change concat (and friends) signature

In most use cases you only need an empty vega lite struct so the first
argument is removed. Instead an optional `opts` is added for setting the
parent plots settings if needed.

lib/tucan.ex

@@ -917,7 +917,7 @@ defmodule Tucan do
       |> Tucan.set_size(160, 160)
     end
 
-  Tucan.hconcat(Tucan.new(), plots)
+  Tucan.hconcat(plots)
   ```
 
   You can use `:line_color` and `:stroke_width` to modify the look of the error bars:
@@ -2165,8 +2165,7 @@ defmodule Tucan do
       |> Tucan.set_title(interpolation)
     end
 
-  VegaLite.new(columns: 2)
-  |> Tucan.concat(plots)
+  Tucan.concat(plots, columns: 2)
   ```
   """
   @doc section: :plots
@@ -3307,18 +3306,18 @@ defmodule Tucan do
   Concatenates horizontally the given plots.
   """
   @doc section: :layout
-  @spec hconcat(vl :: VegaLite.t(), plots :: [VegaLite.t()]) :: VegaLite.t()
-  def hconcat(vl \\ Vl.new(), plots) when is_list(plots) do
-    VegaLite.concat(vl, plots, :horizontal)
+  @spec hconcat(plots :: [VegaLite.t()], opts :: keyword()) :: VegaLite.t()
+  def hconcat(plots, opts \\ []) when is_list(plots) do
+    VegaLite.concat(Vl.new(opts), plots, :horizontal)
   end
 
   @doc """
   Concatenates vertically the given plots.
   """
   @doc section: :layout
-  @spec vconcat(vl :: VegaLite.t(), plots :: [VegaLite.t()]) :: VegaLite.t()
-  def vconcat(vl \\ Vl.new(), plots) when is_list(plots) do
-    VegaLite.concat(vl, plots, :vertical)
+  @spec vconcat(plots :: [VegaLite.t()], opts :: keyword()) :: VegaLite.t()
+  def vconcat(plots, opts \\ []) when is_list(plots) do
+    VegaLite.concat(Vl.new(opts), plots, :vertical)
   end
 
   @doc """
@@ -3327,9 +3326,9 @@ defmodule Tucan do
   This corresponds to the general concatenation of vega-lite (wrappable).
   """
   @doc section: :layout
-  @spec concat(vl :: VegaLite.t(), plots :: [VegaLite.t()]) :: VegaLite.t()
-  def concat(vl \\ Vl.new(), plots) when is_list(plots) do
-    VegaLite.concat(vl, plots, :wrappable)
+  @spec concat(plots :: [VegaLite.t()], opts :: keyword()) :: VegaLite.t()
+  def concat(plots, opts \\ []) when is_list(plots) do
+    VegaLite.concat(Vl.new(opts), plots, :wrappable)
   end
 
   @doc """

lib/tucan/scale.ex

@@ -39,8 +39,7 @@ defmodule Tucan.Scale.Utils do
         )
       end
 
-    Vl.new(columns: 2)
-    |> Tucan.concat(plots)
+    Tucan.concat(plots, columns: 2)
     |> Vl.resolve(:scale, color: :independent)
     |> Vl.to_spec()
     |> Jason.encode!()
@@ -405,7 +404,7 @@ defmodule Tucan.Scale do
   defp validate_scale_options!(_type, opts), do: Keyword.validate!(opts, [])
 
   @doc """
-  Sets the same `[x, y]` domain for _x-axis_ and _y-axis_ at once. 
+  Sets the same `[x, y]` domain for _x-axis_ and _y-axis_ at once.
   """
   @spec set_xy_domain(vl :: VegaLite.t(), min :: number(), max :: number()) :: VegaLite.t()
   def set_xy_domain(vl, min, max) do

