Substitute abstract classes with type aliases

Author: GlassOfWhiskey

schema_salad/metaschema.py

@@ -24,7 +24,6 @@
 from urllib.parse import quote, urldefrag, urlparse, urlsplit, urlunsplit
 from urllib.request import pathname2url
 
-from mypy_extensions import trait
 from rdflib import Graph
 from rdflib.plugins.parsers.notation3 import BadSyntax
 from ruamel.yaml.comments import CommentedMap
@@ -214,7 +213,6 @@ def graph(self) -> Graph:
         return graph
 
 
-@trait
 class Saveable(metaclass=ABCMeta):
     """Mark classes than have a save() and fromDoc() function."""
 
@@ -1187,12 +1185,7 @@ def parser_info() -> str:
     return "org.w3id.cwl.salad"
 
 
-@trait
-class Documented(Saveable, metaclass=ABCMeta):
-    doc: None | Sequence[str] | str
-
-
-class RecordField(Documented):
+class RecordField(Saveable):
     """
     A field of a record.
     """
@@ -3480,35 +3473,11 @@ def __init__(
     attrs: ClassVar[Collection[str]] = frozenset(["specializeFrom", "specializeTo"])
 
 
-@trait
-class NamedType(Saveable, metaclass=ABCMeta):
-    name: str
-    inVocab: None | bool
-
-
-@trait
-class DocType(Documented, metaclass=ABCMeta):
-    doc: None | Sequence[str] | str
-    docParent: None | str
-    docChild: None | Sequence[str] | str
-    docAfter: None | str
-
-
-@trait
-class SchemaDefinedType(DocType, metaclass=ABCMeta):
     """
     Abstract base for schema-defined types.
 
     """
 
-    doc: None | Sequence[str] | str
-    docParent: None | str
-    docChild: None | Sequence[str] | str
-    docAfter: None | str
-    jsonldPredicate: JsonldPredicate | None | str
-    documentRoot: None | bool
-
-
 class SaladRecordField(RecordField):
     """
     A field of a record.
@@ -3898,7 +3867,7 @@ def __init__(
     )
 
 
-class SaladRecordSchema(NamedType, RecordSchema, SchemaDefinedType):
+class SaladRecordSchema(RecordSchema):
     name: str
 
     def __eq__(self, other: Any) -> bool:
@@ -4756,7 +4725,7 @@ def __init__(
     )
 
 
-class SaladEnumSchema(NamedType, EnumSchema, SchemaDefinedType):
+class SaladEnumSchema(EnumSchema):
     """
     Define an enumerated type.
 
@@ -5499,7 +5468,7 @@ def __init__(
     )
 
 
-class SaladMapSchema(NamedType, MapSchema, SchemaDefinedType):
+class SaladMapSchema(MapSchema):
     """
     Define a map type.
 
@@ -6186,7 +6155,7 @@ def __init__(
     )
 
 
-class SaladUnionSchema(NamedType, UnionSchema, DocType):
+class SaladUnionSchema(UnionSchema):
     """
     Define a union type.
 
@@ -6813,7 +6782,7 @@ def __init__(
     )
 
 
-class Documentation(NamedType, DocType):
+class Documentation(Saveable):
     """
     A documentation section.  This type exists to facilitate self-documenting
     schemas but has no role in formal validation.
@@ -7621,6 +7590,16 @@ def __init__(
     )
 )
 
+SchemaDefinedType: TypeAlias = SaladEnumSchema | SaladMapSchema | SaladRecordSchema
+NamedType: TypeAlias = (
+    Documentation
+    | SaladEnumSchema
+    | SaladMapSchema
+    | SaladRecordSchema
+    | SaladUnionSchema
+)
+DocType: TypeAlias = Documentation | SaladUnionSchema | SchemaDefinedType
+Documented: TypeAlias = DocType | RecordField
 
 def load_document(
     doc: Any,

schema_salad/python_codegen.py

@@ -2,6 +2,7 @@
 
 import textwrap
 from collections.abc import MutableSequence
+from graphlib import TopologicalSorter
 from io import StringIO
 from typing import IO, Any, Final
 
