Heap package:ghc-heap

With this module, you can investigate the heap representation of Haskell values, i.e. to investigate sharing and lazy evaluation.
Functions for walking GHC's heap This package provides functions for walking the GHC heap data structures and retrieving information about those data structures.
Convert an unpacked heap object, to a `GenClosure b`. The inputs to this function can be generated from a heap object using unpackClosure#.