improvement: support do/else blocks in if

improvement: support `cond`

lib/ash/filter/filter.ex

@@ -793,7 +793,17 @@ defmodule Ash.Filter do
         %{op | left: do_map(left, func), right: do_map(right, func)}
 
       %{__function__?: true, arguments: arguments} = func ->
-        %{func | arguments: Enum.map(arguments, &do_map(&1, func))}
+        %{
+          func
+          | arguments:
+              Enum.map(arguments, fn
+                {key, arg} when is_atom(key) ->
+                  {key, do_map(arg, func)}
+
+                arg ->
+                  do_map(arg, func)
+              end)
+        }
 
       other ->
         func.(other)
@@ -806,6 +816,9 @@ defmodule Ash.Filter do
 
   def update_aggregates(expression, mapper) do
     case expression do
+      {key, value} when is_atom(key) ->
+        {key, update_aggregates(value, mapper)}
+
       %Not{expression: expression} = not_expr ->
         %{not_expr | expression: update_aggregates(expression, mapper)}
 
@@ -1234,6 +1247,10 @@ defmodule Ash.Filter do
     [do_relationship_paths(left, kind), do_relationship_paths(right, kind)]
   end
 
+  defp do_relationship_paths({key, value}, kind) when is_atom(key) do
+    do_relationship_paths(value, kind)
+  end
+
   defp do_relationship_paths(%{__function__?: true, arguments: arguments}, kind) do
     Enum.map(arguments, &do_relationship_paths(&1, kind))
   end
@@ -1327,6 +1344,8 @@ defmodule Ash.Filter do
     Enum.flat_map(list, &list_refs/1)
   end
 
+  def list_refs({key, value}) when is_atom(key), do: list_refs(value)
+
   def list_refs(%__MODULE__{expression: expression}) do
     list_refs(expression)
   end
@@ -1419,7 +1438,7 @@ defmodule Ash.Filter do
          path
        ) do
     arguments
-    |> Enum.filter(&match?(%Ref{}, &1))
+    |> Enum.filter(fn arg -> match?(%Ref{}, arg) || match?({_, %Ref{}}, arg) end)
     |> Enum.any?(&List.starts_with?(&1.relationship_path, path))
     |> case do
       true ->
@@ -1434,6 +1453,8 @@ defmodule Ash.Filter do
     other
   end
 
+  defp scope_ref({key, %Ref{} = ref}, path), do: {key, scope_ref(ref, path)}
+
   defp scope_ref(%Ref{} = ref, path) do
     if List.starts_with?(ref.relationship_path, path) do
       %{ref | relationship_path: Enum.drop(ref.relationship_path, Enum.count(path))}
@@ -2006,6 +2027,16 @@ defmodule Ash.Filter do
   defp module_and_opts({module, opts}), do: {module, opts}
   defp module_and_opts(module), do: {module, []}
 
+  def hydrate_refs({key, value}, context) when is_atom(key) do
+    case hydrate_refs(value, context) do
+      {:ok, hydrated} ->
+        {:ok, {key, hydrated}}
+
+      other ->
+        other
+    end
+  end
+
   def hydrate_refs(
         %Ref{attribute: attribute} = ref,
         %{aggregates: aggregates, calculations: calculations} = context
@@ -2234,6 +2265,9 @@ defmodule Ash.Filter do
 
   defp add_to_predicate_path(expression, context) do
     case expression do
+      {key, value} when is_atom(key) ->
+        {key, add_to_predicate_path(value, context)}
+
       %Not{expression: expression} = not_expr ->
         %{not_expr | expression: add_to_predicate_path(expression, context)}
 

lib/ash/filter/runtime.ex

@@ -214,6 +214,16 @@ defmodule Ash.Filter.Runtime do
     end
   end
 
+  defp resolve_expr({key, value}, record) when is_atom(key) do
+    case resolve_expr(value, record) do
+      {:ok, resolved} ->
+        {:ok, {key, resolved}}
+
+      other ->
+        other
+    end
+  end
+
   defp resolve_expr(%Ref{} = ref, record) do
     {:ok, resolve_ref(ref, record)}
   end

lib/ash/query/call.ex

@@ -6,7 +6,54 @@ defmodule Ash.Query.Call do
   defimpl Inspect do
     import Inspect.Algebra
 
