From 37a464d2bc7ea3f166b878c27121c191c8d655c9 Mon Sep 17 00:00:00 2001
From: LordBaryhobal <lordbaryhobal@gmail.com>
Date: Sun, 14 Jun 2026 16:58:20 +0200
Subject: [PATCH] feat(checker): type check slice expressions

---
 midas/checker/builtins.py | 1 +
 midas/checker/python.py   | 3 +++
 midas/checker/resolver.py | 8 ++++++++
 3 files changed, 12 insertions(+)

diff --git a/midas/checker/builtins.py b/midas/checker/builtins.py
index 961545a..b1adf6d 100644
--- a/midas/checker/builtins.py
+++ b/midas/checker/builtins.py
@@ -29,6 +29,7 @@ def define_builtins(reg: TypesRegistry):
     int = reg.define_type("int", BaseType(name="int"))
     float = reg.define_type("float", BaseType(name="float"))
     str = reg.define_type("str", BaseType(name="str"))
+    slice = reg.define_type("slice", BaseType(name="slice"))
 
     list = reg.define_type(
         "list",
diff --git a/midas/checker/python.py b/midas/checker/python.py
index 9ce9399..f28ce77 100644
--- a/midas/checker/python.py
+++ b/midas/checker/python.py
@@ -507,6 +507,9 @@ class PythonTyper(
             expr.location, operation, [(expr.index, index)], {}
         )
 
+    def visit_slice_expr(self, expr: p.SliceExpr) -> Type:
+        return self.types.get_type("slice")
+
     def visit_base_type(self, node: p.BaseType) -> Type:
         base: Type
         try:
diff --git a/midas/checker/resolver.py b/midas/checker/resolver.py
index 636ccfe..12f18cf 100644
--- a/midas/checker/resolver.py
+++ b/midas/checker/resolver.py
@@ -200,3 +200,11 @@ class Resolver(p.Stmt.Visitor[None], p.Expr.Visitor[None]):
     def visit_subscript_expr(self, expr: p.SubscriptExpr) -> None:
         self.resolve(expr.object)
         self.resolve(expr.index)
+
+    def visit_slice_expr(self, expr: p.SliceExpr) -> None:
+        if expr.lower is not None:
+            self.resolve(expr.lower)
+        if expr.upper is not None:
+            self.resolve(expr.upper)
+        if expr.step is not None:
+            self.resolve(expr.step)