Fix type application layouting (fixes #48)

- one-line externals are not detected as multiline in backend
- layouting of EAsPat (when TypeApplications is disabled)
- layouting of HsTyLit (TypeApplications with literals)

src-literatetests/tests.blt

@@ -956,6 +956,7 @@ runBrittany tabSize text = do
 foo = bar @Baz
 
 #test comment-before-BDCols
+{-# LANGUAGE TypeApplications #-}
 layoutPatternBindFinal alignmentToken binderDoc mPatDoc clauseDocs = do
   docAlt
     $  -- one-line solution
@@ -1026,6 +1027,21 @@ foo n = case n of
 bar n = case n of
   (-2, -2) -> (-2, -2)
 
+#test issue 48 a
+
+foo =
+  let a    = b@1
+      cccc = ()
+  in  foo
+
+#test issue 48 b
+
+{-# LANGUAGE TypeApplications #-}
+foo =
+  let a    = b @1
+      cccc = ()
+  in  foo
+
 
 ###############################################################################
 ###############################################################################

src/Language/Haskell/Brittany/Internal/Backend.hs

@@ -312,6 +312,7 @@ briDocIsMultiLine briDoc = rec briDoc
     BDForceMultiline  _     -> True
     BDForceSingleline bd    -> rec bd
     BDForwardLineMode bd    -> rec bd
+    BDExternal _ _ _ t | [_] <- Text.lines t -> False
     BDExternal _ _ _ _      -> True
     BDAnnotationPrior _ bd  -> rec bd
     BDAnnotationKW _ _ bd   -> rec bd

src/Language/Haskell/Brittany/Internal/Layouters/Expr.hs

@@ -902,9 +902,11 @@ layoutExpr lexpr@(L _ expr) = docWrapNode lexpr $ case expr of
     briDocByExactInlineOnly "HsTickPragma{}" lexpr
   EWildPat{} -> do
     docLit $ Text.pack "_"
-  EAsPat{} -> do
-    -- TODO
-    briDocByExactInlineOnly "EAsPat{}" lexpr
+  EAsPat asName asExpr -> do
+    docSeq
+      [ docLit $ (lrdrNameToText asName) <> Text.pack "@"
+      , layoutExpr asExpr
+      ]
   EViewPat{} -> do
     -- TODO
     briDocByExactInlineOnly "EViewPat{}" lexpr

src/Language/Haskell/Brittany/Internal/Layouters/Type.hs

@@ -19,6 +19,7 @@ import           Language.Haskell.GHC.ExactPrint.Types ( mkAnnKey )
 import           HsSyn
 import           Name
 import           Outputable ( ftext, showSDocUnsafe )
+import           BasicTypes
 
 import           DataTreePrint
 
@@ -599,8 +600,18 @@ layoutType ltype@(L _ typ) = docWrapNode ltype $ case typ of
       ]
   HsExplicitTupleTy{} -> -- TODO
     briDocByExactInlineOnly "HsExplicitTupleTy{}" ltype
-  HsTyLit{} -> -- TODO
-    briDocByExactInlineOnly "HsTyLit{}" ltype
+  HsTyLit lit -> case lit of
+#if MIN_VERSION_ghc(8,2,0) /* ghc-8.2 */
+    HsNumTy (SourceText srctext) _ -> docLit $ Text.pack srctext
+    HsNumTy NoSourceText _ ->
+      error "overLitValBriDoc: literal with no SourceText"
+    HsStrTy (SourceText srctext) _ -> docLit $ Text.pack srctext
+    HsStrTy NoSourceText _ ->
+      error "overLitValBriDoc: literal with no SourceText"
+#else /* ghc-8.0 */
+    HsNumTy srctext _ -> docLit $ Text.pack srctext
+    HsStrTy srctext _ -> docLit $ Text.pack srctext
+#endif
   HsCoreTy{} -> -- TODO
     briDocByExactInlineOnly "HsCoreTy{}" ltype
   HsWildCardTy _ ->