rdf-ex/lib/rdf/graph.ex
2021-03-06 02:38:20 +01:00

1133 lines
34 KiB
Elixir

defmodule RDF.Graph do
@moduledoc """
A set of RDF triples with an optional name.
`RDF.Graph` implements:
- Elixir's `Access` behaviour
- Elixir's `Enumerable` protocol
- Elixir's `Inspect` protocol
- the `RDF.Data` protocol
"""
defstruct name: nil, descriptions: %{}, prefixes: nil, base_iri: nil
@behaviour Access
import RDF.Statement, only: [coerce_subject: 1, coerce_graph_name: 1]
import RDF.Utils
alias RDF.{Description, IRI, PrefixMap, Statement, PropertyMap}
@type graph_description :: %{Statement.subject() => Description.t()}
@type t :: %__MODULE__{
name: IRI.t() | nil,
descriptions: graph_description,
prefixes: PrefixMap.t() | nil,
base_iri: IRI.t() | nil
}
@type input ::
Statement.coercible_t()
| {
Statement.coercible_subject(),
Description.input()
}
| Description.t()
| t
| %{
Statement.coercible_subject() => %{
Statement.coercible_predicate() =>
Statement.coercible_object() | [Statement.coercible_object()]
}
}
| list(input)
@type update_description_fun :: (Description.t() -> Description.t())
@type get_and_update_description_fun :: (Description.t() -> {Description.t(), input} | :pop)
@doc """
Creates an empty unnamed `RDF.Graph`.
"""
@spec new :: t
def new, do: %__MODULE__{}
@doc """
Creates an `RDF.Graph`.
If a keyword list with options is given an empty graph is created.
Otherwise an unnamed graph initialized with the given data is created.
See `new/2` for available arguments and the different ways to provide data.
## Examples
RDF.Graph.new(name: EX.GraphName)
RDF.Graph.new(init: {EX.S, EX.p, EX.O})
RDF.Graph.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.Graph` initialized with data.
The initial RDF triples can be provided
- as a single statement tuple
- a `RDF.Description`
- a `RDF.Graph`
- or a list with any combination of the former
Available options:
- `name`: the name of the graph to be created
- `prefixes`: some prefix mappings which should be stored alongside the graph
and will be used for example when serializing in a format with prefix support
- `base_iri`: a base IRI which should be stored alongside the graph
and will be used for example when serializing in a format with base IRI support
- `init`: some data with which the graph 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
## Examples
RDF.Graph.new({EX.S, EX.p, EX.O})
RDF.Graph.new({EX.S, EX.p, EX.O}, name: EX.GraphName)
RDF.Graph.new({EX.S, EX.p, [EX.O1, EX.O2]})
RDF.Graph.new([{EX.S1, EX.p1, EX.O1}, {EX.S2, EX.p2, EX.O2}])
RDF.Graph.new(RDF.Description.new(EX.S, EX.P, EX.O))
RDF.Graph.new([graph, description, triple])
RDF.Graph.new({EX.S, EX.p, EX.O}, name: EX.GraphName, base_iri: EX.base)
"""
@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()}
|> add_prefixes(Keyword.get(opts, :prefixes))
|> set_base_iri(Keyword.get(opts, :base_iri))
end
def new(data, opts) do
new()
|> new(opts)
|> init(data, opts)
end
defp init(graph, nil, _), do: graph
defp init(graph, fun, opts) when is_function(fun), do: add(graph, fun.(), opts)
defp init(graph, data, opts), do: add(graph, data, opts)
@doc """
Removes all triples from `graph`.
This function is useful for getting an empty graph based on the settings of
another graph, as this function keeps graph name, base IRI and default prefixes
as they are and just removes the triples.
"""
@spec clear(t) :: t
def clear(%__MODULE__{} = graph) do
%__MODULE__{graph | descriptions: %{}}
end
@doc """
Returns the graph name IRI of `graph`.
"""
@spec name(t) :: Statement.graph_name()
def name(%__MODULE__{} = graph), do: graph.name
@doc """
Changes the graph name of `graph`.
