gen/midas.py

@@ -136,15 +136,6 @@ class ConstraintType:
     constraint: Expr
 
 
-class ComplexType:
-    members: list[MemberStmt]
-
-
-class ExtensionType:
-    base: Type
-    extension: ComplexType
-
-
 class FunctionType:
     params: ParamSpec
     returns: Type

midas/ast/midas.py

@@ -256,12 +256,6 @@ class Type(ABC):
         @abstractmethod
         def visit_constraint_type(self, type: ConstraintType) -> T: ...
 
-        @abstractmethod
-        def visit_complex_type(self, type: ComplexType) -> T: ...
-
-        @abstractmethod
-        def visit_extension_type(self, type: ExtensionType) -> T: ...
-
         @abstractmethod
         def visit_function_type(self, type: FunctionType) -> T: ...
 
@@ -295,23 +289,6 @@ class ConstraintType(Type):
         return visitor.visit_constraint_type(self)
 
 
-@dataclass(frozen=True)
-class ComplexType(Type):
-    members: list[MemberStmt]
-
-    def accept(self, visitor: Type.Visitor[T]) -> T:
-        return visitor.visit_complex_type(self)
-
-
-@dataclass(frozen=True)
-class ExtensionType(Type):
-    base: Type
-    extension: ComplexType
-
-    def accept(self, visitor: Type.Visitor[T]) -> T:
-        return visitor.visit_extension_type(self)
-
-
 @dataclass(frozen=True)
 class FunctionType(Type):
     params: ParamSpec

midas/ast/printer/midas.py

@@ -124,19 +124,6 @@ class MidasPrinter(
         res += " where " + type.constraint.accept(self)
         return res
 
-    def visit_complex_type(self, type: m.ComplexType) -> str:
-        res: str = "{\n"
-        self.level += 1
-        for member in type.members:
-            res += member.accept(self)
-            res += "\n"
-        self.level -= 1
-        res += self.indented("}")
-        return res
-
-    def visit_extension_type(self, type: m.ExtensionType) -> str:
-        return f"{type.base.accept(self)} & {type.extension.accept(self)}"
-
     def visit_function_type(self, type: m.FunctionType) -> str:
         spec: str = self._visit_param_spec(type.params)
         return f"fn {spec} -> {type.returns.accept(self)}"

midas/ast/printer/midas_ast.py

@@ -177,21 +177,6 @@ class MidasAstPrinter(
             with self._child_level(single=True):
                 type.constraint.accept(self)
 
-    def visit_complex_type(self, type: m.ComplexType) -> None:
-        self._write_line("ComplexType")
-        with self._child_level():
-            self._write_sequence("members", type.members, last=True)
-
-    def visit_extension_type(self, type: m.ExtensionType) -> None:
-        self._write_line("ExtensionType")
-        with self._child_level():
-            self._write_line("base")
-            with self._child_level(single=True):
-                type.base.accept(self)
-            self._write_line("extension", last=True)
-            with self._child_level(single=True):
-                type.extension.accept(self)
-
     def visit_function_type(self, type: m.FunctionType) -> None:
         self._write_line("FunctionType")
         with self._child_level():

midas/checker/midas.py

@@ -13,11 +13,9 @@ from midas.checker.registry import TypesRegistry
 from midas.checker.reporter import FileReporter, Reporter
 from midas.checker.types import (
     ColumnType,
-    ComplexType,
     ConstraintType,
     DataFrameType,
     DerivedType,
-    ExtensionType,
     Function,
     GenericType,
     ParamSpec,
@@ -422,19 +420,6 @@ class MidasTyper(m.Stmt.Visitor[None], m.Expr.Visitor[Type], m.Type.Visitor[Type
             constraint=type.constraint,
         )
 
-    def visit_complex_type(self, type: m.ComplexType) -> ComplexType:
-        return ComplexType(
-            members={
-                member.name.lexeme: member.type.accept(self) for member in type.members
-            }
-        )
-
-    def visit_extension_type(self, type: m.ExtensionType) -> Type:
-        return ExtensionType(
-            base=type.base.accept(self),
-            extension=self.visit_complex_type(type.extension),
-        )
-
     def visit_function_type(self, type: m.FunctionType) -> Type:
         return Function(
             params=self._visit_param_spec(type.params),

midas/checker/registry.py

@@ -8,11 +8,9 @@ from midas.checker.types import (
     AppliedType,
     BaseType,
     ColumnType,
-    ComplexType,
     ConstraintType,
     DataFrameType,
     DerivedType,
-    ExtensionType,
     Function,
     GenericType,
     OverloadedFunction,
@@ -202,14 +200,6 @@ class TypesRegistry:
             case (BaseType(name=name1), BaseType(name=name2)):
                 return self.is_builtin_subtype(name1, name2)
 
