Add ~i, ~b and ~l sigils

CHANGELOG.md

@@ -10,6 +10,8 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
 ### Added
 
 - a `RDF.Graph` builder DSL available under the `RDF.Graph.build/2` function
+- new `RDF.Sigils` `~i`, `~b` and `~l` as variants of the `~I`, `~B` and `~L`
+  sigils, which support string interpolation   
 - `RDF.Graph.new/2` and `RDF.Graph.add/2` support the addition of `RDF.Dataset`s
 - `RDF.Description.empty?/1`, `RDF.Graph.empty?/1`, `RDF.Dataset.empty?/1` and
   `RDF.Data.empty?/1` which are significantly faster than `Enum.empty?/1`

lib/rdf/sigils.ex

@@ -6,7 +6,9 @@ defmodule RDF.Sigils do
   @doc ~S"""
   Handles the sigil `~I` for IRIs.
 
-  Note: The given IRI string is precompiled into an `RDF.IRI` struct.
+  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
 
@@ -19,9 +21,36 @@ defmodule RDF.Sigils 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
@@ -33,9 +62,34 @@ defmodule RDF.Sigils 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.
@@ -58,4 +112,49 @@ defmodule RDF.Sigils do
   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

test/unit/sigils_test.exs

@@ -5,25 +5,67 @@ defmodule RDF.SigilsTest do
 
   doctest RDF.Sigils
 
-  describe "IRI sigil without interpolation" do
-    test "creating an IRI" do
+  describe "~I sigil" do
+    test "creates an IRI" do
       assert ~I<http://example.com> == RDF.iri("http://example.com")
     end
+
+    test "escaping" do
+      assert ~I<http://example.com/f\no> == RDF.iri("http://example.com/f\\no")
+    end
   end
 
-  describe "Blank node sigil without interpolation" do
-    test "creating a blank node" do
+  describe "~i sigil" do
+    test "without interpolation" do
+      assert ~i<http://example.com> == RDF.iri("http://example.com")
+    end
+
+    test "with interpolation" do
+      assert ~i<http://example.com/#{1 + 2}> == RDF.iri("http://example.com/3")
+      assert ~i<http://example.com/#{:foo}> == RDF.iri("http://example.com/foo")
+      assert ~i<http://example.com/#{"foo"}> == RDF.iri("http://example.com/foo")
+    end
+
+    test "escaping" do
+      assert ~i<http://example.com/f\no> == RDF.iri("http://example.com/f\\no")
+    end
+  end
+
+  describe "~B sigil" do
+    test "creates a blank node" do
       assert ~B<foo> == RDF.bnode("foo")
     end
   end
 
-  describe "Literal sigil without interpolation" do
-    test "creating a plain Literal" do
+  describe "~b sigil" do
+    test "without interpolation" do
+      assert ~b<foo> == RDF.bnode("foo")
+    end
+
+    test "with interpolation" do
+      assert ~b<foo#{1 + 2}> == RDF.bnode("foo3")
+    end
+  end
+
+  describe "~L sigil" do
+    test "creates a plain Literal" do
       assert ~L"foo" == RDF.literal("foo")
     end
 
-    test "creating a language-tagged Literal" do
+    test "creates a language-tagged Literal" do
       assert ~L"foo"en == RDF.literal("foo", language: "en")
     end
   end
+
+  describe "~l sigil" do
+    test "without interpolation" do
+      assert ~l"foo" == RDF.literal("foo")
+      assert ~l"foo"en == RDF.literal("foo", language: "en")
+    end
+
+    test "with interpolation" do
+      assert ~l"foo#{1 + 2}" == RDF.literal("foo3")
+      assert ~l"foo#{1 + 2}"en == RDF.literal("foo3", language: "en")
+    end
+  end
 end