"""
@spec change_name(t, Statement.coercible_graph_name()) :: t
def change_name(%__MODULE__{} = graph, new_name) do
%__MODULE__{graph | name: coerce_graph_name(new_name)}
end
@doc """
Adds triples to a `RDF.Graph`.
The `input` can be provided
- as a single statement tuple
- a `RDF.Description`
- a `RDF.Graph`
- or a list with any combination of the former
When the statements to be added are given as another `RDF.Graph`,
the graph name must not match graph name of the graph to which the statements
are added. As opposed to that, `RDF.Data.merge/2` will produce a `RDF.Dataset`
containing both graphs.
Also when the statements to be added are given as another `RDF.Graph`, the
prefixes of this graph will be added. In case of conflicting prefix mappings
the original prefix from `graph` will be kept.
"""
@spec add(t, input, keyword) :: t
def add(graph, input, opts \\ [])
def add(%__MODULE__{} = graph, {subject, predications}, opts),
do: do_add(graph, coerce_subject(subject), predications, opts)
def add(%__MODULE__{} = graph, {subject, _, _} = triple, opts),
do: do_add(graph, coerce_subject(subject), triple, opts)
def add(graph, {subject, predicate, object, _}, opts),
do: add(graph, {subject, predicate, object}, opts)
def add(%__MODULE__{} = graph, %Description{} = description, opts) do
if Description.count(description) > 0 do
do_add(graph, description.subject, description, opts)
else
graph
end
end
def add(graph, %__MODULE__{descriptions: descriptions, prefixes: prefixes}, opts) do
graph =
Enum.reduce(descriptions, graph, fn {_, description}, graph ->
add(graph, description, opts)
end)
if prefixes do
add_prefixes(graph, prefixes, :ignore)
else
graph
end
end
if Version.match?(System.version(), "~> 1.10") do
def add(graph, input, opts) when is_list(input) or (is_map(input) and not is_struct(input)) do
Enum.reduce(input, graph, &add(&2, &1, opts))
end
else
def add(_, %_{}, _), do: raise(ArgumentError, "structs are not allowed as input")
def add(graph, input, opts) when is_list(input) or is_map(input) do
Enum.reduce(input, graph, &add(&2, &1, opts))
end
end
defp do_add(%__MODULE__{descriptions: descriptions} = graph, subject, statements, opts) do
%__MODULE__{
graph
| descriptions:
lazy_map_update(
descriptions,
subject,
# when new: create and initialize description with statements
fn -> Description.new(subject, Keyword.put(opts, :init, statements)) end,
# when update: merge statements description
fn description -> Description.add(description, statements, opts) end
)
}
end
@doc """
Adds statements to a `RDF.Graph` overwriting existing statements with the subjects given in the `input` data.
When the statements to be added are given as another `RDF.Graph`, the prefixes
of this graph will be added. In case of conflicting prefix mappings the
original prefix from `graph` will be kept.
## Examples
iex> RDF.Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
...> |> RDF.Graph.put([{EX.S1, EX.P3, EX.O3}])
RDF.Graph.new([{EX.S1, EX.P3, EX.O3}, {EX.S2, EX.P2, EX.O2}])
"""
@spec put(t, input, keyword) :: t
def put(graph, input, opts \\ [])
def put(%__MODULE__{} = graph, %__MODULE__{} = input, _opts) do
graph = %__MODULE__{
graph
| descriptions:
Enum.reduce(
input.descriptions,
graph.descriptions,
fn {subject, description}, descriptions ->
Map.put(descriptions, subject, description)
end
)
}
if input.prefixes do
add_prefixes(graph, input.prefixes, :ignore)
else
graph
end
end
def put(%__MODULE__{} = graph, input, opts) do
put(graph, new() |> add(input, opts), opts)
end
@doc """
Adds statements to a `RDF.Graph` and overwrites all existing statements with the same subject-predicate combinations given in the `input` data.
When the statements to be added are given as another `RDF.Graph`, the prefixes
of this graph will be added. In case of conflicting prefix mappings the
original prefix from `graph` will be kept.