+    def inspect(%{name: :if, operator?: false, args: [condition, blocks]} = call, opts) do
+      if Keyword.keyword?(blocks) do
+        if Keyword.has_key?(blocks, :else) do
+          concat([
+            nest(
+              concat([
+                group(concat(["if ", to_doc(condition, opts), " do"])),
+                line(),
+                to_doc(blocks[:do], opts)
+              ]),
+              2
+            ),
+            line(),
+            "else",
+            nest(
+              concat([
+                line(),
+                to_doc(blocks[:else], opts)
+              ]),
+              2
+            ),
+            line(),
+            "end"
+          ])
+        else
+          concat([
+            nest(
+              concat([
+                group(concat(["if ", to_doc(condition, opts), " do"])),
+                line(),
+                to_doc(blocks[:do], opts)
+              ]),
+              2
+            ),
+            line(),
+            "end"
+          ])
+        end
+      else
+        do_inspect(call, opts)
+      end
+    end
+
     def inspect(call, inspect_opts) do
+      do_inspect(call, inspect_opts)
+    end
+
+    defp do_inspect(call, inspect_opts) do
       if call.operator? do
         concat([
           to_doc(Enum.at(call.args, 0), inspect_opts),

lib/ash/query/function/function.ex

@@ -27,23 +27,34 @@ defmodule Ash.Query.Function do
 
       mod_args ->
         configured_args = List.wrap(mod_args)
-        configured_arg_count = Enum.count(Enum.at(configured_args, 0))
+        allowed_arg_counts = Enum.map(configured_args, &Enum.count/1)
         given_arg_count = Enum.count(args)
 
-        if configured_arg_count == given_arg_count do
+        if given_arg_count in allowed_arg_counts do
           mod_args
+          |> Enum.filter(fn args ->
+            Enum.count(args) == given_arg_count
+          end)
           |> Enum.find_value(&try_cast_arguments(&1, args))
           |> case do
             nil ->
-              {:error,
+              {:error, "Could not cast function arguments for #{mod.name()}/#{given_arg_count}"}
-               "Could not cast function arguments for #{mod.name()}/#{configured_arg_count}"}
 
             casted ->
               mod.new(casted)
           end
         else
+          did_you_mean =
+            Enum.map_join(allowed_arg_counts, "\n", fn arg_count ->
+              " . * #{mod.name()}/#{arg_count}"
+            end)
+
           {:error,
-           "function #{mod.name()}/#{configured_arg_count} takes #{configured_arg_count} arguments, provided #{given_arg_count}"}
+           """
+             No such function #{mod.name()}/#{given_arg_count}. Did you mean one of:
+
+             #{did_you_mean}
+           """}
         end
     end
   end

lib/ash/query/function/if.ex

@@ -4,7 +4,23 @@ defmodule Ash.Query.Function.If do
   """
   use Ash.Query.Function, name: :if
 
-  def args, do: [[:boolean, :any, :any]]
+  def args, do: [[:boolean, :any], [:boolean, :any, :any]]
+
+  def new([condition, block]) do
+    if Keyword.keyword?(block) && Keyword.has_key?(block, :do) do
+      if Keyword.has_key?(block, :else) do
+        super([condition, block[:do], block[:else]])
+      else
+        super([condition, block[:do], nil])
+      end
+    else
+      super([condition, block, nil])
+    end
+  end
+
+  def new(other) do
+    super(other)
+  end
 
   def evaluate(%{arguments: [condition, when_true, when_false]}) do
     if condition do

lib/ash/query/query.ex

@@ -548,8 +548,29 @@ defmodule Ash.Query do
     soft_escape(Not.new(expression), escape?)
   end
 
