Speakers: Ganesh Sittampalam and Oliver Charles.
Writing a Type-Safe Heterogenous Map.
Speaker: Ganesh Sittampalam.
Ganesh recently found himself in need of a variant of Data.Map which could contain values of different types and retrieve them with a type-safe API. Find nothing appropriate on Hackage he spent a little while knocking up his own wrapper using Typeable. Includes a basic use of GADTs and Type Families.
Batched Queries and Applicative Functors.
Speaker: Oliver Charles.
Accessing databases is a task we have to do often, yet it still requires care to be done efficiently. A big problem is the "n+1" selects problem, where one queries the database inside loops, which has a terrible performance profile. However, such code is arguably more declarative and easier to reason about. In this talk, Oliver will show us a solution to the problem using a new "Querying" applicative functor, and then use some of Haskell's more advanced feature to allow this functor to run multiple different types of queries within the same loop.