.iri(EX.S2), RDF.iri(EX.S3),
RDF.iri(EX.O1), RDF.iri(EX.O2), RDF.bnode(:bnode), EX.p1, EX.p2])
"""
def resources(%__MODULE__{} = dataset) do
Enum.reduce(dataset.graphs, MapSet.new(), fn {_, graph}, resources ->
MapSet.union(resources, Graph.resources(graph))
end)
end
@doc """
All statements within all graphs of a `RDF.Dataset`.
When the optional `:filter_star` flag is set to `true` RDF-star statements with
a triple as subject or object will be filtered. The default value is `false`.
## Examples
iex> RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}]) |>
...> RDF.Dataset.statements
[{RDF.iri(EX.S1), RDF.iri(EX.p2), RDF.iri(EX.O3)},
{RDF.iri(EX.S2), RDF.iri(EX.p2), RDF.iri(EX.O2)},
{RDF.iri(EX.S1), RDF.iri(EX.p1), RDF.iri(EX.O1), RDF.iri(EX.Graph)}]
"""
@spec statements(t, keyword) :: [Statement.t()]
def statements(%__MODULE__{} = dataset, opts \\ []) do
Enum.flat_map(dataset.graphs, fn
{nil, graph} ->
Graph.triples(graph, opts)
{name, graph} ->
graph |> Graph.triples(opts) |> Enum.map(fn {s, p, o} -> {s, p, o, name} end)
end)
end
@doc """
Returns if the given `dataset` is empty.
Note: You should always prefer this over the use of `Enum.empty?/1` as it is significantly faster.
"""
@spec empty?(t) :: boolean
def empty?(%__MODULE__{} = dataset) do
Enum.empty?(dataset.graphs) or dataset |> graphs() |> Enum.all?(&Graph.empty?/1)
end
@doc """
Checks if the given `input` statements exist within `dataset`.
The `graph` option allows to set a different destination graph in which the
statements should be checked, ignoring the graph context of given quads or the
name of given graphs.
## Examples
iex> dataset = RDF.Dataset.new([
...> {EX.S1, EX.p1, EX.O1, EX.Graph},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}])
...> RDF.Dataset.include?(dataset, {EX.S1, EX.p1, EX.O1, EX.Graph})
true
"""
@spec include?(t, input, keyword) :: boolean
def include?(dataset, input, opts \\ [])
def include?(%__MODULE__{} = dataset, {_, _, _, graph} = quad, opts),
do: do_include?(dataset, destination_graph(opts, graph), quad, opts)
def include?(%__MODULE__{} = dataset, %Description{} = description, opts),
do: do_include?(dataset, destination_graph(opts), description, opts)
def include?(%__MODULE__{} = dataset, %Graph{} = graph, opts),
do: do_include?(dataset, destination_graph(opts, graph.name), graph, opts)
def include?(%__MODULE__{} = dataset, %__MODULE__{} = other_dataset, opts) do
other_dataset
|> graphs()
|> Enum.all?(&include?(dataset, &1, opts))
end
def include?(dataset, input, opts)
when is_list(input) or (is_map(input) and not is_struct(input)) do
Enum.all?(input, &include?(dataset, &1, opts))
end
def include?(dataset, input, opts) when not is_struct(input),
do: do_include?(dataset, destination_graph(opts), input, opts)
defp do_include?(%__MODULE__{} = dataset, graph_name, input, opts) do
if graph = dataset.graphs[graph_name] do
Graph.include?(graph, input, opts)
else
false
end
end
@doc """
Checks if a graph of a `RDF.Dataset` contains statements about the given resource.
## Examples
iex> RDF.Dataset.new([{EX.S1, EX.p1, EX.O1}]) |> RDF.Dataset.describes?(EX.S1)
true
iex> RDF.Dataset.new([{EX.S1, EX.p1, EX.O1}]) |> RDF.Dataset.describes?(EX.S2)
false
"""
@spec describes?(t, Statement.t(), Statement.coercible_graph_name() | nil) :: boolean
def describes?(%__MODULE__{} = dataset, subject, graph_context \\ nil) do
if graph = dataset.graphs[coerce_graph_name(graph_context)] do
Graph.describes?(graph, subject)
else
false
end
end
@doc """
Returns the names of all graphs of a `RDF.Dataset` containing statements about the given subject.
## Examples
iex> dataset = RDF.Dataset.new([
...> {EX.S1, EX.p, EX.O},
...> {EX.S2, EX.p, EX.O},
...> {EX.S1, EX.p, EX.O, EX.Graph1},
...> {EX.S2, EX.p, EX.O, EX.Graph2}])
...> RDF.Dataset.who_describes(dataset, EX.S1)
[nil, RDF.iri(EX.Graph1)]
"""
@spec who_describes(t, Statement.coercible_subject()) :: [Graph.t()]
def who_describes(%__MODULE__{} = dataset, subject) do
subject = coerce_subject(subject)
dataset.graphs
|> Map.values()
|> Stream.filter(&Graph.describes?(&1, subject))
|> Enum.map(& &1.name)
end
@doc """
Returns a nested map of the native Elixir values of a `RDF.Dataset`.