+  defp do_expr({:cond, _, [[do: options]]}, escape?) do
+    options
+    |> Enum.map(fn {:->, _, [condition, result]} ->
+      {condition, result}
+    end)
+    |> cond_to_if_tree()
+    |> do_expr(escape?)
+  end
+
   defp do_expr({op, _, args}, escape?) when is_atom(op) and is_list(args) do
-    args = Enum.map(args, &do_expr(&1, false))
+    last_arg = List.last(args)
+
+    args =
+      if Keyword.keyword?(last_arg) && Keyword.has_key?(last_arg, :do) do
+        Enum.map(:lists.droplast(args), &do_expr(&1, false)) ++
+          [
+            Enum.map(last_arg, fn {key, arg_value} ->
+              {key, do_expr(arg_value, false)}
+            end)
+          ]
+      else
+        Enum.map(args, &do_expr(&1, false))
+      end
 
     soft_escape(%Ash.Query.Call{name: op, args: args, operator?: false}, escape?)
   end
@@ -558,6 +579,22 @@ defmodule Ash.Query do
 
   defp do_expr(other, _), do: other
 
+  defp cond_to_if_tree([{condition, result}]) do
+    {:if, [], [cond_condition(condition), [do: result]]}
+  end
+
+  defp cond_to_if_tree([{condition, result} | rest]) do
+    {:if, [], [cond_condition(condition), [do: result, else: cond_to_if_tree(rest)]]}
+  end
+
+  defp cond_condition([condition]) do
+    condition
+  end
+
+  defp cond_condition([condition | rest]) do
+    {:and, [], [condition, cond_condition(rest)]}
+  end
+
   defp soft_escape(%_{} = val, _) do
     {:%{}, [], Map.to_list(val)}
   end

lib/sat_solver.ex

@@ -149,6 +149,10 @@ defmodule Ash.SatSolver do
 
   defp upgrade_related_filters_to_join_keys(expr, _), do: expr
 
+  defp upgrade_ref({key, ref}, resource) when is_atom(key) do
+    {key, upgrade_ref(ref, resource)}
+  end
+
   defp upgrade_ref(
          %Ash.Query.Ref{attribute: attribute, relationship_path: path} = ref,
          resource

test/calculation_test.exs

@@ -60,6 +60,28 @@ defmodule Ash.Test.CalculationTest do
       calculate :conditional_full_name,
                 :string,
                 expr(if(first_name and last_name, first_name <> " " <> last_name, "(none)"))
+
+      calculate :conditional_full_name_block,
+                :string,
+                expr(
+                  if first_name and last_name do
+                    first_name <> " " <> last_name
+                  else
+                    "(none)"
+                  end
+                )
+
+      calculate :conditional_full_name_cond,
+                :string,
+                expr(
+                  cond do
+                    first_name and last_name ->
+                      first_name <> " " <> last_name
+
+                    true ->
+                      "(none)"
+                  end
+                )
     end
   end
 
@@ -185,4 +207,34 @@ defmodule Ash.Test.CalculationTest do
 
     assert full_names == ["(none)", "brian cranston", "zach daniel"]
   end
+
+  test "the `if` calculation can use the `do` style syntax" do
+    User
+    |> Ash.Changeset.new(%{first_name: "bob"})
+    |> Api.create!()
+
+    full_names =
+      User
+      |> Ash.Query.load(:conditional_full_name_block)
+      |> Api.read!()
+      |> Enum.map(& &1.conditional_full_name_block)
+      |> Enum.sort()
+
+    assert full_names == ["(none)", "brian cranston", "zach daniel"]
+  end
+
+  test "the `if` calculation can use the `cond` style syntax" do
+    User
+    |> Ash.Changeset.new(%{first_name: "bob"})
+    |> Api.create!()
+
+    full_names =
+      User
+      |> Ash.Query.load(:conditional_full_name_cond)
+      |> Api.read!()
+      |> Enum.map(& &1.conditional_full_name_cond)
+      |> Enum.sort()
+
+    assert full_names == ["(none)", "brian cranston", "zach daniel"]
+  end
 end