rdf-ex/lib/rdf/sigils.ex
2022-04-09 21:15:34 +02:00

160 lines
4.1 KiB
Elixir

defmodule RDF.Sigils do
@moduledoc """
Sigils for the most common types of RDF nodes.
"""
@doc ~S"""
Handles the sigil `~I` for IRIs.
It returns an `RDF.IRI` from the given string without interpolations and
without escape characters, except for the escaping of the closing sigil
character itself.
## Examples
iex> import RDF.Sigils
iex> ~I<http://example.com>
RDF.iri("http://example.com")
"""
defmacro sigil_I({:<<>>, _, [iri]}, []) when is_binary(iri) do
Macro.escape(RDF.iri!(iri))
end
@doc ~S"""
Handles the sigil `~i` for IRIs.
It returns an `RDF.IRI` from the given string as if it was a double quoted
string, unescaping characters and replacing interpolations.
## Examples
iex> import RDF.Sigils
iex> ~i<http://example.com/#{String.downcase("Foo")}>
RDF.iri("http://example.com/foo")
"""
defmacro sigil_i({:<<>>, _, [iri]}, []) when is_binary(iri) do
Macro.escape(RDF.iri!(iri))
end
defmacro sigil_i({:<<>>, line, pieces}, []) do
quote do
RDF.iri!(unquote({:<<>>, line, unescape_tokens(pieces)}))
end
end
@doc ~S"""
Handles the sigil `~B` for blank nodes.
It returns an `RDF.BlankNode` from the given string without interpolations
and without escape characters, except for the escaping of the closing sigil
character itself.
## Examples
iex> import RDF.Sigils
iex> ~B<foo>
RDF.bnode("foo")
"""
defmacro sigil_B({:<<>>, _, [bnode]}, []) when is_binary(bnode) do
Macro.escape(RDF.BlankNode.new(bnode))
end
@doc ~S"""
Handles the sigil `~b` for blank nodes.
It returns an `RDF.BlankNode` from the given string as if it was a double quoted
string, unescaping characters and replacing interpolations.
## Examples
iex> import RDF.Sigils
iex> ~b<foo#{String.downcase("Bar")}>
RDF.bnode("foobar")
"""
defmacro sigil_b({:<<>>, _, [bnode]}, []) when is_binary(bnode) do
Macro.escape(RDF.BlankNode.new(bnode))
end
defmacro sigil_b({:<<>>, line, pieces}, []) do
quote do
RDF.BlankNode.new(unquote({:<<>>, line, unescape_tokens(pieces)}))
end
end
@doc ~S"""
Handles the sigil `~L` for plain Literals.
It returns an `RDF.Literal` from the given string without interpolations and without escape characters, except for the escaping of the closing sigil character itself.
The sigil modifier can be used to specify a language tag.
Note: Languages with subtags are not supported.
## Examples
iex> import RDF.Sigils
iex> ~L"foo"
RDF.literal("foo")
iex> ~L"foo"en
RDF.literal("foo", language: "en")
"""
defmacro sigil_L(value, language)
defmacro sigil_L({:<<>>, _, [value]}, []) when is_binary(value) do
Macro.escape(RDF.XSD.String.new(value))
end
defmacro sigil_L({:<<>>, _, [value]}, language) when is_binary(value) do
Macro.escape(RDF.LangString.new(value, language: to_string(language)))
end
@doc ~S"""
Handles the sigil `~l` for blank nodes.
It returns an `RDF.Literal` from the given string as if it was a double quoted
string, unescaping characters and replacing interpolations.
## Examples
iex> import RDF.Sigils
iex> ~l"foo #{String.downcase("Bar")}"
RDF.literal("foo bar")
iex> ~l"foo #{String.downcase("Bar")}"en
RDF.literal("foo bar", language: "en")
"""
defmacro sigil_l(value, language)
defmacro sigil_l({:<<>>, _, [value]}, []) when is_binary(value) do
Macro.escape(RDF.XSD.String.new(value))
end
defmacro sigil_l({:<<>>, _, [value]}, language) when is_binary(value) do
Macro.escape(RDF.LangString.new(value, language: to_string(language)))
end
defmacro sigil_l({:<<>>, line, pieces}, []) do
quote do
RDF.XSD.String.new(unquote({:<<>>, line, unescape_tokens(pieces)}))
end
end
defmacro sigil_l({:<<>>, line, pieces}, language) do
quote do
RDF.LangString.new(unquote({:<<>>, line, unescape_tokens(pieces)}),
language: to_string(unquote(language))
)
end
end
defp unescape_tokens(tokens) do
for token <- tokens do
if is_binary(token), do: Macro.unescape_string(token), else: token
end
end
end