Haskell

General Documentation:

• The Haskell.org Documentation page links to many things.
• Haskell 2010 Language Report also available in PDF and branch h2010 of https://github.com/haskell/haskell-report.
• GHC User Guide.
• The Typeclassopedia.
• API searches with Hoogle and Hayoo!.

SEDoc documentation pages:

• Modules, Imports and Exports.
• Haskell Stack.
• Haddock.

Other handy stuff:

• Pronounceable names for common Haskell operators

Language

Expressions evaluate to a value that has a (static) type. Values and types are not mixed. Errors are semantically equivalant to ⊥ (bottom), and technically indistinguishable from non-termination, though GHC provides exceptions for this.

Namespaces:

• Values: variables (lc) and value constructors (uc).
• Types: type variables (lc), type constructors (uc) and type classes (uc).
• Module names.

An identifier cannot name both a type constructor and type class in the same scope.