Output of data/newtype puts newlines after the "data" but before the head.

[solidsnack]

One ends up with output like:

data











     Maybe t = Just t | Nothing

[solidsnack]

I can not attach files so here you go:

.5.1/src/Language/Haskell/Exts/Annotated/ExactPrint.hs

@@ -448 +448 @@
     AssocRight l -> printString "infixr"
 
 instance ExactP DataOrNew where
-  exactP (DataType l) = printString "data"
-  exactP (NewType  l) = printString "newtype"
+  exactP dn =
+      let a = (srcInfoSpan . ann) dn
+          tag = case dn of { DataType _ -> "data" ; NewType _ -> "newtype" }
+       in printStringAt (pos a) tag
 
 instance ExactP Decl where
   exactP decl = case decl of

[solidsnack]

Replying to solidsnack:

I can not attach files so here you go:

Recovering the diff from this Trac markup processor is pretty hard.

Wed Dec 30 10:48:26 PST 2009  Jason Dusek <jason.dusek@gmail.com>
  * Clarity/uniformity.
Wed Dec 30 10:20:25 PST 2009  Jason Dusek <jason.dusek@gmail.com>
  * Would work if we actually parsed a location.
diff -rN -u old-haskell-src-exts-1.5.1/src/Language/Haskell/Exts/Annotated/ExactPrint.hs new-haskell-src-exts-1.5.1/src/Language/Haskell/Exts/Annotated/ExactPrint.hs
--- old-haskell-src-exts-1.5.1/src/Language/Haskell/Exts/Annotated/ExactPrint.hs	2009-12-30 11:16:40.000000000 -0800
+++ new-haskell-src-exts-1.5.1/src/Language/Haskell/Exts/Annotated/ExactPrint.hs	2009-12-30 11:16:40.000000000 -0800
@@ -448,8 +448,10 @@
     AssocRight l -> printString "infixr"
 
 instance ExactP DataOrNew where
-  exactP (DataType l) = printString "data"
-  exactP (NewType  l) = printString "newtype"
+  exactP dn =
+      let a = (srcInfoSpan . ann) dn
+          tag = case dn of { DataType _ -> "data" ; NewType _ -> "newtype" }
+       in printStringAt (pos a) tag
 
 instance ExactP Decl where
   exactP decl = case decl of

[nibro]

The bug is real but the fix is not. The problem is that exactPrint always prints the first token at (0,0) regardless of where it should really be printed. The fix is that exactPrint should call exactPC, not exactP. Fixed in 1.5.2, case closed.