devel/hs-strict - The NetBSD Packages Collection

This package provides strict versions of some standard Haskell data
types (pairs, Maybe and Either). It also contains strict IO
operations.

It is common knowledge that lazy datastructures can lead to
space-leaks. This problem is particularly prominent, when using lazy
datastructures to store the state of a long-running application in
memory. One common solution to this problem is to use seq and its
variants in every piece of code that updates your state. However a
much easier solution is to use fully strict types to store such state
values. By "fully strict types" we mean types for whose values it
holds that, if they are in weak-head normal form, then they are also
in normal form. Intuitively, this means that values of fully strict
types cannot contain unevaluated thunks.