-            case (ComplexType(properties=props1), ComplexType(properties=props2)):
-                for k, t in props2.items():
-                    if k not in props1:
-                        return False
-                    if not self.is_subtype(props1[k], t):
-                        return False
-                return True
-
             case (DataFrameType(columns=columns1), DataFrameType(columns=columns2)):
                 # TODO: check order?
                 by_name1: dict[str, DataFrameType.Column] = {
@@ -506,20 +496,6 @@ class TypesRegistry:
                     member_type2 = substitute_typevars(member_type2, substitutions)
                 return member_type2
 
-            case ComplexType(members=members):
-                if member_name in members:
-                    return members[member_name]
-                self.logger.debug(f"No member '{member_name}' in {type}")
-                return None
-
-            case ExtensionType(base=base, extension=ComplexType(members=members)):
-                if member_name in members:
-                    return members[member_name]
-                self.logger.debug(
-                    f"No member '{member_name}' on {type}, looking up in base"
-                )
-                return self.lookup_member(base, member_name)
-
             case ConstraintType(type=base):
                 return self.lookup_member(base, member_name)
 

midas/checker/types.py

@@ -113,28 +113,6 @@ class OverloadedFunction:
         return "<overloaded function>"
 
 
-@dataclass(frozen=True, kw_only=True)
-class ComplexType:
-    """A type with inline members"""
-
-    members: dict[str, Type]
-
-    def __str__(self) -> str:
-        props: list[str] = [f"{name}: {type}" for name, type in self.members.items()]
-        return f"{{{', '.join(props)}}}"
-
-
-@dataclass(frozen=True, kw_only=True)
-class ExtensionType:
-    """An extension of a type, adding members through a `ComplexType`"""
-
-    base: Type
-    extension: ComplexType
-
-    def __str__(self) -> str:
-        return f"{self.base} & {self.extension}"
-
-
 class Variance(StrEnum):
     """The variance of a :class:`TypeVar`"""
 
@@ -323,24 +301,6 @@ def substitute_typevars(type: Type, substitutions: dict[str, Type]) -> Type:
                 ]
             )
 
-        case ComplexType(members=members):
-            members2: dict[str, Type] = {
-                name: substitute_typevars(prop, substitutions)
-                for name, prop in members.items()
-            }
-            return ComplexType(members=members2)
-
-        case ExtensionType(base=base, extension=ComplexType(members=members)):
-            return ExtensionType(
-                base=substitute_typevars(base, substitutions),
-                extension=ComplexType(
-                    members={
-                        name: substitute_typevars(prop, substitutions)
-                        for name, prop in members.items()
-                    }
-                ),
-            )
-
         case AppliedType(name=name, args=args, body=body):
             return AppliedType(
                 name=name,
@@ -468,9 +428,6 @@ def to_annotation(type: Type) -> str:
         case OverloadedFunction():
             return "Callable"
 
-        case ComplexType() | ExtensionType():
-            raise NotImplementedError
-
         case TypeVar(name=name):
             return name
 
@@ -519,8 +476,6 @@ Type = (
     | UnitType
     | Function
     | OverloadedFunction
-    | ComplexType
-    | ExtensionType
     | TypeVar
     | GenericType
     | AppliedType

midas/cli/highlighter.py

@@ -338,21 +338,11 @@ class MidasHighlighter(
         type.type.accept(self)
         type.constraint.accept(self)
 
-    def visit_complex_type(self, type: m.ComplexType) -> None:
-        self.wrap(type, "complex-type")
-        for member in type.members:
-            member.accept(self)
-
     def visit_function_type(self, type: m.FunctionType) -> None:
         self.wrap(type, "function")
         self._visit_param_spec(type.params)
         type.returns.accept(self)
 
-    def visit_extension_type(self, type: m.ExtensionType) -> None:
-        self.wrap(type, "extension")
-        type.base.accept(self)
-        type.extension.accept(self)
-
     def _visit_param_spec(self, spec: m.ParamSpec) -> None:
         for param in spec.pos + spec.mixed + spec.kw:
             param.type.accept(self)

midas/cli/hl_midas.css

@@ -7,8 +7,7 @@ span {
 
     &.named-type,
     &.generic-type,
-    &.constraint-type,
+    &.constraint-type {
-    &.complex-type {
         --col: 150, 150, 150;
     }
 

midas/generator/generator.py

@@ -16,11 +16,9 @@ from midas.checker.types import (
     BaseType,
     ColumnGroupBy,
     ColumnType,
-    ComplexType,
     ConstraintType,
     DataFrameType,
     DerivedType,
-    ExtensionType,
     FrameGroupBy,
     Function,
     GenericType,
@@ -675,8 +673,6 @@ class Generator(p.Stmt.Visitor[ast.stmt], p.Expr.Visitor[ast.expr]):
             case (
                 Function()
                 | OverloadedFunction()
-                | ComplexType()
-                | ExtensionType()
                 | GenericType()
                 | FrameGroupBy()
                 | ColumnGroupBy()

midas/generator/stubs.py

@@ -8,11 +8,9 @@ from midas.checker.types import (
     BaseType,
     ColumnGroupBy,
     ColumnType,
-    ComplexType,
     ConstraintType,
     DataFrameType,
     DerivedType,
-    ExtensionType,
     FrameGroupBy,
     Function,
     GenericType,
@@ -269,14 +267,6 @@ class StubsGenerator:
                     right=self.dump_type(overloads[-1]),
                 )
 
