Update library to latest compiler(s)

Built with GHC 8.2.2, 8.4.4, 8.6.5

.travis.yml

@@ -1,27 +1,20 @@
-language: c
+language: haskell
 
 sudo: false
 
+git:
+  depth: 5
+
+cache:
+  directories:
+    - "$HOME/.cabal/store"
+
 matrix:
   include:
-    - env: CABALVER=1.16 GHCVER=7.6.3
-      addons: {apt: {packages: [cabal-install-1.16,ghc-7.6.3], sources: [hvr-ghc]}}
-    - env: CABALVER=1.18 GHCVER=7.8.4
-      addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4], sources: [hvr-ghc]}}
-    - env: CABALVER=1.22 GHCVER=7.10.3 RUN_TESTS=--run-tests
-      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.3],sources: [hvr-ghc]}}
-    - env: CABALVER=1.24 GHCVER=8.0.1 RUN_TESTS=--run-tests
-      addons: {apt: {packages: [cabal-install-1.24,ghc-8.0.1],sources: [hvr-ghc]}}
-    - env: CABALVER=head GHCVER=head RUN_TESTS=--run-tests
-      addons: {apt: {packages: [cabal-install-head,ghc-head],  sources: [hvr-ghc]}}
-
-  allow_failures:
-    - env: CABALVER=1.16 GHCVER=7.6.3 # weird spec problems
-    - env: CABALVER=1.18 GHCVER=7.8.4 # weird spec problems
-    - env: CABALVER=head GHCVER=head RUN_TESTS=--run-tests
-
-before_install:
-  - export PATH=$HOME/.cabal/bin:/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
+    - ghc: 8.0.1
+    - ghc: 8.2.2
+    - ghc: 8.4.4
+    - ghc: 8.6.5
 
 install:
   - cabal update

ldap-client.cabal

@@ -13,10 +13,10 @@ category:            Network
 build-type:          Simple
 cabal-version:       >= 1.10
 tested-with:
-    GHC == 7.6.3
-  , GHC == 7.8.4
-  , GHC == 7.10.1
-  , GHC == 8.0.1
+    GHC == 8.0.1
+  , GHC == 8.2.2
+  , GHC == 8.4.4
+  , GHC == 8.6.5
 extra-source-files:
   README.markdown
   CHANGELOG.markdown
@@ -57,6 +57,7 @@ library
     , bytestring
     , connection    >= 0.2
     , containers
+    , fail
     , network       >= 2.6
     , semigroups    >= 0.16
     , stm

src/Ldap/Asn1/FromAsn1.hs

@@ -11,6 +11,9 @@ import           Control.Applicative (Alternative(..), liftA2, optional)
 import           Control.Applicative (Applicative(..), Alternative(..), liftA2, optional)
 #endif
 import           Control.Monad (MonadPlus(..), (>=>), guard)
+#if __GLASGOW_HASKELL__ >= 86
+import           Control.Monad.Fail (MonadFail, fail)
+#endif
 import           Data.ASN1.Types (ASN1)
 import qualified Data.ASN1.Types as Asn1
 import           Data.Foldable (asum)
@@ -416,6 +419,11 @@ instance MonadPlus (Parser s) where
   Parser ma `mplus` Parser mb =
     Parser (\s -> ma s `mplus` mb s)
 
+#if __GLASGOW_HASKELL__ >= 86
+instance MonadFail (Parser s) where
+  fail _ = mzero
+#endif
+
 parse :: Parser s a -> s -> Maybe (s, a)
 parse = unParser
 

src/Ldap/Client/Internal.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE NamedFieldPuns #-}
 module Ldap.Client.Internal
@@ -35,7 +36,11 @@ import           Data.ByteString (ByteString)
 import           Data.List.NonEmpty (NonEmpty)
 import           Data.Text (Text)
 import           Data.Typeable (Typeable)
+#if __GLASGOW_HASKELL__ >= 84
+import           Network.Socket (PortNumber)
+#else
 import           Network (PortNumber)
+#endif
 import           Network.Connection (TLSSettings)
 
 import qualified Ldap.Asn1.Type as Type