## Examples
iex> RDF.Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
...> |> RDF.Graph.put_properties([{EX.S1, EX.P2, EX.O3}, {EX.S2, EX.P2, EX.O3}])
RDF.Graph.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(graph, input, opts \\ [])
def put_properties(%__MODULE__{} = graph, %__MODULE__{} = input, opts) do
graph = %__MODULE__{
graph
| descriptions:
Enum.reduce(
input.descriptions,
graph.descriptions,
fn {subject, description}, descriptions ->
Map.update(
descriptions,
subject,
description,
fn current -> Description.put(current, description, opts) end
)
end
)
}
if input.prefixes do
add_prefixes(graph, input.prefixes, :ignore)
else
graph
end
end
def put_properties(%__MODULE__{} = graph, input, opts) do
put_properties(graph, new() |> add(input, opts), opts)
end
@doc """
Deletes statements from a `RDF.Graph`.
Note: When the statements to be deleted are given as another `RDF.Graph`,
the graph name must not match graph name of the graph from which the statements
are deleted. If you want to delete only graphs with matching names, you can
use `RDF.Data.delete/2`.
"""
@spec delete(t, input, keyword) :: t
def delete(graph, input, opts \\ [])
def delete(%__MODULE__{} = graph, {subject, _, _} = triple, opts),
do: do_delete(graph, coerce_subject(subject), triple, opts)
def delete(%__MODULE__{} = graph, {subject, predications}, opts),
do: do_delete(graph, coerce_subject(subject), predications, opts)
def delete(graph, {subject, predicate, object, _}, opts),
do: delete(graph, {subject, predicate, object}, opts)
def delete(%__MODULE__{} = graph, %Description{} = description, opts),
do: do_delete(graph, description.subject, description, opts)
def delete(%__MODULE__{} = graph, %__MODULE__{} = input, opts) do
Enum.reduce(input.descriptions, graph, fn {_, description}, graph ->
delete(graph, description, opts)
end)
end
if Version.match?(System.version(), "~> 1.10") do
def delete(%__MODULE__{} = graph, input, opts)
when is_list(input) or (is_map(input) and not is_struct(input)) do
Enum.reduce(input, graph, &delete(&2, &1, opts))
end
else
def delete(_, %_{}, _), do: raise(ArgumentError, "structs are not allowed as input")
def delete(%__MODULE__{} = graph, input, opts) when is_list(input) or is_map(input) do
Enum.reduce(input, graph, &delete(&2, &1, opts))
end
end
defp do_delete(%__MODULE__{descriptions: descriptions} = graph, subject, input, opts) do
if description = descriptions[subject] do
new_description = Description.delete(description, input, opts)
%__MODULE__{
graph
| descriptions:
if Enum.empty?(new_description) do
Map.delete(descriptions, subject)
else
Map.put(descriptions, subject, new_description)
end
}
else
graph
end
end
@doc """
Deletes all statements with the given `subjects`.
If `subjects` contains subjects that are not in `graph`, they're simply ignored.
"""
@spec delete_descriptions(
t,
Statement.coercible_subject() | [Statement.coercible_subject()]
) :: t
def delete_descriptions(graph, subjects)
def delete_descriptions(%__MODULE__{} = graph, subjects) when is_list(subjects) do
Enum.reduce(subjects, graph, &delete_descriptions(&2, &1))
end
def delete_descriptions(%__MODULE__{} = graph, subject) do
%__MODULE__{graph | descriptions: Map.delete(graph.descriptions, coerce_subject(subject))}
end
defdelegate delete_subjects(graph, subjects), to: __MODULE__, as: :delete_descriptions
@doc """
Updates the description of the `subject` in `graph` with the given function.
If `subject` is present in `graph` with `description` as description,
`fun` is invoked with argument `description` and its result is used as the new
description of `subject`. If `subject` is not present in `graph`,
`initial` is inserted as the description of `subject`. The initial value will
not be passed through the update function.
The initial value and the returned objects by the update function will be tried
te coerced to proper RDF descriptions before added. If the initial or returned
description is a `RDF.Description` with another subject, the respective
statements are added with `subject` as subject.
## Examples
iex> RDF.Graph.new({EX.S, EX.p, EX.O})
...> |> RDF.Graph.update(EX.S,
...> fn description -> Description.add(description, {EX.p, EX.O2})
...> end)
RDF.Graph.new([{EX.S, EX.p, EX.O}, {EX.S, EX.p, EX.O2}])
iex> RDF.Graph.new({EX.S, EX.p, EX.O})
...> |> RDF.Graph.update(EX.S,
...> fn _ -> Description.new(EX.S2, init: {EX.p2, EX.O2})
...> end)
RDF.Graph.new([{EX.S, EX.p2, EX.O2}])
iex> RDF.Graph.new()
...> |> RDF.Graph.update(EX.S, Description.new(EX.S, init: {EX.p, EX.O}),
...> fn description -> Description.add(description, {EX.p, EX.O2})
...> end)
RDF.Graph.new([{EX.S, EX.p, EX.O}])
"""
@spec update(
t,
Statement.coercible_subject(),
Description.input() | nil,
update_description_fun
) :: t
def update(%__MODULE__{} = graph, subject, initial \\ nil, fun) do
subject = coerce_subject(subject)
case get(graph, subject) do
nil ->
if initial do
add(graph, Description.new(subject, init: initial))
else
graph
end
description ->
description
|> fun.()
|> case do
nil ->
delete_descriptions(graph, subject)
new_description ->
graph
|> delete_descriptions(subject)
|> add(Description.new(subject, init: new_description))
end
end
end
@doc """
Fetches the description of the given subject.
When the subject can not be found `:error` is returned.
## Examples
iex> RDF.Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
...> |> RDF.Graph.fetch(EX.S1)
{:ok, RDF.Description.new(EX.S1, init: {EX.P1, EX.O1})}
iex> RDF.Graph.new() |> RDF.Graph.fetch(EX.foo)
:error
"""
@impl Access
@spec fetch(t, Statement.coercible_subject()) :: {:ok, Description.t()} | :error
def fetch(%__MODULE__{} = graph, subject) do
Access.fetch(graph.descriptions, coerce_subject(subject))
end
@doc """
Execute the given `query` against the given `graph`.
This is just a convenience delegator function to `RDF.Query.execute!/3` with
the first two arguments swapped so it can be used in a pipeline on a `RDF.Graph`.
See `RDF.Query.execute/3` and `RDF.Query.execute!/3` for more information and examples.
"""
def query(graph, query, opts \\ []) do
RDF.Query.execute!(query, graph, opts)
end
@doc """
Returns a `Stream` for the execution of the given `query` against the given `graph`.
This is just a convenience delegator function to `RDF.Query.stream!/3` with
the first two arguments swapped so it can be used in a pipeline on a `RDF.Graph`.
See `RDF.Query.stream/3` and `RDF.Query.stream!/3` for more information and examples.
"""
def query_stream(graph, query, opts \\ []) do
RDF.Query.stream!(query, graph, opts)
end
@doc """
Gets the description of the given subject.
When the subject can not be found the optionally given default value or `nil` is returned.
## Examples
iex> RDF.Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
...> |> RDF.Graph.get(EX.S1)
RDF.Description.new(EX.S1, init: {EX.P1, EX.O1})
iex> RDF.Graph.new() |> RDF.Graph.get(EX.Foo)
nil
iex> RDF.Graph.new() |> RDF.Graph.get(EX.Foo, :bar)
:bar
"""
@spec get(t, Statement.coercible_subject(), Description.t() | nil) :: Description.t() | nil
def get(%__MODULE__{} = graph, subject, default \\ nil) do
case fetch(graph, subject) do
{:ok, value} -> value
:error -> default
end
end
@doc """
The `RDF.Description` of the given subject.
"""
@spec description(t, Statement.coercible_subject()) :: Description.t() | nil
def description(%__MODULE__{} = graph, subject) do
Map.get(graph.descriptions, coerce_subject(subject))
end
@doc """
All `RDF.Description`s within a `RDF.Graph`.
"""
@spec descriptions(t) :: [Description.t()]
def descriptions(%__MODULE__{} = graph) do
Map.values(graph.descriptions)
end
@doc """
Gets and updates the description of the given subject, in a single pass.
Invokes the passed function on the `RDF.Description` of the given subject;
this function should return either `{description_to_return, new_description}` or `:pop`.
If the passed function returns `{description_to_return, new_description}`, the
return value of `get_and_update` is `{description_to_return, new_graph}` where
`new_graph` is the input `Graph` updated with `new_description` for
the given subject.
