#5 remove read_object. allow read / read? to receive any type

src/db/result_set.cr

@@ -16,14 +16,10 @@ module DB
   # ### Note to implementors
   #
   # 1. Override `#move_next` to move to the next row.
-  # 2. Override `#read?(t)` for all `t` in `DB::TYPES`.
-  # 3. (Optional) Override `#read(t)` for all `t` in `DB::TYPES`.
+  # 2. Override `#read?(t)` for all `t` in `DB::TYPES` and any other types the driver should handle.
+  # 3. (Optional) Override `#read(t)` for all `t` in `DB::TYPES` and any other.
   # 4. Override `#column_count`, `#column_name`.
   # 5. Override `#column_type`. It must return a type in `DB::TYPES`.
-  # 6. Override `#read_object` to return other data types not included in `DB::TYPES`. This
-  #    will create a union type, so user will be forced to cast result type. Usually `#read`
-  #    should be used to avoid unnecesary intermediate union type values. Calling `#read_object`
-  #    should also move to the next column.
   abstract class ResultSet
     include Disposable
 
@@ -63,28 +59,26 @@ module DB
     # The result is one of `DB::TYPES`.
     abstract def column_type(index : Int32)
 
-    # list datatypes that must be supported form the driver
-    # users will call read(String) or read?(String) for nillables
-
-    {% for t in DB::TYPES %}
-      # Reads the next column as a nillable {{t}}.
-      abstract def read?(t : {{t}}.class) : {{t}}?
-
-      # Reads the next column as a {{t}}.
-      def read(t : {{t}}.class) : {{t}}
-        read?({{t}}).not_nil!
-      end
-    {% end %}
+    def read(t)
+      read?(t).not_nil!
+    end
 
     # Reads the next column as a Nil.
     def read(t : Nil.class) : Nil
       read?(Nil)
     end
 
-    def read_object
-      raise "Not implemented"
+    def read?(t)
+      raise "read?(t : #{t}) is not implemented in #{self.class}"
     end
 
+    # list datatypes that must be supported form the driver
+    # users will call read(String) or read?(String) for nillables
+    {% for t in DB::TYPES %}
+      # Reads the next column as a nillable {{t}}.
+      abstract def read?(t : {{t}}.class) : {{t}}?
+    {% end %}
+
     # def read_blob
     #   yield ... io ....
     # end