-            case ComplexType():
-                name: str = self.new_stub_name()
-                self.generate_stub(name, type)
-                return ast.Name(id=name)
-
-            case ExtensionType():
-                raise NotImplementedError
-
             case TypeVar():
                 return ast.Name(id=type.name)
 

midas/parser/midas.py

@@ -5,11 +5,9 @@ from midas.ast.midas import (
     AliasStmt,
     BinaryExpr,
     CallExpr,
-    ComplexType,
     ConstraintType,
     Expr,
     ExtendStmt,
-    ExtensionType,
     FrameType,
     FunctionType,
     GenericType,
@@ -187,19 +185,9 @@ class MidasParser(Parser[list[Stmt]]):
         Returns:
             TypeExpr: the parsed type expression
         """
-        base: Type
         if self.match(TokenType.FUNC):
-            base = self.function()
+            return self.function()
-        else:
+        return self.constraint_type()
-            base = self.constraint_type()
-        if self.match(TokenType.AND):
-            extension: ComplexType = self.complex_type()
-            return ExtensionType(
-                location=Location.span(base.location, extension.location),
-                base=base,
-                extension=extension,
-            )
-        return base
 
     def constraint_type(self) -> Type:
         """Parse a constraint type expression
@@ -235,9 +223,6 @@ class MidasParser(Parser[list[Stmt]]):
             self.consume(TokenType.RIGHT_PAREN, "Unclosed parenthesis")
             return type
 
-        if self.check(TokenType.LEFT_BRACE):
-            return self.complex_type()
-
         return self.generic_type()
 
     def generic_type(self) -> Type:
@@ -295,34 +280,6 @@ class MidasParser(Parser[list[Stmt]]):
             name=name,
         )
 
-    def complex_type(self) -> ComplexType:
-        """Parse a complex type expression
-
-        A complex type consists of zero or more member statements enclosed in
-        curly braces
-
-        Returns:
-            ComplexType: the parsed complex type expression
-        """
-        left: Token = self.consume(
-            TokenType.LEFT_BRACE, "Expected '{' to start type body"
-        )
-        members: list[MemberStmt] = []
-        # TODO: add keyword to differentiate properties and methods,
-        # and allow multiple methods with the same name but not properties
-        names: set[str] = set()
-        while not self.check(TokenType.RIGHT_BRACE) and not self.is_at_end():
-            member: MemberStmt = self.member_stmt()
-            # if member.name.lexeme in names:
-            #    raise self.error(member.name, "Duplicate property")
-            # names.add(member.name.lexeme)
-            members.append(member)
-        right: Token = self.consume(TokenType.RIGHT_BRACE, "Unclosed type body")
-        return ComplexType(
-            location=left.location_to(right),
-            members=members,
-        )
-
     def frame_type(self) -> FrameType:
         """Parse a frame type expression
 

syntax/midas.ebnf

@@ -66,15 +66,13 @@ Params ::= (
 )
 ParamSpec ::= "(" Params? ")"
 
-TypeProperty ::= Identifier ":" Type
-ComplexType ::= "{" TypeProperty* "}"
 NamedType ::= Identifier
 TypeArgs ::= "[" (Type ("," Type)*)? "]"
 FrameColumn ::= TOKEN ":" Type
 FrameSchema ::= "[" (FrameColumn ("," FrameColumn)*)? "]"
 GenericType ::= "Frame" FrameSchema | NamedType TypeArgs?
 GroupedType ::= "(" Type ")"
-BaseType ::= GroupedType | ComplexType | GenericType
+BaseType ::= GroupedType | GenericType
 ConstraintType ::= BaseType ("where" Constraint)?
 FuncType ::= "fn" ParamSpec "->" Type
 Type ::= ConstraintType

syntax/midas.typ

@@ -72,14 +72,6 @@ svg.railroad .terminal rect {
 {[`template` "[" <!, 'template-param'*","> "]"]}
 ```
 
-#let type-property = ```
-{[`type-property` 'identifier' ":" 'type']}
-```
-
-#let complex-type = ```
-{[`complex-type` "{" <!, 'type-property'*!> "}"]}
-```
-
 #let named-type = ```
 {[`named-type` 'identifier']}
 ```
@@ -101,7 +93,7 @@ svg.railroad .terminal rect {
 ```
 
 #let base-type = ```
-{[`base-type` <'grouped-type', 'complex-type', 'generic-type'>]}
+{[`base-type` <'grouped-type', 'generic-type'>]}
 ```
 
