From 01347ab7d79fda3afba8649de4602845e5be2398 Mon Sep 17 00:00:00 2001
From: whitingyan <1712428442@qq.com>
Date: Tue, 18 Mar 2025 13:13:36 +0800
Subject: [PATCH 1/2] init

---
 python/taichi/__init__.py                     |  2 ++
 python/taichi/lang/ast/ast_transformer.py     | 32 +++++++++++++------
 .../taichi/lang/ast/ast_transformer_utils.py  |  9 ++++--
 python/taichi/lang/ast/hint.py                |  5 +++
 4 files changed, 36 insertions(+), 12 deletions(-)
 create mode 100644 python/taichi/lang/ast/hint.py

diff --git a/python/taichi/__init__.py b/python/taichi/__init__.py
index 034052ed5bd73..0882b41aa3d93 100644
--- a/python/taichi/__init__.py
+++ b/python/taichi/__init__.py
@@ -16,6 +16,8 @@
 # Issue#2223: Do not reorder, or we're busted with partially initialized module
 from taichi import aot  # isort:skip
 
+from taichi.lang.ast.hint import new, hide
+
 
 def __getattr__(attr):
     if attr == "cfg":
diff --git a/python/taichi/lang/ast/ast_transformer.py b/python/taichi/lang/ast/ast_transformer.py
index ba7890d9b6b79..6a2fa6bef7ebc 100644
--- a/python/taichi/lang/ast/ast_transformer.py
+++ b/python/taichi/lang/ast/ast_transformer.py
@@ -16,6 +16,7 @@
 from taichi.lang._ndrange import _Ndrange, ndrange
 from taichi.lang.argpack import ArgPackType
 from taichi.lang.ast.ast_transformer_utils import Builder, LoopStatus, ReturnStatus
+from taichi.lang.ast import hint
 from taichi.lang.ast.symbol_resolver import ASTResolver
 from taichi.lang.exception import (
     TaichiIndexError,
@@ -105,18 +106,29 @@ def build_assign_annotated(ctx, target, value, is_static_assign, annotation):
                 f'Kernel argument "{target.id}" is immutable in the kernel. '
                 f"If you want to change its value, please create a new variable."
             )
-        anno = impl.expr_init(annotation)
-        if is_static_assign:
-            raise TaichiSyntaxError("Static assign cannot be used on annotated assignment")
-        if is_local and not ctx.is_var_declared(target.id):
-            var = ti_ops.cast(value, anno)
-            var = impl.expr_init(var)
+        if annotation is hint.new:
+            var = impl.expr_init(value)
             ctx.create_variable(target.id, var)
+        elif annotation is hint.hide:
+            var = impl.expr_init(value)
+            ctx.hide_variable(target.id, var)
         else:
-            var = build_stmt(ctx, target)
-            if var.ptr.get_rvalue_type() != anno:
-                raise TaichiSyntaxError("Static assign cannot have type overloading")
-            var._assign(value)
+            anno = impl.expr_init(annotation)
+            if is_static_assign:
+                raise TaichiSyntaxError(
+                    "Static assign cannot be used on annotated assignment"
+                )
+            if is_local and not ctx.is_var_declared(target.id):
+                var = ti_ops.cast(value, anno)
+                var = impl.expr_init(var)
+                ctx.create_variable(target.id, var)
+            else:
+                var = build_stmt(ctx, target)
+                if var.ptr.get_rvalue_type() != anno:
+                    raise TaichiSyntaxError(
+                        "Static assign cannot have type overloading"
+                    )
+                var._assign(value)
         return var
 
     @staticmethod
diff --git a/python/taichi/lang/ast/ast_transformer_utils.py b/python/taichi/lang/ast/ast_transformer_utils.py
index 4a10d5e3546c6..b3f96f32ea58b 100644
--- a/python/taichi/lang/ast/ast_transformer_utils.py
+++ b/python/taichi/lang/ast/ast_transformer_utils.py
@@ -240,10 +240,15 @@ def is_var_declared(self, name):
         return False
 
     def create_variable(self, name, var):
-        if name in self.current_scope():
-            raise TaichiSyntaxError("Recreating variables is not allowed")
+        # if name in self.current_scope():
+        #     raise TaichiSyntaxError("Recreating variables is not allowed")
         self.current_scope()[name] = var
 
+    def hide_variable(self, name, var):
+        for s in reversed(self.local_scopes):
+            if name in s:
+                s[name] = var
+
     def check_loop_var(self, loop_var):
         if self.is_var_declared(loop_var):
             raise TaichiSyntaxError(
diff --git a/python/taichi/lang/ast/hint.py b/python/taichi/lang/ast/hint.py
new file mode 100644
index 0000000000000..04731deaea97c
--- /dev/null
+++ b/python/taichi/lang/ast/hint.py
@@ -0,0 +1,5 @@
+from typing import Any
+
+
+type new = Any
+type hide = Any

From 7a08fb7bf1e2165b3c6377b5e8eb82094f410d22 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 18 Mar 2025 05:34:26 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 python/taichi/lang/ast/ast_transformer.py | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/python/taichi/lang/ast/ast_transformer.py b/python/taichi/lang/ast/ast_transformer.py
index 6a2fa6bef7ebc..8c3cfedd588a1 100644
--- a/python/taichi/lang/ast/ast_transformer.py
+++ b/python/taichi/lang/ast/ast_transformer.py
@@ -115,9 +115,7 @@ def build_assign_annotated(ctx, target, value, is_static_assign, annotation):
         else:
             anno = impl.expr_init(annotation)
             if is_static_assign:
-                raise TaichiSyntaxError(
-                    "Static assign cannot be used on annotated assignment"
-                )
+                raise TaichiSyntaxError("Static assign cannot be used on annotated assignment")
             if is_local and not ctx.is_var_declared(target.id):
                 var = ti_ops.cast(value, anno)
                 var = impl.expr_init(var)
@@ -125,9 +123,7 @@ def build_assign_annotated(ctx, target, value, is_static_assign, annotation):
             else:
                 var = build_stmt(ctx, target)
                 if var.ptr.get_rvalue_type() != anno:
-                    raise TaichiSyntaxError(
-                        "Static assign cannot have type overloading"
-                    )
+                    raise TaichiSyntaxError("Static assign cannot have type overloading")
                 var._assign(value)
         return var