Generate __hash__ on python as well

src/Nirum/Targets/Python.hs

@@ -200,6 +200,12 @@ compileUnionTag source parentname typename' fields = do
         slots = if length tagNames == 1
                 then [qq|'{head tagNames}'|] `T.snoc` ','
                 else toIndentedCodes (\n -> [qq|'{n}'|]) tagNames ",\n        "
+        hashTuple = if null tagNames
+            then "self.__nirum_tag__"
+            else [qq|({attributes},)|] :: T.Text
+          where
+            attributes :: T.Text
+            attributes = toIndentedCodes (\n -> [qq|self.{n}|]) tagNames ", "
         initialArgs = toIndentedCodes
             (\(n, t) -> [qq|{n}: {t}|]) nameNTypes ", "
         initialValues =
@@ -244,6 +250,9 @@ class $className($parentClass):
             getattr(self, attr) == getattr(other, attr)
             for attr in self.__slots__
         )
+
+    def __hash__(self) -> int:
+        return hash($hashTuple)
             |]
 
 compilePrimitiveType :: PrimitiveTypeIdentifier -> CodeGen Code
@@ -338,6 +347,9 @@ class $className:
         return '\{0.__module__\}.\{0.__qualname__\}(\{1!r\})'.format(
             type(self), self.value
         )
+
+    def __hash__(self) -> int:
+        return hash(self.value)
             |]
 compileTypeDeclaration _ TypeDeclaration { typename = typename'
                                          , type' = EnumType members } = do
@@ -381,6 +393,9 @@ compileTypeDeclaration src TypeDeclaration { typename = typename'
             toNamePair
             [name | Field name _ _ <- toList fields]
             ",\n        "
+        hashTuple = [qq|({attributes},)|] :: T.Text
+          where
+            attributes = toIndentedCodes (\n -> [qq|self.{n}|]) fieldNames ","
     insertStandardImport "typing"
     insertThirdPartyImports [ ("nirum.validate", ["validate_record_type"])
                             , ("nirum.serialize", ["serialize_record_type"])
@@ -425,6 +440,9 @@ class $className:
     @classmethod
     def __nirum_deserialize__(cls: type, value) -> '{className}':
         return deserialize_record_type(cls, value)
+
+    def __hash__(self) -> int:
+        return hash($hashTuple)
                         |]
 compileTypeDeclaration src TypeDeclaration { typename = typename'
                                            , type' = UnionType tags } = do

test/Nirum/Targets/PythonSpec.hs

@@ -502,6 +502,8 @@ spec = parallel $ do
             tT decl "FloatBox(3.14).__nirum_serialize__() == 3.14"
             tT decl "FloatBox.__nirum_deserialize__(3.14) == FloatBox(3.14)"
             tT decl "FloatBox.__nirum_deserialize__(3.14) == FloatBox(3.14)"
+            tT decl "hash(FloatBox(3.14))"
+            tT decl "hash(FloatBox(3.14)) != 3.14"
             tR' decl "TypeError" "FloatBox.__nirum_deserialize__('a')"
             tR' decl "TypeError" "FloatBox('a')"
             let decls = [ Import ["foo", "bar"] "path-box" empty
@@ -596,6 +598,7 @@ spec = parallel $ do
             tT decl "Point(left=3, top=14) != Point(left=4, top=14)"
             tT decl "Point(left=3, top=14) != Point(left=4, top=15)"
             tT decl "Point(left=3, top=14) != 'foo'"
+            tT decl "hash(Point(left=3, top=14))"
             tT decl [q|Point(left=3, top=14).__nirum_serialize__() ==
                        {'_type': 'point', 'x': 3, 'top': 14}|]
             tT decl [qq|Point.__nirum_deserialize__($payload) ==
@@ -669,7 +672,7 @@ spec = parallel $ do
             tT decl "Line.__slots__ == ('length', )"
             tT decl [qq|Line(length=3).__nirum_serialize__() == $payload|]
         specify "union type" $ do
-            let wasternNameTag =
+            let westernNameTag =
                     Tag "western-name" [ Field "first-name" "text" empty
                                        , Field "middle-name" "text" empty
                                        , Field "last-name" "text" empty
@@ -682,7 +685,7 @@ spec = parallel $ do
                     Tag "culture-agnostic-name"
                         [ Field "fullname" "text" empty ]
                         empty
-                tags = [ wasternNameTag
+                tags = [ westernNameTag
                        , eastAsianNameTag
                        , cultureAgnosticNameTag
                        ]
@@ -733,6 +736,8 @@ spec = parallel $ do
                                    last_name='wrong') !=
                        WesternName(first_name='foo', middle_name='bar',
                                    last_name='baz')|]
+            tT decl [q|hash(WesternName(first_name='foo', middle_name='bar',
+                                        last_name='baz'))|]
             tT decl "isinstance(EastAsianName, type)"
             tT decl "issubclass(EastAsianName, Name)"
             tT decl [q|EastAsianName(family_name='foo',