If the passed function returns `:pop` the description for the given subject is
removed and a `{removed_description, new_graph}` tuple gets returned.
## Examples
iex> RDF.Graph.new({EX.S, EX.P, EX.O})
...> |> RDF.Graph.get_and_update(EX.S, fn current_description ->
...> {current_description, {EX.P, EX.NEW}}
...> end)
{RDF.Description.new(EX.S, init: {EX.P, EX.O}), RDF.Graph.new({EX.S, EX.P, EX.NEW})}
"""
@impl Access
@spec get_and_update(t, Statement.coercible_subject(), get_and_update_description_fun) ::
{Description.t(), input}
def get_and_update(%__MODULE__{} = graph, subject, fun) do
subject = coerce_subject(subject)
case fun.(get(graph, subject)) do
{old_description, new_description} ->
{old_description, put(graph, {subject, new_description})}
:pop ->
pop(graph, subject)
other ->
raise "the given function must return a two-element tuple or :pop, got: #{inspect(other)}"
end
end
@doc """
Pops an arbitrary triple from a `RDF.Graph`.
"""
@spec pop(t) :: {Statement.t() | nil, t}
def pop(graph)
def pop(%__MODULE__{descriptions: descriptions} = graph)
when descriptions == %{},
do: {nil, graph}
def pop(%__MODULE__{descriptions: descriptions} = graph) do
# TODO: Find a faster way ...
[{subject, description}] = Enum.take(descriptions, 1)
{triple, popped_description} = Description.pop(description)
popped =
if Enum.empty?(popped_description),
do: descriptions |> Map.delete(subject),
else: descriptions |> Map.put(subject, popped_description)
{triple, %__MODULE__{graph | descriptions: popped}}
end
@doc """
Pops the description of the given subject.
When the subject can not be found the optionally given default value or `nil` is returned.
## Examples
iex> RDF.Graph.new([{EX.S1, EX.P1, EX.O1}, {EX.S2, EX.P2, EX.O2}])
...> |> RDF.Graph.pop(EX.S1)
{RDF.Description.new(EX.S1, init: {EX.P1, EX.O1}), RDF.Graph.new({EX.S2, EX.P2, EX.O2})}
iex> RDF.Graph.new({EX.S, EX.P, EX.O}) |> RDF.Graph.pop(EX.Missing)
{nil, RDF.Graph.new({EX.S, EX.P, EX.O})}
"""
@impl Access
@spec pop(t, Statement.coercible_subject()) :: {Description.t() | nil, t}
def pop(%__MODULE__{} = graph, subject) do
case Access.pop(graph.descriptions, coerce_subject(subject)) do
{nil, _} ->
{nil, graph}
{description, new_descriptions} ->
{description, %__MODULE__{graph | descriptions: new_descriptions}}
end
end
@doc """
The number of subjects within a `RDF.Graph`.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}])
...> |> RDF.Graph.subject_count()
2
"""
@spec subject_count(t) :: non_neg_integer
def subject_count(%__MODULE__{} = graph) do
Enum.count(graph.descriptions)
end
@doc """
The number of statements within a `RDF.Graph`.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}])
...> |> RDF.Graph.statement_count()
3
"""
@spec statement_count(t) :: non_neg_integer
def statement_count(%__MODULE__{} = graph) do
Enum.reduce(graph.descriptions, 0, fn {_subject, description}, count ->
count + Description.count(description)
end)
end
defdelegate triple_count(graph), to: __MODULE__, as: :statement_count
@doc """
The set of all subjects used in the statements within a `RDF.Graph`.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}])
...> |> RDF.Graph.subjects()
MapSet.new([RDF.iri(EX.S1), RDF.iri(EX.S2)])
"""
def subjects(%__MODULE__{} = graph) do
graph.descriptions |> Map.keys() |> MapSet.new()
end
@doc """
The set of all properties used in the predicates of the statements within a `RDF.Graph`.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}])
...> |> RDF.Graph.predicates()
MapSet.new([EX.p1, EX.p2])
"""
def predicates(%__MODULE__{} = graph) do
Enum.reduce(graph.descriptions, MapSet.new(), fn {_, description}, acc ->
description
|> Description.predicates()
|> MapSet.union(acc)
end)
end
@doc """
The set of all resources used in the objects within a `RDF.Graph`.
