291 lines
8.7 KiB
Elixir
291 lines
8.7 KiB
Elixir
defmodule RDF.Serialization do
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@moduledoc """
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General functions for working with RDF serializations.
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"""
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alias RDF.{Dataset, Graph}
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@type format :: module
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@formats [
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RDF.Turtle,
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JSON.LD,
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RDF.NTriples,
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RDF.NQuads,
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]
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@doc """
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The list of all known `RDF.Serialization.Format`s in the RDF.ex eco-system.
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Note: Not all known formats might be available to an application, see `available_formats/0`.
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## Examples
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iex> RDF.Serialization.formats
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[RDF.Turtle, JSON.LD, RDF.NTriples, RDF.NQuads]
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"""
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@spec formats :: [format]
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def formats, do: @formats
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@doc """
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The list of all available `RDF.Serialization.Format`s in an application.
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A known format might not be available in an application, when the format is
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implemented in an external library and this not specified as a Mix dependency
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of this application.
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## Examples
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iex> RDF.Serialization.available_formats
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[RDF.Turtle, RDF.NTriples, RDF.NQuads]
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"""
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@spec available_formats :: [format]
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def available_formats do
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Enum.filter @formats, &Code.ensure_loaded?/1
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end
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@doc """
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Returns the `RDF.Serialization.Format` with the given name, if available.
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## Examples
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iex> RDF.Serialization.format(:turtle)
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RDF.Turtle
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iex> RDF.Serialization.format("turtle")
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RDF.Turtle
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iex> RDF.Serialization.format(:jsonld)
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nil # unless json_ld is defined as a dependency of the application
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"""
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@spec format(String.t | atom) :: format | nil
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def format(name)
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def format(name) when is_binary(name) do
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name
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|> String.to_existing_atom
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|> format()
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rescue
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ArgumentError -> nil
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end
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def format(name) do
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format_where(fn format -> format.name == name end)
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end
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@doc """
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Returns the `RDF.Serialization.Format` with the given media type, if available.
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## Examples
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iex> RDF.Serialization.format_by_media_type("text/turtle")
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RDF.Turtle
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iex> RDF.Serialization.format_by_media_type("application/ld+json")
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nil # unless json_ld is defined as a dependency of the application
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"""
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@spec format_by_media_type(String.t) :: format | nil
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def format_by_media_type(media_type) do
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format_where(fn format -> format.media_type == media_type end)
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end
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@doc """
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Returns the proper `RDF.Serialization.Format` for the given file extension, if available.
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## Examples
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iex> RDF.Serialization.format_by_extension("ttl")
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RDF.Turtle
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iex> RDF.Serialization.format_by_extension(".ttl")
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RDF.Turtle
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iex> RDF.Serialization.format_by_extension("jsonld")
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nil # unless json_ld is defined as a dependency of the application
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"""
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@spec format_by_extension(String.t) :: format | nil
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def format_by_extension(extension)
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def format_by_extension("." <> extension), do: format_by_extension(extension)
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def format_by_extension(extension) do
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format_where(fn format -> format.extension == extension end)
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end
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defp format_where(fun) do
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@formats
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|> Stream.filter(&Code.ensure_loaded?/1)
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|> Enum.find(fun)
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end
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@doc """
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Reads and decodes a serialized graph or dataset from a string.
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The format must be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format.
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It returns an `{:ok, data}` tuple, with `data` being the deserialized graph or
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dataset, or `{:error, reason}` if an error occurs.
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"""
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@spec read_string(String.t, keyword) :: {:ok, Graph.t | Dataset.t} | {:error, any}
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def read_string(content, opts) do
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with {:ok, format} <- string_format(opts) do
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format.read_string(content, opts)
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end
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end
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@doc """
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Reads and decodes a serialized graph or dataset from a string.
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The format must be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format.
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As opposed to `read_string`, it raises an exception if an error occurs.
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"""
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@spec read_string!(String.t, keyword) :: Graph.t | Dataset.t
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def read_string!(content, opts) do
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with {:ok, format} <- string_format(opts) do
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format.read_string!(content, opts)
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else
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{:error, error} -> raise error
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end
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end
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@doc """
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Reads and decodes a serialized graph or dataset from a file.
