Enable .slice method for LazyExprs

Author: Luke Shaw

tests/ndarray/test_lazyexpr.py

@@ -1066,8 +1066,8 @@ def test_eval_item(array_fixture):
     np.testing.assert_allclose(res[()], nres[0:10:2])
 
 
-# Test stringeval with a slice
-def test_stringeval_slice(array_fixture):
+# Test lazyexpr's slice method
+def test_eval_slice(array_fixture):
     a1, a2, a3, a4, na1, na2, na3, na4 = array_fixture
     expr = blosc2.lazyexpr("a1 + a2 - (a3 * a4)", operands={"a1": a1, "a2": a2, "a3": a3, "a4": a4})
     nres = ne_evaluate("na1 + na2 - (na3 * na4)")[:2]
@@ -1078,6 +1078,7 @@ def test_stringeval_slice(array_fixture):
     assert isinstance(res, np.ndarray)
     np.testing.assert_allclose(res, nres)
 
+    # string lazy expressions automatically use .slice internally
     expr1 = blosc2.lazyexpr("a1 * a2", operands={"a1": a1, "a2": a2})
     expr2 = blosc2.lazyexpr("expr1[:2] + a3[:2]")
     nres = ne_evaluate("(na1 * na2) + na3")[:2]