Note: This function does collect only IRIs and BlankNodes, not Literals.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S3, EX.p1, EX.O2},
...> {EX.S4, EX.p2, RDF.bnode(:bnode)},
...> {EX.S5, EX.p3, "foo"}])
...> |> RDF.Graph.objects()
MapSet.new([RDF.iri(EX.O1), RDF.iri(EX.O2), RDF.bnode(:bnode)])
"""
def objects(%__MODULE__{} = graph) do
Enum.reduce(graph.descriptions, MapSet.new(), fn {_, description}, acc ->
description
|> Description.objects()
|> MapSet.union(acc)
end)
end
@doc """
The set of all resources used within a `RDF.Graph`.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p1, EX.O2},
...> {EX.S2, EX.p2, RDF.bnode(:bnode)},
...> {EX.S3, EX.p1, "foo"}])
...> |> RDF.Graph.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(graph = %__MODULE__{} = graph) do
Enum.reduce(graph.descriptions, MapSet.new(), fn {_, description}, acc ->
description
|> Description.resources()
|> MapSet.union(acc)
end)
|> MapSet.union(subjects(graph))
end
@doc """
The list of all statements within a `RDF.Graph`.
## Examples
iex> RDF.Graph.new([
...> {EX.S1, EX.p1, EX.O1},
...> {EX.S2, EX.p2, EX.O2},
...> {EX.S1, EX.p2, EX.O3}])
...> |> RDF.Graph.triples()
[{RDF.iri(EX.S1), RDF.iri(EX.p1), RDF.iri(EX.O1)},
{RDF.iri(EX.S1), RDF.iri(EX.p2), RDF.iri(EX.O3)},
{RDF.iri(EX.S2), RDF.iri(EX.p2), RDF.iri(EX.O2)}]
"""
@spec triples(t) :: [Statement.t()]
def triples(%__MODULE__{} = graph) do
Enum.flat_map(graph.descriptions, fn {_, description} ->
Description.triples(description)
end)
end
defdelegate statements(graph), to: __MODULE__, as: :triples
@doc """
Checks if the given `input` statements exist within `graph`.
"""
@spec include?(t, input, keyword) :: boolean
def include?(graph, input, opts \\ [])
def include?(%__MODULE__{} = graph, {subject, _, _} = triple, opts),
do: do_include?(graph, coerce_subject(subject), triple, opts)
def include?(graph, {subject, predicate, object, _}, opts),
do: include?(graph, {subject, predicate, object}, opts)
def include?(%__MODULE__{} = graph, {subject, predications}, opts),
do: do_include?(graph, coerce_subject(subject), predications, opts)
def include?(%__MODULE__{} = graph, %Description{subject: subject} = description, opts),
do: do_include?(graph, subject, description, opts)
def include?(graph, %__MODULE__{} = other_graph, opts) do
other_graph
|> descriptions()
|> Enum.all?(&include?(graph, &1, opts))
end
if Version.match?(System.version(), "~> 1.10") do
def include?(graph, input, opts)
when is_list(input) or (is_map(input) and not is_struct(input)) do
Enum.all?(input, &include?(graph, &1, opts))
end
else
def include?(_, %_{}, _), do: raise(ArgumentError, "structs are not allowed as input")
def include?(graph, input, opts) when is_list(input) or is_map(input) do
Enum.all?(input, &include?(graph, &1, opts))
end
end
defp do_include?(%__MODULE__{descriptions: descriptions}, subject, input, opts) do
if description = descriptions[subject] do
Description.include?(description, input, opts)
else
false
end
end
@doc """
Checks if a `RDF.Graph` contains statements about the given resource.
## Examples
iex> RDF.Graph.new([{EX.S1, EX.p1, EX.O1}]) |> RDF.Graph.describes?(EX.S1)
true
iex> RDF.Graph.new([{EX.S1, EX.p1, EX.O1}]) |> RDF.Graph.describes?(EX.S2)
false
"""
@spec describes?(t, Statement.coercible_subject()) :: boolean
def describes?(%__MODULE__{} = graph, subject) do
Map.has_key?(graph.descriptions, coerce_subject(subject))
end
@doc """
Returns a nested map of the native Elixir values of a `RDF.Graph`.
