id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
5290,Add UNPACK support to Template Haskell,mikhail.vorozhtsov,,"I've just hacked it in:
{{{
$ ghci -XTemplateHaskell
GHCi, version 7.1.20110630: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
λ> import Language.Haskell.TH
λ> runQ [d| data T = T {-# UNPACK #-} !Int |]
Loading package array-0.3.0.2 ... linking ... done.
Loading package containers-0.4.0.0 ... linking ... done.
Loading package pretty-1.0.2.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
[DataD [] T [] [NormalC T [(Unpacked,ConT GHC.Types.Int)]] []]
λ>
}}}
TH.hs:
{{{
{-# LANGUAGE TemplateHaskell #-}

module TH where

import Language.Haskell.TH

d :: Q [Dec]
d = return [DataD [] n [] [NormalC n [(Unpacked,ConT ''Int)]] []]
  where n = mkName ""T"" 
}}}
Main.hs:
{{{
{-# LANGUAGE TemplateHaskell #-}

import TH

$(d)

instance Show T where
  show (T i) = show i

main = putStrLn $ show (T 10)
}}}
Compiling and running:
{{{
$ ghc -ddump-splices -fforce-recomp Main.hs
[1 of 2] Compiling TH               ( TH.hs, TH.o )
[2 of 2] Compiling Main             ( Main.hs, Main.o )
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Loading package pretty-1.0.2.0 ... linking ... done.
Loading package array-0.3.0.2 ... linking ... done.
Loading package containers-0.4.0.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
Main.hs:1:1: Splicing declarations
    d
  ======>
    Main.hs:5:3
    data T = T {-# UNPACK #-} !Int
Linking Main ...
$ ./Main
10
}}}
Please consider merging.",feature request,closed,high,7.4.1,Template Haskell,7.1,fixed,,,Unknown/Multiple,Unknown/Multiple,None/Unknown,,th/T5290,,,