Comments, and improvement to pretty-printing of HsGroup

diff --git a/compiler/hsSyn/HsBinds.lhs b/compiler/hsSyn/HsBinds.lhs
index c4d38fd..5709e58 100644 (file)
--- a/compiler/hsSyn/HsBinds.lhs
+++ b/compiler/hsSyn/HsBinds.lhs
@@ -66,11 +66,11 @@ data HsLocalBindsLR idL idR -- Bindings in a 'let' expression
 type HsValBinds id = HsValBindsLR id id
 
 data HsValBindsLR idL idR  -- Value bindings (not implicit parameters)
-  = ValBindsIn             -- Before typechecking
+  = ValBindsIn             -- Before renaming
        (LHsBindsLR idL idR) [LSig idR] -- Not dependency analysed
                                        -- Recursive by default
 
-  | ValBindsOut                       -- After renaming
+  | ValBindsOut                   -- After renaming
        [(RecFlag, LHsBinds idL)]       -- Dependency analysed, later bindings 
                                         -- in the list may depend on earlier
                                         -- ones.

diff --git a/compiler/hsSyn/HsDecls.lhs b/compiler/hsSyn/HsDecls.lhs
index dc4bac7..dff8ce7 100644 (file)
--- a/compiler/hsSyn/HsDecls.lhs
+++ b/compiler/hsSyn/HsDecls.lhs
@@ -221,16 +221,25 @@ instance OutputableBndr name => Outputable (HsGroup name) where
                   hs_fords  = foreign_decls,
                   hs_defds  = default_decls,
                   hs_ruleds = rule_decls })
-       = vcat [ppr_ds fix_decls, ppr_ds default_decls, 
-               ppr_ds deprec_decls, ppr_ds ann_decls,
-               ppr_ds rule_decls,
-               ppr val_decls,
-               ppr_ds tycl_decls, ppr_ds inst_decls,
-                ppr_ds deriv_decls,
-               ppr_ds foreign_decls]
+       = vcat_mb empty 
+            [ppr_ds fix_decls, ppr_ds default_decls, 
+            ppr_ds deprec_decls, ppr_ds ann_decls,
+            ppr_ds rule_decls,
+            if isEmptyValBinds val_decls 
+                then Nothing 
+                else Just (ppr val_decls),
+            ppr_ds tycl_decls, ppr_ds inst_decls,
+             ppr_ds deriv_decls,
+            ppr_ds foreign_decls]
        where
-         ppr_ds [] = empty
-         ppr_ds ds = blankLine $$ vcat (map ppr ds)
+         ppr_ds [] = Nothing
+         ppr_ds ds = Just (vcat (map ppr ds))
+
+          vcat_mb :: SDoc -> [Maybe SDoc] -> SDoc
+         -- Concatenate vertically with white-space between non-blanks
+          vcat_mb _    []             = empty
+          vcat_mb gap (Nothing : ds) = vcat_mb gap ds
+          vcat_mb gap (Just d  : ds) = gap $$ d $$ vcat_mb blankLine ds
 
 data SpliceDecl id 
   = SpliceDecl                 -- Top level splice