 #let constraint-type = ```
@@ -169,7 +161,6 @@ svg.railroad .terminal rect {
   template-param: template-param,
   template: template,
   type-property: type-property,
-  complex-type: complex-type,
   named-type: named-type,
   type-args: type-args,
   generic-type: generic-type,
@@ -196,7 +187,6 @@ svg.railroad .terminal rect {
   "template",
   "type-property",
   "call-args",
-  "complex-type",
   "type-args",
   "named-type",
   "grouped-type",

tests/cases/checker/09_frame_ops.py

@@ -1,8 +1,8 @@
 # type: ignore
 # ruff: disable [F821]
 
-df1: Frame[a:int, b:float]
+df1: Frame[i:int, a:int, b:float]
-df2: Frame[a:int, b:float]
+df2: Frame[i:int, a:int, b:float]
 
 _: Any
 
@@ -38,7 +38,7 @@ _ = df1.sum()
 _ = df1.var()
 
 # Groupby
-df_gb = df1.groupby(by="a")
+df_gb = df1.groupby(by="i")
 
 _ = df_gb.kurt()
 _ = df_gb.max()

tests/cases/midas-parser/01_simple_types.midas

@@ -9,26 +9,22 @@ type Longitude = float where (-180 <= _ <= 180)
 type Difference[T] = T
 
 // Complex custom type, containing two values accessible through properties
-type GeoLocation = {
+type GeoLocation = object
+
+extend GeoLocation {
     prop lat: Latitude
     prop lon: Longitude
 }
 
-// Define operations on our custom type
+type GeoLocationDifference = object
-extend GeoLocation {
-    // This type is compatible with the `-` operation with another GeoLocation
-    // i.e. you can subtract a GeoLocation from another GeoLocation, resulting
-    // in a Difference of GeoLocations
-    def __sub__: fn(GeoLocation, /) -> Difference[GeoLocation]
-}
 
-// For complex generics, you need to specify how the genericity the properties
+extend GeoLocationDifference {
-// are handled
-type Difference[GeoLocation] = {
     prop lat: Difference[Latitude]
     prop lon: Difference[Longitude]
 }
 
+// Define operations on our custom type
+
 // Simple operation defined on our custom types
 extend Latitude {
     def __sub__: fn(Latitude, /) -> Difference[Latitude]
@@ -38,13 +34,23 @@ extend Longitude {
     def __sub__: fn(Longitude, /) -> Difference[Longitude]
 }
 
+extend GeoLocation {
+    // This type is compatible with the `-` operation with another GeoLocation
+    // i.e. you can subtract a GeoLocation from another GeoLocation, resulting
+    // in a GeoLocationDifference
+    def __sub__: fn(GeoLocation, /) -> GeoLocationDifference
+}
+
+
 // Predefined custom predicates that can be referenced in other definitions
 predicate Positive(v: float) = v >= 0
 predicate StrictlyPositive(v: float) = v > 0
 predicate Equatorial(loc: GeoLocation) = (-10 <= loc.lat <= 10)
 predicate Arctic(loc: GeoLocation) = (loc.lat >= 66)
 
-type Person = {
+type Person = object
+
+extend Person {
     prop name: str
 
     // Property with an inline constraint

tests/serializer/midas.py

@@ -4,11 +4,9 @@ from midas.ast.midas import (
     AliasStmt,
     BinaryExpr,
     CallExpr,
-    ComplexType,
     ConstraintType,
     Expr,
     ExtendStmt,
-    ExtensionType,
     FrameType,
     FunctionType,
     GenericType,
@@ -172,12 +170,6 @@ class MidasAstJsonSerializer(
             "constraint": type.constraint.accept(self),
         }
 
-    def visit_complex_type(self, type: ComplexType) -> dict:
-        return {
-            "_type": "ComplexType",
-            "members": self._serialize_list(type.members),
-        }
-
     def visit_function_type(self, type: FunctionType) -> dict:
         return {
             "_type": "FunctionType",
@@ -200,13 +192,6 @@ class MidasAstJsonSerializer(
             "required": param.required,
         }
 
-    def visit_extension_type(self, type: ExtensionType) -> dict:
-        return {
-            "_type": "ExtensionType",
-            "base": type.base.accept(self),
-            "extension": type.extension.accept(self),
-        }
-
     def visit_frame_type(self, type: FrameType) -> dict:
         return {
             "_type": "FrameType",