Move PG OID types to their own files

As we promote these classes to first class concepts, these classes are
starting to gain enough behavior to warrant being moved into their own
files. Many of them will become quite large as we move additional
behavior to the type objects.

23 files changed, 532 insertions, 353 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
index 1d0384c3df..e54c092bf6 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
@@ -1,360 +1,32 @@
+require 'active_record/connection_adapters/postgresql/oid/infinity'
+
+require 'active_record/connection_adapters/postgresql/oid/array'
+require 'active_record/connection_adapters/postgresql/oid/bit'
+require 'active_record/connection_adapters/postgresql/oid/bytea'
+require 'active_record/connection_adapters/postgresql/oid/cidr'
+require 'active_record/connection_adapters/postgresql/oid/date'
+require 'active_record/connection_adapters/postgresql/oid/date_time'
+require 'active_record/connection_adapters/postgresql/oid/decimal'
+require 'active_record/connection_adapters/postgresql/oid/enum'
+require 'active_record/connection_adapters/postgresql/oid/float'
+require 'active_record/connection_adapters/postgresql/oid/hstore'
+require 'active_record/connection_adapters/postgresql/oid/inet'
+require 'active_record/connection_adapters/postgresql/oid/integer'
+require 'active_record/connection_adapters/postgresql/oid/json'
+require 'active_record/connection_adapters/postgresql/oid/money'
+require 'active_record/connection_adapters/postgresql/oid/point'
+require 'active_record/connection_adapters/postgresql/oid/range'
+require 'active_record/connection_adapters/postgresql/oid/specialized_string'
+require 'active_record/connection_adapters/postgresql/oid/time'
+require 'active_record/connection_adapters/postgresql/oid/uuid'
+require 'active_record/connection_adapters/postgresql/oid/vector'
+
+require 'active_record/connection_adapters/postgresql/oid/type_map_initializer'
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
       module OID # :nodoc:
-        module Infinity
-          def infinity(options = {})
-            options[:negative] ? -::Float::INFINITY : ::Float::INFINITY
-          end
-        end
-
-        class SpecializedString < Type::String
-          attr_reader :type
-
-          def initialize(type)
-            @type = type
-          end
-
-          def text?
-            false
-          end
-        end
-
-        class Bit < Type::String
-          def type_cast(value)
-            if ::String === value
-              ConnectionAdapters::PostgreSQLColumn.string_to_bit value
-            else
-              value
-            end
-          end
-        end
-
-        class Bytea < Type::Binary
-          def cast_value(value)
-            PGconn.unescape_bytea value
-          end
-        end
-
-        class Money < Type::Decimal
-          include Infinity
-
-          def extract_scale(sql_type)
-            2
-          end
-
-          def cast_value(value)
-            return value unless ::String === value
-
-            # Because money output is formatted according to the locale, there are two
-            # cases to consider (note the decimal separators):
-            #  (1) $12,345,678.12
-            #  (2) $12.345.678,12
-            # Negative values are represented as follows:
-            #  (3) -$2.55
-            #  (4) ($2.55)
-
-            value.sub!(/^\((.+)\)$/, '-\1') # (4)
-            case value
-            when /^-?\D+[\d,]+\.\d{2}$/  # (1)
-              value.gsub!(/[^-\d.]/, '')
-            when /^-?\D+[\d.]+,\d{2}$/  # (2)
-              value.gsub!(/[^-\d,]/, '').sub!(/,/, '.')
-            end
-
-            super(value)
-          end
-        end
-
-        class Vector < Type::Value
-          attr_reader :delim, :subtype
-
-          # +delim+ corresponds to the `typdelim` column in the pg_types
-          # table.  +subtype+ is derived from the `typelem` column in the
-          # pg_types table.
-          def initialize(delim, subtype)
-            @delim   = delim
-            @subtype = subtype
-          end
-
-          # FIXME: this should probably split on +delim+ and use +subtype+
-          # to cast the values.  Unfortunately, the current Rails behavior
-          # is to just return the string.
