feat(checker): handle unary operations

examples/01_simple_type_checking/01_simple_operations.py

@@ -9,3 +9,5 @@ d = True
 e = d + d
 
 f: float = a
+
+f = -f

examples/01_simple_type_checking/02_simple_types.midas

@@ -3,12 +3,12 @@ type Second = float
 type MeterPerSecond = float
 
 extend Meter {
-    op __add__(Meter) -> Meter
+    def __add__: fn(Meter, /) -> Meter
-    op __sub__(Meter) -> Meter
+    def __sub__: fn(Meter, /) -> Meter
-    op __truediv__(Second) -> MeterPerSecond
+    def __truediv__: fn(Second, /) -> MeterPerSecond
 }
 
 extend Second {
-    op __add__(Second) -> Second
+    def __add__: fn(Second, /) -> Second
-    op __sub__(Second) -> Second
+    def __sub__: fn(Second, /) -> Second
 }

midas/checker/midas.py

@@ -105,24 +105,32 @@ class MidasTyper(m.Stmt.Visitor[None], m.Expr.Visitor[None], m.Type.Visitor[Type
                 member.kind == m.MemberKind.METHOD,
             )
 
-    def visit_predicate_stmt(self, stmt: m.PredicateStmt) -> None: ...
+    def visit_predicate_stmt(self, stmt: m.PredicateStmt) -> None:
+        self.reporter.warning(stmt.location, "PredicateStmt not yet supported")
 
-    def visit_logical_expr(self, expr: m.LogicalExpr) -> None: ...
+    def visit_logical_expr(self, expr: m.LogicalExpr) -> None:
+        self.reporter.warning(expr.location, "LogicalExpr not yet supported")
 
-    def visit_binary_expr(self, expr: m.BinaryExpr) -> None: ...
+    def visit_binary_expr(self, expr: m.BinaryExpr) -> None:
+        self.reporter.warning(expr.location, "BinaryExpr not yet supported")
 
-    def visit_unary_expr(self, expr: m.UnaryExpr) -> None: ...
+    def visit_unary_expr(self, expr: m.UnaryExpr) -> None:
+        self.reporter.warning(expr.location, "UnaryExpr not yet supported")
 
-    def visit_get_expr(self, expr: m.GetExpr) -> None: ...
+    def visit_get_expr(self, expr: m.GetExpr) -> None:
+        self.reporter.warning(expr.location, "GetExpr not yet supported")
 
-    def visit_variable_expr(self, expr: m.VariableExpr) -> None: ...
+    def visit_variable_expr(self, expr: m.VariableExpr) -> None:
+        self.reporter.warning(expr.location, "VariableExpr not yet supported")
 
     def visit_grouping_expr(self, expr: m.GroupingExpr) -> None:
         return expr.expr.accept(self)
 
-    def visit_literal_expr(self, expr: m.LiteralExpr) -> None: ...
+    def visit_literal_expr(self, expr: m.LiteralExpr) -> None:
+        self.reporter.warning(expr.location, "LiteralExpr not yet supported")
 
-    def visit_wildcard_expr(self, expr: m.WildcardExpr) -> None: ...
+    def visit_wildcard_expr(self, expr: m.WildcardExpr) -> None:
+        self.reporter.warning(expr.location, "WildcardExpr not yet supported")
 
     def visit_named_type(self, type: m.NamedType) -> Type:
         name: str = type.name.lexeme

midas/checker/operators.py

@@ -29,3 +29,10 @@ COMPARATOR_METHODS: dict[Type[ast.cmpop], str] = {
     # ast.In: "__in__",
     # ast.NotIn: "__notin__",
 }
+
+UNARY_METHODS: dict[Type[ast.unaryop], str] = {
+    ast.Invert: "__invert__",
+    # ast.Not: "",
+    ast.UAdd: "__pos__",
+    ast.USub: "__neg__",
+}

midas/checker/python.py

@@ -6,7 +6,7 @@ from typing import Optional
 import midas.ast.python as p
 from midas.ast.location import Location
 from midas.checker.environment import Environment
-from midas.checker.operators import COMPARATOR_METHODS, OPERATOR_METHODS
+from midas.checker.operators import COMPARATOR_METHODS, OPERATOR_METHODS, UNARY_METHODS
 from midas.checker.registry import TypesRegistry
 from midas.checker.reporter import FileReporter, Reporter
 from midas.checker.resolver import Resolver
@@ -375,7 +375,38 @@ class PythonTyper(
                 self.reporter.warning(location, f"Unsupported operation {operation}")
                 return UnknownType()
 
-    def visit_unary_expr(self, expr: p.UnaryExpr) -> Type: ...
+    def visit_unary_expr(self, expr: p.UnaryExpr) -> Type:
+        method: Optional[str] = UNARY_METHODS.get(expr.operator.__class__)
+        if method is None:
+            self.logger.warning(f"Unsupported operator {expr.operator}")
+            self.reporter.warning(
+                expr.location, f"Unsupported operator {expr.operator}"
+            )
+            return UnknownType()
+
+        operand: Type = self.type_of(expr.right)
+        operation: Optional[Type] = self.types.lookup_member(operand, method)
+        if operation is None:
+            self.reporter.error(
+                expr.location,
+                f"Undefined operation {method} for {operand}",
+            )
+            return UnknownType()
+
+        match operation:
+            case Function() as function:
+                if not self._is_unary_function(function):
+                    self.reporter.error(
+                        expr.location,
+                        f"Wrong definition of unary operation. Expected function with 0 parameters, got {function}",
+                    )
+                    return UnknownType()
+                return function.returns
+            case _:
+                self.reporter.warning(
+                    expr.location, f"Unsupported operation {operation}"
+                )
+                return UnknownType()
 
     def visit_call_expr(self, expr: p.CallExpr) -> Type:
         callee: Type = self.type_of(expr.callee)
@@ -494,11 +525,17 @@ class PythonTyper(
             return self.types.apply_generic(base, [param])
         return base
 
-    def visit_constraint_type(self, node: p.ConstraintType) -> Type: ...
+    def visit_constraint_type(self, node: p.ConstraintType) -> Type:
+        self.reporter.warning(node.location, "ConstraintType not yet supported")
+        return UnknownType()
 
-    def visit_frame_column(self, node: p.FrameColumn) -> Type: ...
+    def visit_frame_column(self, node: p.FrameColumn) -> Type:
+        self.reporter.warning(node.location, "FrameColumn not yet supported")
+        return UnknownType()
 
-    def visit_frame_type(self, node: p.FrameType) -> Type: ...
+    def visit_frame_type(self, node: p.FrameType) -> Type:
+        self.reporter.warning(node.location, "FrameType not yet supported")
+        return UnknownType()
 
     def map_call_arguments(
         self, function: Function, call: p.CallExpr
@@ -625,3 +662,12 @@ class PythonTyper(
         if len(function.kw_args) != 0:
             return False
         return True
+
+    def _is_unary_function(self, function: Function) -> bool:
+        if len(function.pos_args) != 0:
+            return False
+        if len(function.args) != 0:
+            return False
+        if len(function.kw_args) != 0:
+            return False
+        return True