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> RDF.Graph.new([
...> {~I<http://example.com/S1>, ~I<http://example.com/p>, ~L"Foo"},
...> {~I<http://example.com/S2>, ~I<http://example.com/p>, RDF.XSD.integer(42)}
...> ])
...> |> RDF.Graph.values()
%{
"http://example.com/S1" => %{"http://example.com/p" => ["Foo"]},
"http://example.com/S2" => %{"http://example.com/p" => [42]}
}
iex> RDF.Graph.new([
...> {~I<http://example.com/S1>, ~I<http://example.com/p>, ~L"Foo"},
...> {~I<http://example.com/S2>, ~I<http://example.com/p>, RDF.XSD.integer(42)}
...> ])
...> |> RDF.Graph.values(context: [p: ~I<http://example.com/p>])
%{
"http://example.com/S1" => %{p: ["Foo"]},
"http://example.com/S2" => %{p: [42]}
}
"""
@spec values(t, keyword) :: map
def values(%__MODULE__{} = graph, opts \\ []) do
if property_map = PropertyMap.from_opts(opts) do
map(graph, Statement.default_property_mapping(property_map))
else
map(graph, &Statement.default_term_mapping/1)
end
end
@doc """
Returns a nested map of a `RDF.Graph` where each element from its triples 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` or `:object`,
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> RDF.Graph.new([
...> {~I<http://example.com/S1>, ~I<http://example.com/p>, ~L"Foo"},
...> {~I<http://example.com/S2>, ~I<http://example.com/p>, RDF.XSD.integer(42)}
...> ])
...> |> RDF.Graph.map(fn
...> {:predicate, predicate} ->
...> predicate
...> |> to_string()
...> |> String.split("/")
...> |> List.last()
...> |> String.to_atom()
...> {_, term} ->
...> RDF.Term.value(term)
...> end)
%{
"http://example.com/S1" => %{p: ["Foo"]},
"http://example.com/S2" => %{p: [42]}
}
"""
@spec map(t, Statement.term_mapping()) :: map
def map(description, fun)
def map(%__MODULE__{} = graph, fun) do
Map.new(graph.descriptions, fn {subject, description} ->
{
fun.({:subject, subject}),
Description.map(description, fun)
}
end)
end
@doc """
Creates a graph from another one by limiting its statements to those using one of the given `subjects`.
If `subjects` contains IRIs that are not used in the `graph`, they're simply ignored.
The optional `properties` argument allows to limit also properties of the subject descriptions.
If `nil` is passed as the `subjects`, the subjects will not be limited.
"""
@spec take(
t,
[Statement.coercible_subject()] | Enum.t() | nil,
[Statement.coercible_predicate()] | Enum.t() | nil
) :: t
def take(graph, subjects, properties \\ nil)
def take(%__MODULE__{} = graph, nil, nil), do: graph
def take(%__MODULE__{descriptions: descriptions} = graph, subjects, nil) do
%__MODULE__{
graph
| descriptions: Map.take(descriptions, Enum.map(subjects, &coerce_subject/1))
}
end
def take(%__MODULE__{} = graph, subjects, properties) do
graph = take(graph, subjects, nil)
%__MODULE__{
graph
| descriptions:
Map.new(graph.descriptions, fn {subject, description} ->
{subject, Description.take(description, properties)}
end)
}
end
@doc """
Checks if two `RDF.Graph`s are equal.
Two `RDF.Graph`s are considered to be equal if they contain the same triples
and have the same name. The prefixes of the graph are irrelevant for equality.
"""
@spec equal?(t | any, t | any) :: boolean
def equal?(graph1, graph2)
def equal?(%__MODULE__{} = graph1, %__MODULE__{} = graph2) do
clear_metadata(graph1) == clear_metadata(graph2)
end
def equal?(_, _), do: false
@doc """
Returns the prefixes of the given `graph` as a `RDF.PrefixMap`.
"""
@spec prefixes(t) :: PrefixMap.t() | nil
def prefixes(%__MODULE__{} = graph), do: graph.prefixes
@doc """
Adds `prefixes` to the given `graph`.
