0.8

Version 0.8

Thanks to Adam Wespiser, Cullin Poreski, Scott Fleischman
and William Yao for lots of contributions.

Materialized CTEs

Scott Fleischman contributed materialization support to Squeal's
WITH statements.

LTrees and UUID

New packages squeal-postgresql-ltree and squeal-postgresql-uuid-ossp
were created to offer functionality from those Postgres extensions.

Safe Transactions

Previously, Squeal transactions were "unsafe", allowing for arbitrary
IO. Now, Squeal provides a new type Transaction that is a RankNType.

type Transaction db x = forall m.
  ( MonadPQ db m
  , MonadResult m
  , MonadCatch m
  ) => m x

A Transaction only permits database operations and error handling,
no arbitrary IO. The class MonadResult is new but all of its
methods are old and used to be constrained as MonadIO,
now as MonadResult.

Additionally, a new function withSavepoint was added, allowing
for a kind of nested transactions.