mgsloan

#!/bin/sh -e

# Script I wrote before I realized
# https://github.com/MatthieuBizien/roam-to-git exists

if [ "$#" -eq 1 ]; then
    LAST_ROAM_EXPORT=$1
elif [ "$#" -eq 0 ]; then
    echo "Attempting to use XDG info to find roam export."
    # Load XDG dir configuration into variables

mgsloan

ErrorMonoidMaybeInt.hs:12:3-48: Splicing declarations
    explainInstanceError [t| Monoid (Maybe Int) |]
  ======>
    main_a6aM
      = putStrLn
          (displayInst
             (resolveMonoid (Data.Proxy.Proxy :: Data.Proxy.Proxy (Maybe Int))))
    class Semigroup_ a_a4Ra => Monoid_ (a_a4Ra :: GHC.Types.Type) where
      resolveMonoid :: Data.Proxy.Proxy a_a4Ra -> Inst
    instance OVERLAPPABLE #-} base-4.12.0.0:Data.Typeable.Internal.Typeable a_a4Ra =>

mgsloan

-- Context: https://github.com/ghc-proposals/ghc-proposals/pull/273#issuecomment-530215302

{-# LANGUAGE ExistentialQuantification #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE UndecidableInstances #-}

import Data.Typeable

mgsloan

Context: ghc-proposals/ghc-proposals#273 (comment)

I have not reviewed this proposal thoroughly, however I would really like this feature and have considered proposing it in the past. To make this more clearly defined and understandable for users, I'd like to propose a simple rule for what is allowed:

Local types could desugar to top level declarations

My intuition says that if this holds true then the feature becomes much easier to implement than if it does not. As far as I can tell this rule is mostly already followed in the proposal. Specifically:

All instances remain (conceptually) global, but they may involve local types and values

mgsloan

diff --git a/src/RIO.hs b/src/RIO.hs
index e4e2c66..e071714 100644
--- a/src/RIO.hs
+++ b/src/RIO.hs
@@ -1,3 +1,4 @@
+-- | This mo
 module RIO
   ( module RIO.Prelude.Display
   , module RIO.Prelude.Extra
diff --git a/src/RIO/Prelude/Reexports.hs b/src/RIO/Prelude/Reexports.hs

mgsloan

Keybase proof

I hereby claim:

• I am mgsloan on github.
• I am mgsloan (https://keybase.io/mgsloan) on keybase.
• I have a public key ASD0wSGDjAfr3397iicKObFGTTGmQyUVookmyd7W7GdH-go

To claim this, I am signing this object:

mgsloan

All public gists which do not specify a different license, listed at https://gist.github.com/mgsloan, are covered by the MIT License, http://www.opensource.org/licenses/mit-license.php

Copyright 2017 Michael Sloan

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT H

mgsloan

#!/bin/sh

# Copyright 2017 Michael Sloan
# This file is MIT licensed.

changed="$(git diff --name-only --cached)"
changed_and_ignored="$(echo "$changed" | git check-ignore --stdin --no-index | tr -d '[:space:]')"

if test -z "$changed_and_ignored" ;
then

mgsloan

fn main() {
    let mut x = 1;
    wat(|i| { x += i; return x; });
    println!("{}", x);
}

fn wat<F>(f: F) -> u32 where F: FnMut(u32) -> u32 {
    foo(f)
}

mgsloan

mgsloan@computer:~/fpco/stack$ git checkout v0.1.0.0
...

mgsloan@computer:~/fpco/stack$ stack build
...
Installing executable(s) in
/home/mgsloan/fpco/stack/.stack-work/install/x86_64-linux/lts-2.9/7.8.4/bin
Registering stack-0.1.0.0...
Completed 123 action(s).