Switch to a peek-driven version of value
Switch to a peek-driven version of value

This drops use of the (<|>) combinator, and greatly reduces the
extent to which we allocate unused thunks. As a result, it improves
both runtime and heap usage significantly.

--HG--
extra : rebase_source : 62bc8759400db5a2bc644f5da3fe19c0d10d5d96

lpsmith/aeson,timmytofu/aeson