When a `:context` option is given with a `RDF.PropertyMap`, predicates will
be mapped to the terms defined in the `RDF.PropertyMap`, if present.
## Examples
iex> [
...> {~I<http://example.com/S>, ~I<http://example.com/p>, ~L"Foo", ~I<http://example.com/Graph>},
...> {~I<http://example.com/S>, ~I<http://example.com/p>, RDF.XSD.integer(42), }
...> ]
...> |> RDF.Dataset.new()
...> |> RDF.Dataset.values()
%{
"http://example.com/Graph" => %{
"http://example.com/S" => %{"http://example.com/p" => ["Foo"]}
},
nil => %{
"http://example.com/S" => %{"http://example.com/p" => [42]}
}
}
"""
@spec values(t, keyword) :: map
def values(%__MODULE__{} = dataset, opts \\ []) do
if property_map = PropertyMap.from_opts(opts) do
map(dataset, Statement.default_property_mapping(property_map))
else
map(dataset, &Statement.default_term_mapping/1)
end
end
@doc """
Returns a nested map of a `RDF.Dataset` where each element from its quads is mapped with the given function.
The function `fun` will receive a tuple `{statement_position, rdf_term}` where
`statement_position` is one of the atoms `:subject`, `:predicate`, `:object` or
`:graph_name` while `rdf_term` is the RDF term to be mapped. When the given function
returns `nil` this will be interpreted as an error and will become the overhaul
result of the `map/2` call.
## Examples
iex> [
...> {~I<http://example.com/S>, ~I<http://example.com/p>, ~L"Foo", ~I<http://example.com/Graph>},
...> {~I<http://example.com/S>, ~I<http://example.com/p>, RDF.XSD.integer(42), }
...> ]
...> |> RDF.Dataset.new()
...> |> RDF.Dataset.map(fn
...> {:graph_name, graph_name} ->
...> graph_name
...> {:predicate, predicate} ->
...> predicate
...> |> to_string()
...> |> String.split("/")
...> |> List.last()
...> |> String.to_atom()
...> {_, term} ->
...> RDF.Term.value(term)
...> end)
%{
~I<http://example.com/Graph> => %{
"http://example.com/S" => %{p: ["Foo"]}
},
nil => %{
"http://example.com/S" => %{p: [42]}
}
}
"""
@spec map(t, Statement.term_mapping()) :: map
def map(dataset, fun)
def map(%__MODULE__{} = dataset, fun) do
Map.new(dataset.graphs, fn {graph_name, graph} ->
{fun.({:graph_name, graph_name}), Graph.map(graph, fun)}
end)
end
@doc """
Checks if two `RDF.Dataset`s are equal.
Two `RDF.Dataset`s are considered to be equal if they contain the same triples
and have the same name.
"""
@spec equal?(t | any, t | any) :: boolean
def equal?(dataset1, dataset2)
def equal?(%__MODULE__{} = dataset1, %__MODULE__{} = dataset2) do
clear_metadata(dataset1) == clear_metadata(dataset2)
end
def equal?(_, _), do: false
@doc """
Returns the aggregated prefixes of all graphs of `dataset` as a `RDF.PrefixMap`.
"""
@spec prefixes(t) :: PrefixMap.t() | nil
def prefixes(%__MODULE__{} = dataset) do
dataset
|> RDF.Dataset.graphs()
|> Enum.reduce(RDF.PrefixMap.new(), fn graph, prefixes ->
if graph.prefixes do
RDF.PrefixMap.merge!(prefixes, graph.prefixes, :ignore)
else
prefixes
end
end)
end
defp clear_metadata(%__MODULE__{} = dataset) do
%__MODULE__{
dataset
| graphs:
Map.new(dataset.graphs, fn {name, graph} ->
{name, Graph.clear_metadata(graph)}
end)
}
end
defimpl Enumerable do
alias RDF.Dataset
def member?(dataset, statement), do: {:ok, Dataset.include?(dataset, statement)}
def count(dataset), do: {:ok, Dataset.statement_count(dataset)}
def slice(dataset) do
size = Dataset.statement_count(dataset)
{:ok, size, &Enumerable.List.slice(Dataset.statements(dataset), &1, &2, size)}
end
def reduce(dataset, acc, fun) do
dataset
|> Dataset.statements()
|> Enumerable.List.reduce(acc, fun)
end
end
defimpl Collectable do
alias RDF.Dataset
def into(original) do
collector_fun = fn
dataset, {:cont, list} when is_list(list) ->
Dataset.add(dataset, List.to_tuple(list))
dataset, {:cont, elem} ->
Dataset.add(dataset, elem)
dataset, :done ->
dataset
_dataset, :halt ->
:ok
end
{original, collector_fun}
end
end
end