backport __getitem__ on grid (#28)

* getitem

* Adding getitem

Author: weinbe58

src/bloqade/geometry/dialects/grid/types.py

@@ -1,7 +1,7 @@
 import dataclasses
 from functools import cached_property
 from itertools import chain, product
-from typing import Any, Generic, Sequence, TypeVar
+from typing import Any, Generic, Literal, Sequence, TypeVar, overload
 
 from kirin import ir, types
 from kirin.dialects import ilist
@@ -11,6 +11,26 @@
 NumY = TypeVar("NumY")
 
 
+def get_indices(size: int, index: Any) -> ilist.IList[int, Any]:
+    if isinstance(index, slice):
+        return ilist.IList(range(size)[index])
+    elif isinstance(index, slice):
+        slice_value = index
+        return ilist.IList(range(size)[slice_value])
+    elif isinstance(index, int):
+        if index < 0:
+            index += size
+
+        if index < 0 or index >= size:
+            raise IndexError("Index out of range")
+
+        return ilist.IList([index])
+    elif isinstance(index, ilist.IList):
+        return index
+    else:
+        raise TypeError("Index must be an int, slice, or IList")
+
+
 @dataclasses.dataclass
 class Grid(ir.Data["Grid"], Generic[NumX, NumY]):
     x_spacing: tuple[float, ...]
@@ -198,6 +218,57 @@ def get_view(
         """
         return SubGrid(parent=self, x_indices=x_indices, y_indices=y_indices)
 
+    @overload
+    def __getitem__(
+        self, indices: tuple[int, int]
+    ) -> "Grid[Literal[1], Literal[1]]": ...
+    @overload
+    def __getitem__(
+        self, indices: tuple[int, slice | list[int]]
+    ) -> "Grid[Literal[1], Any]": ...
+
+    @overload
+    def __getitem__(
+        self, indices: tuple[int, ilist.IList[int, Ny]]
+    ) -> "Grid[Literal[1], Ny]": ...
+    @overload
+    def __getitem__(
+        self, indices: tuple[slice | list[int], int]
+    ) -> "Grid[Any, Literal[1]]": ...
+    @overload
+    def __getitem__(
+        self, indices: tuple[slice | list[int], slice]
+    ) -> "Grid[Any, Any]": ...
+
+    @overload
+    def __getitem__(
+        self, indices: tuple[slice | list[int], ilist.IList[int, Ny]]
+    ) -> "Grid[Any, Ny]": ...
+    @overload
+    def __getitem__(
+        self, indices: tuple[ilist.IList[int, Nx], int]
+    ) -> "Grid[Nx, Literal[1]]": ...
+
+    @overload
+    def __getitem__(
+        self, indices: tuple[ilist.IList[int, Nx], slice | list[int]]
+    ) -> "Grid[Nx, Any]": ...
+
+    @overload
+    def __getitem__(
+        self, indices: tuple[ilist.IList[int, Nx], ilist.IList[int, Ny]]
+    ) -> "Grid[Nx, Ny]": ...
+
+    def __getitem__(self, indices):
+        if len(indices) != 2:
+            raise IndexError("Grid indexing requires two indices (x, y)")
+
+        x_index, y_index = indices
+        x_indices = get_indices(len(self.x_spacing) + 1, x_index)
+        y_indices = get_indices(len(self.y_spacing) + 1, y_index)
+
+        return self.get_view(x_indices=x_indices, y_indices=y_indices)
+
     def __hash__(self) -> int:
         return id(self)