The `prefixes` mappings can be given as any structure convertible to a
`RDF.PrefixMap`.
When a prefix with another mapping already exists it will be overwritten with
the new one. This behaviour can be customized by providing a `conflict_resolver`
function. See `RDF.PrefixMap.merge/3` for more on that.
"""
@spec add_prefixes(
t,
PrefixMap.t() | map | keyword | nil,
PrefixMap.conflict_resolver() | nil
) :: t
def add_prefixes(graph, prefixes, conflict_resolver \\ nil)
def add_prefixes(%__MODULE__{} = graph, nil, _), do: graph
def add_prefixes(%__MODULE__{prefixes: nil} = graph, prefixes, _) do
%__MODULE__{graph | prefixes: PrefixMap.new(prefixes)}
end
def add_prefixes(%__MODULE__{} = graph, additions, nil) do
add_prefixes(graph, additions, :overwrite)
end
def add_prefixes(%__MODULE__{prefixes: prefixes} = graph, additions, conflict_resolver) do
%__MODULE__{graph | prefixes: PrefixMap.merge!(prefixes, additions, conflict_resolver)}
end
@doc """
Deletes `prefixes` from the given `graph`.
The `prefixes` can be a single prefix or a list of prefixes.
Prefixes not in prefixes of the graph are simply ignored.
"""
@spec delete_prefixes(t, PrefixMap.t()) :: t
def delete_prefixes(graph, prefixes)
def delete_prefixes(%__MODULE__{prefixes: nil} = graph, _), do: graph
def delete_prefixes(%__MODULE__{} = graph, deletions) do
%__MODULE__{graph | prefixes: PrefixMap.drop(graph.prefixes, List.wrap(deletions))}
end
@doc """
Clears all prefixes of the given `graph`.
"""
@spec clear_prefixes(t) :: t
def clear_prefixes(%__MODULE__{} = graph) do
%__MODULE__{graph | prefixes: nil}
end
@doc """
Returns the base IRI of the given `graph`.
"""
@spec base_iri(t) :: IRI.t() | nil
def base_iri(%__MODULE__{} = graph), do: graph.base_iri
@doc """
Sets the base IRI of the given `graph`.
The `base_iri` can be given as anything accepted by `RDF.IRI.coerce_base/1`.
"""
@spec set_base_iri(t, IRI.t() | nil) :: t
def set_base_iri(graph, base_iri)
def set_base_iri(%__MODULE__{} = graph, nil) do
%__MODULE__{graph | base_iri: nil}
end
def set_base_iri(%__MODULE__{} = graph, base_iri) do
%__MODULE__{graph | base_iri: IRI.coerce_base(base_iri)}
end
@doc """
Clears the base IRI of the given `graph`.
"""
@spec clear_base_iri(t) :: t
def clear_base_iri(%__MODULE__{} = graph) do
%__MODULE__{graph | base_iri: nil}
end
@doc """
Clears the base IRI and all prefixes of the given `graph`.
"""
@spec clear_metadata(t) :: t
def clear_metadata(%__MODULE__{} = graph) do
graph
|> clear_base_iri()
|> clear_prefixes()
end
defimpl Enumerable do
alias RDF.Graph
def member?(graph, triple), do: {:ok, Graph.include?(graph, triple)}
def count(graph), do: {:ok, Graph.statement_count(graph)}
if Version.match?(System.version(), "~> 1.10") do
def slice(graph) do
size = Graph.statement_count(graph)
{:ok, size, &Enumerable.List.slice(Graph.triples(graph), &1, &2, size)}
end
else
def slice(_), do: {:error, __MODULE__}
end
def reduce(graph, acc, fun) do
graph
|> Graph.triples()
|> Enumerable.List.reduce(acc, fun)
end
end
defimpl Collectable do
alias RDF.Graph
def into(original) do
collector_fun = fn
graph, {:cont, list} when is_list(list) ->
Graph.add(graph, List.to_tuple(list))
graph, {:cont, elem} ->
Graph.add(graph, elem)
graph, :done ->
graph
_graph, :halt ->
:ok
end
{original, collector_fun}
end
end
end