How can I automatically derive Typeable instance for DataKinds derived types?
haskell,types,deriving,data-kinds
Yes, you can use the AutoDeriveTypeable extension. For the other part, the closest thing I could think of was to put Typeable c => inside the GADT definition as follows: {-# LANGUAGE AutoDeriveTypeable #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE DataKinds #-} import Data.Typeable import qualified Data.Map as M type...
Custom deriving(Read,Show) for enum type
haskell,template-haskell,deriving
The paper Invertible Syntax Descriptions: Unifying Parsing and Pretty Printing describes one particularly idiomatic solution. Your example looks like this, using the invertible-syntax package based on that paper: import Prelude hiding (Applicative(..), print) import Data.Maybe (fromJust) import Text.Syntax import Text.Syntax.Parser.Naive import Text.Syntax.Printer.Naive data TVShow = BobsBurgers | MrRobot | BatmanTAS...
Deriving instance Typeable with context
Might I suggest not doing that. Datatype contexts are bad in pretty much every way possible. There's a reason that they've been deprecated. If you really, really, want them, use GADTs. If you don't use contexts, this is trivial {-# LANGUAGE DeriveDataTypeable #-} import Data.Typeable import Data.Data data ErrorResponse ty...
Deriving Generic from data declared in another file fails
haskell,ghc,deriving,ghc-generics
I'm using GHC 7.8.3 (from the Haskell Platform). Below is a cabal.config file with the specific versions used in the sandbox. constraints: aeson ==0.8.0.2, array ==0.5.0.0, attoparsec ==0.12.1.2, base ==4.7.0.1, bytestring ==0.10.4.0, containers ==0.5.5.1, deepseq ==1.3.0.2, dlist ==0.7.1, generic ==0.1.0.0, generic-aeson ==0.2.0.2, generic-deriving ==1.7.0, ghc-prim ==0.3.1.0, hashable ==1.2.2.0, integer-gmp ==0.5.1.0,...
Are all differentiable types Monads
haskell,monads,zipper,deriving
No. The void functor data V a is differentiable, but return cannot be implemented for it.
How to use deriving and batteries at same time in OCaml?
ocaml,deriving,ocaml-batteries
I've had no problem installing both libraries (batteries 2.1.0 and deriving 0.5) with OCaml 4.00.1 (and Opam 0.9.6) You might want to check this question: opam upgrade wants to downgrade a bunch of packages -- not sure whether this is relevant, but it seems that it might be. Good...
Why does Either derives Show but Maybe does not?
haskell,show,maybe,either,deriving
The instance for Maybe is defined explicitly in GHC.Show, along with instances for a whole bunch of other common types like tuples. You can find out where an instance was defined using the :i command in ghci: Prelude> :i Maybe data Maybe a = Nothing | Just a -- Defined...
Opam install deriving, syntax error
It seems you forgot to provide deriving.syntax package. Use the following _tags file: true: syntax(camlp4o) true: package(deriving,deriving.syntax) true: thread,debug,annot true: bin_annot ...