Type-directed programming for programming education

Type-directed programming, where one uses the overall data structure and type signatures to drive programming, is a well known technique in functional programming. In a strongly typed language such as Haskell, type signatures provide valuable information and context to the function we are working with. Often the type signature alone is enough to define the body of a function or at least to understand the overall shape of the problem.

Combining type-directed programming with a live programming lecturing style provides students with more tools to interrogate and define functions in a setting which is generally found difficult. The live programming setting is especially useful for providing guidance and insight on how to solve problems. type-directed programming helps to provide shape and restriction to what students can implement, moving some weight from the lecturer's explanations and onto the types.