-          def type_cast(value)
-            value
-          end
-        end
-
-        class Point < Type::String
-          def type_cast(value)
-            if ::String === value
-              ConnectionAdapters::PostgreSQLColumn.string_to_point value
-            else
-              value
-            end
-          end
-        end
-
-        class Array < Type::Value
-          attr_reader :subtype
-          delegate :type, to: :subtype
-
-          def initialize(subtype)
-            @subtype = subtype
-          end
-
-          def type_cast(value)
-            if ::String === value
-              ConnectionAdapters::PostgreSQLColumn.string_to_array value, @subtype
-            else
-              value
-            end
-          end
-        end
-
-        class Range < Type::Value
-          attr_reader :subtype, :type
-
-          def initialize(subtype, type)
-            @subtype = subtype
-            @type = type
-          end
-
-          def extract_bounds(value)
-            from, to = value[1..-2].split(',')
-            {
-              from:          (value[1] == ',' || from == '-infinity') ? @subtype.infinity(negative: true) : from,
-              to:            (value[-2] == ',' || to == 'infinity') ? @subtype.infinity : to,
-              exclude_start: (value[0] == '('),
-              exclude_end:   (value[-1] == ')')
-            }
-          end
-
-          def infinity?(value)
-            value.respond_to?(:infinite?) && value.infinite?
-          end
-
-          def type_cast_single(value)
-            infinity?(value) ? value : @subtype.type_cast(value)
-          end
-
-          def cast_value(value)
-            return if value == 'empty'
-            return value if value.is_a?(::Range)
-
-            extracted = extract_bounds(value)
-            from = type_cast_single extracted[:from]
-            to = type_cast_single extracted[:to]
-
-            if !infinity?(from) && extracted[:exclude_start]
-              if from.respond_to?(:succ)
-                from = from.succ
-                ActiveSupport::Deprecation.warn <<-MESSAGE
-Excluding the beginning of a Range is only partialy supported through `#succ`.
-This is not reliable and will be removed in the future.
-                MESSAGE
-              else
-                raise ArgumentError, "The Ruby Range object does not support excluding the beginning of a Range. (unsupported value: '#{value}')"
-              end
-            end
-            ::Range.new(from, to, extracted[:exclude_end])
-          end
-        end
-
-        class Integer < Type::Integer
-          include Infinity
-        end
-
-        class DateTime < Type::DateTime
-          include Infinity
-
-          def cast_value(value)
-            if value.is_a?(::String)
-              case value
-              when 'infinity' then ::Float::INFINITY
-              when '-infinity' then -::Float::INFINITY
-              when / BC$/
-                super("-" + value.sub(/ BC$/, ""))
-              else
-                super
-              end
-            else
-              value
-            end
-          end
-        end
-
-        class Date < Type::Date
-          include Infinity
-        end
-
-        class Time < Type::Time
-          include Infinity
-        end
-
-        class Float < Type::Float
-          include Infinity
-
-          def type_cast(value)
-            case value
-            when nil then         nil
-            when 'Infinity' then  ::Float::INFINITY
-            when '-Infinity' then -::Float::INFINITY
-            when 'NaN' then       ::Float::NAN
-            else                  value.to_f
-            end
-          end
-        end
-
-        class Decimal < Type::Decimal
-          def infinity(options = {})
-            BigDecimal.new("Infinity") * (options[:negative] ? -1 : 1)
-          end
-        end
-
-        class Enum < Type::Value
-          def type
-            :enum
-          end
-
-          def type_cast(value)
-            value.to_s
-          end
-        end
-
-        class Hstore < Type::Value
-          def type
-            :hstore
-          end
-
-          def type_cast_for_write(value)
-            ConnectionAdapters::PostgreSQLColumn.hstore_to_string value
-          end
-
-          def cast_value(value)
-            ConnectionAdapters::PostgreSQLColumn.string_to_hstore value
-          end
-
-          def accessor
-            ActiveRecord::Store::StringKeyedHashAccessor
-          end
-        end
-
-        class Cidr < Type::Value
-          def type
-            :cidr
-          end
-
-          def cast_value(value)
-            ConnectionAdapters::PostgreSQLColumn.string_to_cidr value
-          end
-        end
-
-        class Inet < Cidr
-          def type
-            :inet
-          end
-        end
-
-        class Json < Type::Value
-          def type
-            :json
-          end
-
-          def type_cast_for_write(value)
-            ConnectionAdapters::PostgreSQLColumn.json_to_string value
-          end
-
-          def cast_value(value)
-            ConnectionAdapters::PostgreSQLColumn.string_to_json value
-          end
-
-          def accessor
-            ActiveRecord::Store::StringKeyedHashAccessor
-          end
-        end
-
-        class Uuid < Type::Value
-          def type
-            :uuid
-          end
-
-          def type_cast(value)
-            value.presence
-          end
-        end
-
-        # This class uses the data from PostgreSQL pg_type table to build
-        # the OID -> Type mapping.
