From 9f05ba3224722ce7579919154ead4e8b6e612f4b Mon Sep 17 00:00:00 2001
From: LordBaryhobal <lordbaryhobal@gmail.com>
Date: Wed, 24 Jun 2026 13:51:01 +0200
Subject: [PATCH] feat: handle unsafe casts

---
 gen/python.py                                   | 1 +
 midas/ast/printer.py                            | 3 ++-
 midas/ast/python.py                             | 1 +
 midas/generator/generator.py                    | 2 +-
 midas/parser/python.py                          | 9 ++++++++-
 tests/cases/checker/04_custom_types.py.ref.json | 6 ++++--
 tests/serializer/python.py                      | 1 +
 7 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/gen/python.py b/gen/python.py
index 4af901a..df83e6f 100644
--- a/gen/python.py
+++ b/gen/python.py
@@ -145,6 +145,7 @@ class LogicalExpr:
 class CastExpr:
     type: MidasType
     expr: Expr
+    unsafe: bool
 
 
 class TernaryExpr:
diff --git a/midas/ast/printer.py b/midas/ast/printer.py
index 1c75a44..680fd79 100644
--- a/midas/ast/printer.py
+++ b/midas/ast/printer.py
@@ -757,9 +757,10 @@ class PythonAstPrinter(
             self._write_line("type")
             with self._child_level(single=True):
                 expr.type.accept(self)
-            self._write_line("expr", last=True)
+            self._write_line("expr")
             with self._child_level(single=True):
                 expr.expr.accept(self)
+            self._write_line(f"unsafe: {expr.unsafe}", last=True)
 
     def visit_ternary_expr(self, expr: p.TernaryExpr) -> None:
         self._write_line("TernaryExpr")
diff --git a/midas/ast/python.py b/midas/ast/python.py
index 7770de6..20d7279 100644
--- a/midas/ast/python.py
+++ b/midas/ast/python.py
@@ -350,6 +350,7 @@ class LogicalExpr(Expr):
 class CastExpr(Expr):
     type: MidasType
     expr: Expr
+    unsafe: bool
 
     def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_cast_expr(self)
diff --git a/midas/generator/generator.py b/midas/generator/generator.py
index 0fba91e..0af3fcd 100644
--- a/midas/generator/generator.py
+++ b/midas/generator/generator.py
@@ -133,7 +133,7 @@ class Generator(p.Stmt.Visitor[ast.stmt], p.Expr.Visitor[ast.expr]):
     def visit_cast_expr(self, expr: p.CastExpr) -> ast.expr:
         expr2: ast.expr = expr.expr.accept(self)
 
-        if expr in self._typed_ast.evaluated_casts:
+        if expr in self._typed_ast.evaluated_casts or expr.unsafe:
             return expr2
 
         alias: ast.expr = self._make_alias(expr2)
diff --git a/midas/parser/python.py b/midas/parser/python.py
index 4110feb..7839f52 100644
--- a/midas/parser/python.py
+++ b/midas/parser/python.py
@@ -49,6 +49,7 @@ class UnsupportedSyntaxError(Exception):
 
 class PythonParser:
     CAST_FUNCTION = "cast"
+    UNSAFE_CAST_FUNCTION = "unsafe_cast"
 
     def parse_module(self, node: ast.Module) -> list[Stmt]:
         statements: list[Stmt] = []
@@ -423,6 +424,9 @@ class PythonParser:
             case ast.Call(func=ast.Name(id=self.CAST_FUNCTION)):
                 return self.parse_cast(node)
 
+            case ast.Call(func=ast.Name(id=self.UNSAFE_CAST_FUNCTION)):
+                return self.parse_cast(node)
+
             case ast.Call():
                 return self.parse_call(node)
 
@@ -527,16 +531,19 @@ class PythonParser:
         return expr
 
     def parse_cast(self, node: ast.Call) -> CastExpr:
+        assert isinstance(node.func, ast.Name)
+        func: str = node.func.id
         match node:
             case ast.Call(args=[type, expr], keywords=[]):
                 return CastExpr(
                     location=Location.from_ast(node),
                     type=self._parse_type(type),
                     expr=self.parse_expr(expr),
+                    unsafe=func == self.UNSAFE_CAST_FUNCTION,
                 )
             case _:
                 raise InvalidSyntaxError(
-                    f"Invalid call to {self.CAST_FUNCTION}, expected type and expression"
+                    f"Invalid call to {func}, expected type and expression"
                 )
 
     def parse_call(self, node: ast.Call) -> CallExpr:
diff --git a/tests/cases/checker/04_custom_types.py.ref.json b/tests/cases/checker/04_custom_types.py.ref.json
index d502a97..01177d9 100644
--- a/tests/cases/checker/04_custom_types.py.ref.json
+++ b/tests/cases/checker/04_custom_types.py.ref.json
@@ -29,7 +29,8 @@
         "expr": {
           "_type": "LiteralExpr",
           "value": 123.45
-        }
+        },
+        "unsafe": false
       },
       "type": {
         "name": "Meter",
@@ -66,7 +67,8 @@
         "expr": {
           "_type": "LiteralExpr",
           "value": 6.7
-        }
+        },
+        "unsafe": false
       },
       "type": {
         "name": "Second",
diff --git a/tests/serializer/python.py b/tests/serializer/python.py
index 038b496..3904739 100644
--- a/tests/serializer/python.py
+++ b/tests/serializer/python.py
@@ -263,6 +263,7 @@ class PythonAstJsonSerializer(
             "_type": "CastExpr",
             "type": expr.type.accept(self),
             "expr": expr.expr.accept(self),
+            "unsafe": expr.unsafe,
         }
 
     def visit_ternary_expr(self, expr: TernaryExpr) -> dict: