# An example that defines and uses stacks of integers.
# The implementation is done with a simple linked list.
# It features: free constructors, nullable types and some adaptive typing.
-module int_stack
+module int_stack is example
# A stack of integer implemented by a simple linked list.
# Note that this is only a toy class since a real linked list will gain to use
-# generics and extends interfaces, like Collection, from the standard library.
+# generics and extends interfaces, like `Collection`, from the `core` library.
class IntStack
# The head node of the list.
# Null means that the stack is empty.