-        #   - OID is and integer representing the type.
-        #   - Type is an OID::Type object.
-        # This class has side effects on the +store+ passed during initialization.
-        class TypeMapInitializer # :nodoc:
-          def initialize(store)
-            @store = store
-          end
-
-          def run(records)
-            mapped, nodes = records.partition { |row| OID.registered_type? row['typname'] }
-            ranges, nodes = nodes.partition { |row| row['typtype'] == 'r' }
-            enums, nodes = nodes.partition { |row| row['typtype'] == 'e' }
-            domains, nodes = nodes.partition { |row| row['typtype'] == 'd' }
-            arrays, nodes = nodes.partition { |row| row['typinput'] == 'array_in' }
-            composites, nodes = nodes.partition { |row| row['typelem'] != '0' }
-
-            mapped.each     { |row| register_mapped_type(row)    }
-            enums.each      { |row| register_enum_type(row)      }
-            domains.each    { |row| register_domain_type(row)    }
-            arrays.each     { |row| register_array_type(row)     }
-            ranges.each     { |row| register_range_type(row)     }
-            composites.each { |row| register_composite_type(row) }
-          end
-
-          private
-          def register_mapped_type(row)
-            register row['oid'], OID::NAMES[row['typname']]
-          end
-
-          def register_enum_type(row)
-            register row['oid'], OID::Enum.new
-          end
-
-          def register_array_type(row)
-            if subtype = @store.lookup(row['typelem'].to_i)
-              register row['oid'], OID::Array.new(subtype)
-            end
-          end
-
-          def register_range_type(row)
-            if subtype = @store.lookup(row['rngsubtype'].to_i)
-              register row['oid'], OID::Range.new(subtype, row['typname'].to_sym)
-            end
-          end
-
-          def register_domain_type(row)
-            if base_type = @store.lookup(row["typbasetype"].to_i)
-              register row['oid'], base_type
-            else
-              warn "unknown base type (OID: #{row["typbasetype"]}) for domain #{row["typname"]}."
-            end
-          end
-
-          def register_composite_type(row)
-            if subtype = @store.lookup(row['typelem'].to_i)
-              register row['oid'], OID::Vector.new(row['typdelim'], subtype)
-            end
-          end
-
-          def register(oid, oid_type)
-            oid = oid.to_i
-
-            raise ArgumentError, "can't register nil type for OID #{oid}" if oid_type.nil?
-            return if @store.key?(oid)
-
-            @store.register_type(oid, oid_type)
-          end
-        end
-
         # When the PG adapter connects, the pg_type table is queried. The
         # key of this hash maps to the `typname` column from the table.
         # type_map is then dynamically built with oids as the key and type
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
new file mode 100644
index 0000000000..0e9dcd8c0c
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
@@ -0,0 +1,24 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Array < Type::Value
+          attr_reader :subtype
+          delegate :type, to: :subtype
+
+          def initialize(subtype)
+            @subtype = subtype
+          end
+
+          def type_cast(value)
+            if ::String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_array value, @subtype
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
new file mode 100644
index 0000000000..9b2d887d07
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Bit < Type::String
+          def type_cast(value)
+            if ::String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_bit value
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
new file mode 100644
index 0000000000..36c53d8732
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Bytea < Type::Binary
+          def cast_value(value)
+            PGconn.unescape_bytea value
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
new file mode 100644
index 0000000000..507c3a62b0
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Cidr < Type::Value
+          def type
+            :cidr
+          end
+
+          def cast_value(value)
+            ConnectionAdapters::PostgreSQLColumn.string_to_cidr value
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/date.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date.rb
new file mode 100644
index 0000000000..3c30ad5fec
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date.rb
@@ -0,0 +1,11 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Date < Type::Date
+          include Infinity
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
new file mode 100644
index 0000000000..9ccbf71159
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
@@ -0,0 +1,26 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class DateTime < Type::DateTime
+          include Infinity
+
+          def cast_value(value)
+            if value.is_a?(::String)
+              case value
+              when 'infinity' then ::Float::INFINITY
+              when '-infinity' then -::Float::INFINITY
+              when / BC$/
+                super("-" + value.sub(/ BC$/, ""))
+              else
+                super
+              end
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
new file mode 100644
index 0000000000..ed4b8911d9
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Decimal < Type::Decimal
+          def infinity(options = {})
+            BigDecimal.new("Infinity") * (options[:negative] ? -1 : 1)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
new file mode 100644
index 0000000000..5fed8b0f89
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Enum < Type::Value
+          def type
+            :enum
+          end
+
+          def type_cast(value)
+            value.to_s