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The format can be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format. If none of these are
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given, the format gets inferred from the extension of the given file name.
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It returns an `{:ok, data}` tuple, with `data` being the deserialized graph or
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dataset, or `{:error, reason}` if an error occurs.
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"""
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@spec read_file(Path.t, keyword) :: {:ok, Graph.t | Dataset.t} | {:error, any}
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def read_file(file, opts \\ []) do
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with {:ok, format} <- file_format(file, opts) do
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format.read_file(file, opts)
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end
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end
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@doc """
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Reads and decodes a serialized graph or dataset from a file.
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The format can be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format. If none of these are
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given, the format gets inferred from the extension of the given file name.
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As opposed to `read_file`, it raises an exception if an error occurs.
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"""
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@spec read_file!(Path.t, keyword) :: Graph.t | Dataset.t
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def read_file!(file, opts \\ []) do
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with {:ok, format} <- file_format(file, opts) do
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format.read_file!(file, opts)
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else
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{:error, error} -> raise error
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end
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end
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@doc """
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Encodes and writes a graph or dataset to a string.
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The format must be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format.
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It returns an `{:ok, string}` tuple, with `string` being the serialized graph or
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dataset, or `{:error, reason}` if an error occurs.
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"""
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@spec write_string(Graph.t | Dataset.t, keyword) :: {:ok, String.t} | {:error, any}
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def write_string(data, opts) do
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with {:ok, format} <- string_format(opts) do
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format.write_string(data, opts)
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end
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end
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@doc """
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Encodes and writes a graph or dataset to a string.
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The format must be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format.
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As opposed to `write_string`, it raises an exception if an error occurs.
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"""
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@spec write_string!(Graph.t | Dataset.t, keyword) :: String.t
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def write_string!(data, opts) do
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with {:ok, format} <- string_format(opts) do
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format.write_string!(data, opts)
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else
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{:error, error} -> raise error
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end
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end
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@doc """
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Encodes and writes a graph or dataset to a file.
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The format can be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format. If none of these are
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given, the format gets inferred from the extension of the given file name.
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Other available serialization-independent options:
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- `:force` - If not set to `true`, an error is raised when the given file
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already exists (default: `false`)
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- `:file_mode` - A list with the Elixir `File.open` modes to be used for writing
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(default: `[:utf8, :write]`)
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It returns `:ok` if successful or `{:error, reason}` if an error occurs.
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"""
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@spec write_file(Graph.t | Dataset.t, Path.t, keyword) :: :ok | {:error, any}
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def write_file(data, path, opts \\ []) do
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with {:ok, format} <- file_format(path, opts) do
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format.write_file(data, path, opts)
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end
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end
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@doc """
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Encodes and writes a graph or dataset to a file.
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The format can be specified with the `format` option and a format name or the
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`media_type` option and the media type of the format. If none of these are
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given, the format gets inferred from the extension of the given file name.
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See `write_file` for a list of other available options.
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As opposed to `write_file`, it raises an exception if an error occurs.
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"""
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@spec write_file!(Graph.t | Dataset.t, Path.t, keyword) :: :ok
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def write_file!(data, path, opts \\ []) do
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with {:ok, format} <- file_format(path, opts) do
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format.write_file!(data, path, opts)
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else
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{:error, error} -> raise error
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end
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end
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defp string_format(opts) do
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if format =
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(opts |> Keyword.get(:format) |> format()) ||
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(opts |> Keyword.get(:media_type) |> format_by_media_type())
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do
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{:ok, format}
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else
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{:error, "unable to detect serialization format"}
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end
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end
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defp file_format(filename, opts) do
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case string_format(opts) do
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{:ok, format} -> {:ok, format}
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_ -> format_by_file_name(filename)
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end
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end
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defp format_by_file_name(filename) do
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if format = filename |> Path.extname() |> format_by_extension() do
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{:ok, format}
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else
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{:error, "unable to detect serialization format"}
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end
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end
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end
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