nix-playgraound/37-haskell-transformer-stack/README.md

37-haskell-transformer-stack

This example shows intermediate Haskell effect composition with a transformer stack.

It includes:

• a rollout environment carried by ReaderT,
• explicit rollout failures carried by ExceptT,
• ordered audit lines carried by Writer,
• one stacked workflow that validates and renders a rollout summary, and
• a test suite run by nix flake check.

Useful commands:

nix develop
cabal run
cabal run -- api:production:4
cabal test

nix build
./result/bin/mini-stack api:production:4

nix run . -- api:production:4
nix flake check