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/float.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/float.rb
new file mode 100644
index 0000000000..9753d71461
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/float.rb
@@ -0,0 +1,21 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Float < Type::Float
+          include Infinity
+
+          def type_cast(value)
+            case value
+            when nil then         nil
+            when 'Infinity' then  ::Float::INFINITY
+            when '-Infinity' then -::Float::INFINITY
+            when 'NaN' then       ::Float::NAN
+            else                  value.to_f
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
new file mode 100644
index 0000000000..98f369a7f8
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
@@ -0,0 +1,25 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Hstore < Type::Value
+          def type
+            :hstore
+          end
+
+          def type_cast_for_write(value)
+            ConnectionAdapters::PostgreSQLColumn.hstore_to_string value
+          end
+
+          def cast_value(value)
+            ConnectionAdapters::PostgreSQLColumn.string_to_hstore value
+          end
+
+          def accessor
+            ActiveRecord::Store::StringKeyedHashAccessor
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
new file mode 100644
index 0000000000..7ed8f5f031
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Inet < Cidr
+          def type
+            :inet
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/infinity.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/infinity.rb
new file mode 100644
index 0000000000..d438ffa140
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/infinity.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        module Infinity
+          def infinity(options = {})
+            options[:negative] ? -::Float::INFINITY : ::Float::INFINITY
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/integer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/integer.rb
new file mode 100644
index 0000000000..388d3dd9ed
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/integer.rb
@@ -0,0 +1,11 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Integer < Type::Integer
+          include Infinity
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/json.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/json.rb
new file mode 100644
index 0000000000..42bf5656f4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/json.rb
@@ -0,0 +1,25 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Json < Type::Value
+          def type
+            :json
+          end
+
+          def type_cast_for_write(value)
+            ConnectionAdapters::PostgreSQLColumn.json_to_string value
+          end
+
+          def cast_value(value)
+            ConnectionAdapters::PostgreSQLColumn.string_to_json value
+          end
+
+          def accessor
+            ActiveRecord::Store::StringKeyedHashAccessor
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
new file mode 100644
index 0000000000..1e34c09c88
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
@@ -0,0 +1,37 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Money < Type::Decimal
+          include Infinity
+
+          def extract_scale(sql_type)
+            2
+          end
+
+          def cast_value(value)
+            return value unless ::String === value
+
+            # Because money output is formatted according to the locale, there are two
+            # cases to consider (note the decimal separators):
+            #  (1) $12,345,678.12
+            #  (2) $12.345.678,12
+            # Negative values are represented as follows:
+            #  (3) -$2.55
+            #  (4) ($2.55)
+
+            value.sub!(/^\((.+)\)$/, '-\1') # (4)
+            case value
+            when /^-?\D+[\d,]+\.\d{2}$/  # (1)
+              value.gsub!(/[^-\d.]/, '')
+            when /^-?\D+[\d.]+,\d{2}$/  # (2)
+              value.gsub!(/[^-\d,]/, '').sub!(/,/, '.')
+            end
+
+            super(value)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
new file mode 100644
index 0000000000..2769a8d3b4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Point < Type::String
+          def type_cast(value)
+            if ::String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_point value
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
new file mode 100644
index 0000000000..c2262c1599
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
@@ -0,0 +1,56 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Range < Type::Value
+          attr_reader :subtype, :type
+
+          def initialize(subtype, type)
+            @subtype = subtype
+            @type = type
+          end
+
+          def extract_bounds(value)
+            from, to = value[1..-2].split(',')
+            {
+              from:          (value[1] == ',' || from == '-infinity') ? @subtype.infinity(negative: true) : from,
+              to:            (value[-2] == ',' || to == 'infinity') ? @subtype.infinity : to,
+              exclude_start: (value[0] == '('),
+              exclude_end:   (value[-1] == ')')
+            }
+          end
+
+          def infinity?(value)
+            value.respond_to?(:infinite?) && value.infinite?
+          end
+
+          def type_cast_single(value)
+            infinity?(value) ? value : @subtype.type_cast(value)
+          end
+
+          def cast_value(value)
+            return if value == 'empty'
+            return value if value.is_a?(::Range)
+
+            extracted = extract_bounds(value)
+            from = type_cast_single extracted[:from]
+            to = type_cast_single extracted[:to]
+
+            if !infinity?(from) && extracted[:exclude_start]
+              if from.respond_to?(:succ)
+                from = from.succ
+                ActiveSupport::Deprecation.warn <<-MESSAGE
+Excluding the beginning of a Range is only partialy supported through `#succ`.
