add n_ary operators

app/models/logic/n_ary_operator.rb

@@ -0,0 +1,43 @@
+class Logic::NAryOperator < Logic::Term
+  attr_reader :operands
+
+  def initialize(operands)
+    @operands = operands
+  end
+
+  def to_h
+    {
+      "op" => self.class.name,
+      "operands" => @operands.map(&:to_h)
+    }
+  end
+
+  def self.from_h(h)
+    self.new(h['operands'].map { |operand_h| Logic.from_h(operand_h) })
+  end
+
+  def errors(stable_ids = [])
+    errors = []
+
+    if @operands.empty?
+      errors += ["opérateur '#{operator_name}' vide"]
+    end
+
+    not_booleans = @operands.filter { |operand| operand.type != :boolean }
+    if not_booleans.present?
+      errors += ["'#{operator_name}' ne contient pas que des booléens : #{not_booleans.map(&:to_s).join(', ')}"]
+    end
+
+    errors + @operands.flat_map { |operand| operand.errors(stable_ids) }
+  end
+
+  def type = :boolean
+
+  def ==(other)
+    self.class == other.class &&
+      @operands.count == other.operands.count &&
+      @operands.all? do |operand|
+        @operands.count { |o| o == operand } == other.operands.count { |o| o == operand }
+      end
+  end
+end