add basic support for tuples

core/vm.go

@@ -132,6 +132,10 @@ const (
 	// InstructionConcatLists concatenate lists, producing a new list with the values of both lists. Pops two lists.
 	InstructionConcatLists
 
+	// InstructionFormTuple pop n+1 (u16) items from the stack, and create a new tuple with the items. The top value
+	// on the stack is the last value in the tuple.
+	InstructionFormTuple
+
 	// InstructionBreakpoint for debugging purposes
 	InstructionBreakpoint
 )
@@ -992,6 +996,18 @@ func (vm *VM) Next() bool {
 			append(l.Items, r.Items...),
 		})
 
+	case InstructionFormTuple:
+		n := int(vm.NextU16())
+
+		items := make([]Value, n)
+		for i := n - 1; i >= 0; i-- {
+			items[i] = vm.Stack.Pop()
+		}
+
+		vm.Stack.Push(&TupleValue{
+			items,
+		})
+
 	case InstructionDescend:
 		vm.descend()