# Haskell Learning Path

This note links the Haskell examples in a suggested order from first project structure through intermediate language and application patterns.

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## 1. Suggested Order

1. `05-haskell/`: a small Cabal library, executable, test suite, and dev shell
2. `06-haskell-shellfor/`: a Haskell package set override and a `shellFor`-based dev shell
3. `07-haskell-deps/`: external Haskell libraries through Cabal `build-depends`
4. `08-haskell-adt/`: algebraic data types, records, and pattern matching
5. `09-haskell-newtype/`: `newtype`, smart constructors, and validation
6. `10-haskell-effects/`: `ReaderT`, `Except`, and constrained application logic
7. `11-haskell-typeclasses/`: custom type classes and per-type instances
8. `12-haskell-parser-combinators/`: parser combinators with Megaparsec

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## 2. What to Focus on at Each Step

- `05-haskell/`: how a Cabal package becomes a flake package, app, dev shell, and check
- `06-haskell-shellfor/`: when a Haskell-specific dev shell is more useful than a generic shell
- `07-haskell-deps/`: why Cabal stays the source of truth for package dependencies
- `08-haskell-adt/`: how to model a problem with constructors before writing behavior
- `09-haskell-newtype/`: how to move validation to the boundary and protect the domain model
- `10-haskell-effects/`: how to separate configuration, logic, and failures
- `11-haskell-typeclasses/`: how to abstract shared behavior across several types
- `12-haskell-parser-combinators/`: how to build a small language from reusable parser pieces

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## 3. Related Notes

- `notes/007-haskell.md`
- `notes/008-haskell-shellfor.md`
- `notes/009-haskell-dependencies.md`
- `notes/010-haskell-adts.md`
- `notes/011-haskell-newtypes.md`
- `notes/012-haskell-effects.md`
- `notes/013-haskell-typeclasses.md`
- `notes/015-haskell-parser-combinators.md`