Haskell for Mac now displays local type information in the module editor, when using ⌘I (or three finger tap, if enabled).

You can now query the type of any proper subexpression in a function definition, including the types of local variable and function definitions. Even if there are type errors, partial type information is provided. This significantly simplifies understanding and writing code.

Moreover, documentation links in info popovers now work for LTS packages that are not bundled with Haskell for Mac. They will take you to the relevant documentation page on Stackage .

GHC 8 and LTS Haskell 8.9

Haskell for Mac is now based on GHC 8.0.2 and the package set of LTS Haskell 8.9. This provides access to wide range of new language features, including the following:

  1. TypeInType: kinds support the full range of type features, including explicit quantification over kind variables, higher-rank kinds, and the use of type synonyms and families in kinds.

  2. Injective type families: type families that can be annotated with injectivity information.

  3. Applicative do notation: an alternative translation of the do notation using Applicative, instead of Monad operations, where possible.

  4. Duplicate record fields: provides support for record types with identically-named fields.

Let-less playgrounds

The let keyword in toplevel variable and function definitions in playgrounds can now be omitted (so that these definitions look like those in Haskell modules).

A new theme

Simon Holywell contributed the new Paraíso Dark editor theme.