diff --git a/src/interpreter.cc b/src/interpreter.cc
index e1308c1..446b60d 100644
--- a/src/interpreter.cc
+++ b/src/interpreter.cc
@@ -541,11 +541,12 @@ error:
 			assert(!args.empty(), "rotate requires offset"); // TODO(assert)
 			auto offset = std::move(args.front()).n.as_int();
 			auto array = Try(into_flat_array(i, std::span(args).subspan(1)));
-			offset = offset % array.elements.size();
 			if (offset > 0) {
+				offset = offset % array.elements.size();
 				std::rotate(array.elements.begin(), array.elements.begin() + offset, array.elements.end());
 			} else if (offset < 0) {
-				std::rotate(array.elements.rbegin(), array.elements.rbegin() + (-offset), array.elements.rend());
+				offset = -offset % array.elements.size();
+				std::rotate(array.elements.rbegin(), array.elements.rbegin() + offset, array.elements.rend());
 			}
 			return Value::from(std::move(array));
 		});
diff --git a/src/tests/interpreter.cc b/src/tests/interpreter.cc
index 09c169e..fdfb32a 100644
--- a/src/tests/interpreter.cc
+++ b/src/tests/interpreter.cc
@@ -45,6 +45,7 @@ suite intepreter_test = [] {
 			evaluates_to(Value::from(true),       "true");
 			evaluates_to(Value::from(Number(10)), "10");
 			evaluates_to(Value{},                 "nil");
+			evaluates_to(Value::from("foo"),      "'foo");
 		};
 
 		should("evaluate arithmetic") = [] {
@@ -128,6 +129,10 @@ suite intepreter_test = [] {
 			evaluates_to(Value::from(Number(42)), "var x = [i|i] 42; x");
 		};
 
+		should("allow modifying declared variable") = [] {
+			evaluates_to(Value::from(Number(43)), "var x = 42; x = 43; 10; x");
+		};
+
 		should("support array programming") = [] {
 			evaluates_to(Value::from(Array { .elements = {{
 				Value::from(Number(2)),
@@ -275,5 +280,137 @@ suite intepreter_test = [] {
 					quit = true;
 			};
 		};
+
+		should("Update value of array with 'update'") = [] {
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)), Value::from(Number(10)), Value::from(Number(3))
+			}}), "update [1;2;3] 1 10");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)), Value::from(Number(10)), Value::from(Number(3))
+			}}), "update (flat 1 2 3) 1 10");
+		};
+
+		should("Support 'reverse' operation") = [] {
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)), Value::from(Number(2)), Value::from(Number(3))
+			}}), "reverse 3 2 1");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)), Value::from(Number(2)), Value::from(Number(3))
+			}}), "reverse (flat 3 2) 1");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)), Value::from(Number(2)), Value::from(Number(3))
+			}}), "reverse [3;2] 1");
+		};
+
+		should("Support 'min' operation") = [] {
+			evaluates_to(Value::from(Number(10)), "min 10 20");
+			evaluates_to(Value::from(Number(10)), "min 20 10");
+			evaluates_to(Value::from(Chord { .notes = { Note { .base = 0 } } }), "min c d");
+			evaluates_to(Value::from(Chord { .notes = { Note { .base = 0 } } }), "min d c");
+		};
+
+		should("Support 'max' operation") = [] {
+			evaluates_to(Value::from(Number(20)), "max 10 20");
+			evaluates_to(Value::from(Number(20)), "max 20 10");
+			evaluates_to(Value::from(Chord { .notes = { Note { .base = 2 } } }), "max c d");
+			evaluates_to(Value::from(Chord { .notes = { Note { .base = 2 } } }), "max d c");
+		};
+
+		should("Support 'rotate' operation") = [] {
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)),
+				Value::from(Number(2)),
+				Value::from(Number(3)),
+				Value::from(Number(4)),
+				Value::from(Number(5)),
+			}}), "rotate 0 [1;2;3;4;5]");
+
+			should("Support 'rotate' to right via negative rotation index") = [] {
+				evaluates_to(Value::from(Array { .elements = {
+					Value::from(Number(5)),
+					Value::from(Number(1)),
+					Value::from(Number(2)),
+					Value::from(Number(3)),
+					Value::from(Number(4)),
+				}}), "rotate (0-1) [1;2;3;4;5]");
+
+				evaluates_to(Value::from(Array { .elements = {
+					Value::from(Number(4)),
+					Value::from(Number(5)),
+					Value::from(Number(1)),
+					Value::from(Number(2)),
+					Value::from(Number(3)),
+				}}), "rotate (0-2) [1;2;3;4;5]");
+
+				evaluates_to(Value::from(Array { .elements = {
+					Value::from(Number(3)),
+					Value::from(Number(4)),
+					Value::from(Number(5)),
+					Value::from(Number(1)),
+					Value::from(Number(2)),
+				}}), "rotate (0-3) [1;2;3;4;5]");
+
+				evaluates_to(Value::from(Array { .elements = {
+					Value::from(Number(2)),
+					Value::from(Number(3)),
+					Value::from(Number(4)),
+					Value::from(Number(5)),
+					Value::from(Number(1)),
+				}}), "rotate (0-4) [1;2;3;4;5]");
+
+				evaluates_to(Value::from(Array { .elements = {
+					Value::from(Number(1)),
+					Value::from(Number(2)),
+					Value::from(Number(3)),
+					Value::from(Number(4)),
+					Value::from(Number(5)),
+				}}), "rotate (0-5) [1;2;3;4;5]");
+			};
+		};
+
+		should("Support 'rotate' to left via positive rotation index") = [] {
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(2)),
+				Value::from(Number(3)),
+				Value::from(Number(4)),
+				Value::from(Number(5)),
+				Value::from(Number(1)),
+			}}), "rotate 1 [1;2;3;4;5]");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(3)),
+				Value::from(Number(4)),
+				Value::from(Number(5)),
+				Value::from(Number(1)),
+				Value::from(Number(2)),
+			}}), "rotate 2 [1;2;3;4;5]");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(4)),
+				Value::from(Number(5)),
+				Value::from(Number(1)),
+				Value::from(Number(2)),
+				Value::from(Number(3)),
+			}}), "rotate 3 [1;2;3;4;5]");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(5)),
+				Value::from(Number(1)),
+				Value::from(Number(2)),
+				Value::from(Number(3)),
+				Value::from(Number(4)),
+			}}), "rotate 4 [1;2;3;4;5]");
+
+			evaluates_to(Value::from(Array { .elements = {
+				Value::from(Number(1)),
+				Value::from(Number(2)),
+				Value::from(Number(3)),
+				Value::from(Number(4)),
+				Value::from(Number(5)),
+			}}), "rotate 5 [1;2;3;4;5]");
+		};
 	};
 };