+This is not reliable and will be removed in the future.
+                MESSAGE
+              else
+                raise ArgumentError, "The Ruby Range object does not support excluding the beginning of a Range. (unsupported value: '#{value}')"
+              end
+            end
+            ::Range.new(from, to, extracted[:exclude_end])
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
new file mode 100644
index 0000000000..7b1ca16bc4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
@@ -0,0 +1,19 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class SpecializedString < Type::String
+          attr_reader :type
+
+          def initialize(type)
+            @type = type
+          end
+
+          def text?
+            false
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/time.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/time.rb
new file mode 100644
index 0000000000..ea1f599b0f
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/time.rb
@@ -0,0 +1,11 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Time < Type::Time
+          include Infinity
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
new file mode 100644
index 0000000000..27829ae1a3
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
@@ -0,0 +1,78 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        # This class uses the data from PostgreSQL pg_type table to build
+        # the OID -> Type mapping.
+        #   - OID is and integer representing the type.
+        #   - Type is an OID::Type object.
+        # This class has side effects on the +store+ passed during initialization.
+        class TypeMapInitializer # :nodoc:
+          def initialize(store)
+            @store = store
+          end
+
+          def run(records)
+            mapped, nodes = records.partition { |row| OID.registered_type? row['typname'] }
+            ranges, nodes = nodes.partition { |row| row['typtype'] == 'r' }
+            enums, nodes = nodes.partition { |row| row['typtype'] == 'e' }
+            domains, nodes = nodes.partition { |row| row['typtype'] == 'd' }
+            arrays, nodes = nodes.partition { |row| row['typinput'] == 'array_in' }
+            composites, nodes = nodes.partition { |row| row['typelem'] != '0' }
+
+            mapped.each     { |row| register_mapped_type(row)    }
+            enums.each      { |row| register_enum_type(row)      }
+            domains.each    { |row| register_domain_type(row)    }
+            arrays.each     { |row| register_array_type(row)     }
+            ranges.each     { |row| register_range_type(row)     }
+            composites.each { |row| register_composite_type(row) }
+          end
+
+          private
+          def register_mapped_type(row)
+            register row['oid'], OID::NAMES[row['typname']]
+          end
+
+          def register_enum_type(row)
+            register row['oid'], OID::Enum.new
+          end
+
+          def register_array_type(row)
+            if subtype = @store.lookup(row['typelem'].to_i)
+              register row['oid'], OID::Array.new(subtype)
+            end
+          end
+
+          def register_range_type(row)
+            if subtype = @store.lookup(row['rngsubtype'].to_i)
+              register row['oid'], OID::Range.new(subtype, row['typname'].to_sym)
+            end
+          end
+
+          def register_domain_type(row)
+            if base_type = @store.lookup(row["typbasetype"].to_i)
+              register row['oid'], base_type
+            else
+              warn "unknown base type (OID: #{row["typbasetype"]}) for domain #{row["typname"]}."
+            end
+          end
+
+          def register_composite_type(row)
+            if subtype = @store.lookup(row['typelem'].to_i)
+              register row['oid'], OID::Vector.new(row['typdelim'], subtype)
+            end
+          end
+
+          def register(oid, oid_type)
+            oid = oid.to_i
+
+            raise ArgumentError, "can't register nil type for OID #{oid}" if oid_type.nil?
+            return if @store.key?(oid)
+
+            @store.register_type(oid, oid_type)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
new file mode 100644
index 0000000000..0ed5491887
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Uuid < Type::Value
+          def type
+            :uuid
+          end
+
+          def type_cast(value)
+            value.presence
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
new file mode 100644
index 0000000000..2f7d1be197
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
@@ -0,0 +1,26 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Vector < Type::Value
+          attr_reader :delim, :subtype
+
+          # +delim+ corresponds to the `typdelim` column in the pg_types
+          # table.  +subtype+ is derived from the `typelem` column in the
+          # pg_types table.
+          def initialize(delim, subtype)
+            @delim   = delim
+            @subtype = subtype
+          end
+
+          # FIXME: this should probably split on +delim+ and use +subtype+
+          # to cast the values.  Unfortunately, the current Rails behavior
+          # is to just return the string.
+          def type_cast(value)
+            value
+          end
+        end
+      end
+    end
+  end
+end