Nathan Howell NathanHowell

## better-compile-errors.hs
instance (a ~ Proxy "Sum types are not supported by LLVM") => GGetElementIndex a (x :+: y) where
  type GGetElementPtrType a (x :+: y) = Void
  ggetElementIndex _ _ = error "Sum types are not supported by LLVM"

type family StructElement (a :: [*]) (n :: Nat) :: * where
  StructElement (x ': xs) 0 = x
  StructElement (x ': xs) n = StructElement xs (n - 1)
  StructElement '[] n = Proxy "Attempting to index past end of structure"

## 1.idr
module Data.Fin

%default total
%access public export

||| Numbers strictly less than some bound.  The name comes from "finite sets".
|||
||| It's probably not a good idea to use `Fin` for arithmetic, and they will be
||| exceedingly inefficient at run time.
||| @ n the upper bound

## error.txt
[1 of 1] Compiling Repro            ( repro.hs, interpreted )

repro.hs:24:13:
    Cannot instantiate unification variable ‛b0’
    with a type involving foralls:
      (forall r. (a1 -> IO r) -> IO r) -> DecodeAST a1
      Perhaps you want ImpredicativeTypes
    In the expression:
        GHC.Prim.coerce
          (anyContToM ::

## gist:6880968
{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}

import Data.Typeable

convert :: (Typeable t, Typeable b) => (forall a . Typeable a => a -> r) -> [t] -> b -> r
convert f (x:xs) b = convert f xs (x, b)
convert f    []  b = f b

## .gitignore
.cabal-sandbox/
dist/
cabal.config
cabal.sandbox.config

.*.swp

## barf.txt
gdb ./a.out
GNU gdb 6.3.50-20050815 (Apple version gdb-1820) (Sat Jun 16 02:40:11 UTC 2012)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared libraries .. done

(gdb) run

## A.cmm
#include <Cmm.h>

getInfoTable (P_ a)
{
  W_ clos, info, type;
  clos = UNTAG(a);
  info = %GET_STD_INFO(clos);
  return (info);
}

## thread-fixio.hs
import Control.Concurrent
import System.IO

t :: ThreadId -> IO ()
t tid = print ("mah thread", tid)

main :: IO ()
main = do
  _tid <- fixIO (forkIO . t)
  threadDelay 100000000

## cn.hs
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeSynonymInstances #-}
{-# LANGUAGE TypeOperators #-}

import Data.Proxy
import GHC.Generics

## gist:5557902
{-# LANGUAGE FlexibleContexts #-}

import Control.Monad.Base
import Control.Monad.Trans.Control
import Control.Concurrent.MSem as MSem

withMSem :: (MonadBaseControl IO m, Integral i) => MSem i -> m a -> m a
withMSem = liftBaseOp_ . MSem.with