types) and just one field (which are technically not a product).
\stopdesc
\startdesc{Enumerated types}
+ \defref{enumerated types}
An enumerated type is an algebraic datatype with multiple constructors, but
none of them have fields. This is essentially a way to get an
enum-like type containing alternatives.
variables are used by a function can be completely determined from its
type signature (as opposed to the stream approach, where a function
looks the same from the outside, regardless of what state variables it
- uses (or whether it's stateful at all).
+ uses or whether it's stateful at all).
This approach is the one chosen for Cλash and will be examined more
closely below.
has to somehow know the current state for these called functions. The
only way to do this, is to put these \emph{substates} inside the
caller's state. This means that a function's state is the sum of the
- states of all functions it calls, and its own state.
+ states of all functions it calls, and its own state. This sum
+ can be obtained using something simple like a tuple, or possibly
+ custom algebraic types for clarity.
This also means that the type of a function (at least the "state"
part) is dependent on its own implementation and of the functions it
\todo{Sidenote: One or more state arguments?}
- \subsection{Explicit state annotation}
+ \subsection[sec:description:stateann]{Explicit state annotation}
To make our stateful descriptions unambigious and easier to translate,
we need some way for the developer to describe which arguments and
results are intended to become stateful.