lib/tucan/view.ex

@@ -32,7 +32,6 @@ defmodule Tucan.View do
 
   ```tucan
   Tucan.hconcat(
-    Tucan.new(),
     [
       Tucan.scatter(:iris, "sepal_width", "sepal_length")
       |> Tucan.View.set_view_background("#e6fae1"),

test/tucan_test.exs

@@ -1532,10 +1532,13 @@ defmodule TucanTest do
       expected =
         Vl.new(bounds: :flush, spacing: 15)
         |> Vl.data_from_url(@iris_dataset)
-        |> Tucan.vconcat([
-          marginal_x,
-          Tucan.hconcat(Vl.new(bounds: :flush, spacing: 15), [joint, marginal_y])
-        ])
+        |> Vl.concat(
+          [
+            marginal_x,
+            Vl.concat(Vl.new(bounds: :flush, spacing: 15), [joint, marginal_y], :horizontal)
+          ],
+          :vertical
+        )
 
       assert(Tucan.jointplot(:iris, "petal_width", "petal_length") == expected)
     end
@@ -1559,10 +1562,13 @@ defmodule TucanTest do
       expected =
         Vl.new(bounds: :flush, spacing: 10)
         |> Vl.data_from_url(@iris_dataset)
-        |> Tucan.vconcat([
-          marginal_x,
-          Tucan.hconcat(Vl.new(bounds: :flush, spacing: 10), [joint, marginal_y])
-        ])
+        |> Vl.concat(
+          [
+            marginal_x,
+            Vl.concat(Vl.new(bounds: :flush, spacing: 10), [joint, marginal_y], :horizontal)
+          ],
+          :vertical
+        )
 
       assert(
         Tucan.jointplot(:iris, "petal_width", "petal_length",
@@ -1594,10 +1600,13 @@ defmodule TucanTest do
       expected =
         Vl.new(bounds: :flush, spacing: 15)
         |> Vl.data_from_url(@iris_dataset)
-        |> Tucan.vconcat([
-          marginal_x,
-          Tucan.hconcat(Vl.new(bounds: :flush, spacing: 15), [joint, marginal_y])
-        ])
+        |> Vl.concat(
+          [
+            marginal_x,
+            Vl.concat(Vl.new(bounds: :flush, spacing: 15), [joint, marginal_y], :horizontal)
+          ],
+          :vertical
+        )
 
       assert(
         Tucan.jointplot(:iris, "petal_width", "petal_length",
@@ -1627,10 +1636,13 @@ defmodule TucanTest do
       expected =
         Vl.new(bounds: :flush, spacing: 15)
         |> Vl.data_from_url(@iris_dataset)
-        |> Tucan.vconcat([
-          marginal_x,
-          Tucan.hconcat(Vl.new(bounds: :flush, spacing: 15), [joint, marginal_y])
-        ])
+        |> Vl.concat(
+          [
+            marginal_x,
+            Vl.concat(Vl.new(bounds: :flush, spacing: 15), [joint, marginal_y], :horizontal)
+          ],
+          :vertical
+        )
 
       assert(
         Tucan.jointplot(:iris, "petal_width", "petal_length",
@@ -1935,25 +1947,14 @@ defmodule TucanTest do
   end
 
   describe "concat and friends" do
-    test "with no input plot" do
+    test "with default options" do
       plot1 = Tucan.scatter(@dataset, "x", "y")
       plot2 = Tucan.scatter(@dataset, "x", "y")
 
       assert Tucan.concat([plot1, plot2]) == Vl.concat(Vl.new(), [plot1, plot2], :wrappable)
       assert Tucan.hconcat([plot1, plot2]) == Vl.concat(Vl.new(), [plot1, plot2], :horizontal)
       assert Tucan.vconcat([plot1, plot2]) == Vl.concat(Vl.new(), [plot1, plot2], :vertical)
     end
-
-    test "with input plot" do
-      vl = VegaLite.new(width: 400, height: 300)
-
-      plot1 = Tucan.scatter(@dataset, "x", "y")
-      plot2 = Tucan.scatter(@dataset, "x", "y")
-
-      assert Tucan.concat(vl, [plot1, plot2]) == Vl.concat(vl, [plot1, plot2], :wrappable)
-      assert Tucan.hconcat(vl, [plot1, plot2]) == Vl.concat(vl, [plot1, plot2], :horizontal)
-      assert Tucan.vconcat(vl, [plot1, plot2]) == Vl.concat(vl, [plot1, plot2], :vertical)
-    end
   end
 
   describe "layers" do