@@ -91,6 +92,7 @@ def __init__(
         self.copyright: Final = copyright
         self.parser_info: Final = parser_info
         self.salad_version: Final = salad_version
+        self.subclasses: dict[str, list[str]] = {}
 
     @staticmethod
     def safe_name(name: str) -> str:
@@ -148,18 +150,19 @@ def begin_class(
         self.current_fieldtypes: dict[str, TypeDef] = {}
         self.current_class_is_abstract = abstract
 
-        if extends:
-            ext = ", ".join(self.safe_name(e) for e in extends)
-        else:
-            ext = "Saveable"
-
         if self.current_class_is_abstract:
-            ext += ", metaclass=ABCMeta"
-            decorator = "@trait\n"
+            self.subclasses[classname] = []
         else:
-            decorator = ""
+            parents = [
+                self.safe_name(e) for e in extends if self.safe_name(e) not in self.subclasses
+            ]
+            ext = ", ".join(parents) if parents else "Saveable"
+            self.out.write(fmt(f"class {classname}({ext}):\n    pass", 0)[:-9])
+
+        for ext in extends:
+            if (safe_ext := self.safe_name(ext)) in self.subclasses:
+                self.subclasses[safe_ext].append(classname)
 
-        self.out.write(fmt(f"{decorator}class {classname}({ext}):\n    pass", 0)[:-9])
         # make a valid class for Black, but then trim off the "pass"
 
         if doc:
@@ -241,15 +244,6 @@ def save(
     def end_class(self, classname: str, field_names: list[str]) -> None:
         """Signal that we are done with this class."""
         if self.current_class_is_abstract:
-            if field_names:
-                for name in field_names:
-                    safename = self.safe_name(name)
-                    self.out.write(
-                        f"    {safename}: {self.current_fieldtypes[safename].instance_type}\n"
-                    )
-                self.out.write("\n\n")
-            else:
-                self.out.write("    pass\n\n\n")
             return
 
         self.out.write(
@@ -341,9 +335,7 @@ def end_class(self, classname: str, field_names: list[str]) -> None:
         for name in field_names:
             if name == "class":
                 field_inits += """        self.class_: Final[str] = "{}"
-""".format(
-                    self.safe_name(classname)
-                )
+""".format(self.safe_name(classname))
             elif name == idfield_safe_name and name in optional_field_names:
                 field_inits += (
                     "        self.{0}: str = {0} if {0} is not None else "
@@ -834,6 +826,15 @@ def epilogue(self, root_loader: TypeDef) -> None:
                 self.out.write(fmt(f"{lazy_init.instance_type}", 0))
             self.out.write("\n")
 
+        for class_ in TopologicalSorter(self.subclasses).static_order():
+            if self.subclasses.get(class_) is not None:
+                self.out.write(
+                    fmt(
+                        f"{class_}: TypeAlias = {' | '.join(sorted(self.subclasses[class_]))}",
+                        0,
+                    )
+                )
+
         self.out.write(
             """
 def load_document(

schema_salad/python_codegen_support.py

@@ -21,7 +21,6 @@
 from urllib.parse import quote, urldefrag, urlparse, urlsplit, urlunsplit
 from urllib.request import pathname2url
 
-from mypy_extensions import trait
 from rdflib import Graph
 from rdflib.plugins.parsers.notation3 import BadSyntax
 from ruamel.yaml.comments import CommentedMap
@@ -211,7 +210,6 @@ def graph(self) -> Graph:
         return graph
 
 
-@trait
 class Saveable(metaclass=ABCMeta):
     """Mark classes than have a save() and fromDoc() function."""
 

schema_salad/tests/test_python_codegen.py

@@ -28,7 +28,7 @@ def test_cwl_gen(tmp_path: Path) -> None:
     python_codegen(cwl_file_uri, src_target)
     assert os.path.exists(src_target)
     with open(src_target) as f:
-        assert "class Workflow(Process)" in f.read()
+        assert "class Workflow(Saveable)" in f.read()
 
 
 def test_meta_schema_gen(tmp_path: Path) -> None: