5 files changed, 129 insertions, 0 deletions
diff --git a/activerecord/lib/arel/collectors/bind.rb b/activerecord/lib/arel/collectors/bind.rb
new file mode 100644
index 0000000000..6f8912575d
--- /dev/null
+++ b/activerecord/lib/arel/collectors/bind.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  module Collectors
+    class Bind
+      def initialize
+        @binds = []
+      end
+
+      def <<(str)
+        self
+      end
+
+      def add_bind(bind)
+        @binds << bind
+        self
+      end
+
+      def value
+        @binds
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/arel/collectors/composite.rb b/activerecord/lib/arel/collectors/composite.rb
new file mode 100644
index 0000000000..d040d8598d
--- /dev/null
+++ b/activerecord/lib/arel/collectors/composite.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  module Collectors
+    class Composite
+      def initialize(left, right)
+        @left = left
+        @right = right
+      end
+
+      def <<(str)
+        left << str
+        right << str
+        self
+      end
+
+      def add_bind(bind, &block)
+        left.add_bind bind, &block
+        right.add_bind bind, &block
+        self
+      end
+
+      def value
+        [left.value, right.value]
+      end
+
+      protected
+
+        attr_reader :left, :right
+    end
+  end
+end
diff --git a/activerecord/lib/arel/collectors/plain_string.rb b/activerecord/lib/arel/collectors/plain_string.rb
new file mode 100644
index 0000000000..687d7fbf2f
--- /dev/null
+++ b/activerecord/lib/arel/collectors/plain_string.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  module Collectors
+    class PlainString
+      def initialize
+        @str = "".dup
+      end
+
+      def value
+        @str
+      end
+
+      def <<(str)
+        @str << str
+        self
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/arel/collectors/sql_string.rb b/activerecord/lib/arel/collectors/sql_string.rb
new file mode 100644
index 0000000000..c293a89a74
--- /dev/null
+++ b/activerecord/lib/arel/collectors/sql_string.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require "arel/collectors/plain_string"
+
+module Arel # :nodoc: all
+  module Collectors
+    class SQLString < PlainString
+      def initialize(*)
+        super
+        @bind_index = 1
+      end
+
+      def add_bind(bind)
+        self << yield(@bind_index)
+        @bind_index += 1
+        self
+      end
+
+      def compile(bvs)
+        value
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/arel/collectors/substitute_binds.rb b/activerecord/lib/arel/collectors/substitute_binds.rb
new file mode 100644
index 0000000000..3f40eec8a8
--- /dev/null
+++ b/activerecord/lib/arel/collectors/substitute_binds.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  module Collectors
+    class SubstituteBinds
+      def initialize(quoter, delegate_collector)
+        @quoter = quoter
+        @delegate = delegate_collector
+      end
+
+      def <<(str)
+        delegate << str
+        self
+      end
+
+      def add_bind(bind)
+        self << quoter.quote(bind)
+      end
+
+      def value
+        delegate.value
+      end
+
+      protected
+
+        attr_reader :quoter, :delegate
+    end
+  end
+end