Minor fixups in docs plus some minor Refactoring

docs/implementation/bridoc-design.md

@@ -64,13 +64,13 @@ See [this example ast output](output-example-01.md)
             , docLit $ Text.pack " "
             , docForceSingleline typeDoc2
             ]
-        , docPar                                       -- an multi-line result, with the "child" indented.
+          , docPar                                       -- a multi-line result, with the "child" indented.
               typeDoc1                                   -- "Maybe\
               (docEnsureIndent BrIndentRegular typeDoc2) --    Int"
           ]
     ~~~~
 
-  here, all functions prefixed with "doc" produces new BriDoc(F) nodes.
+    here, all functions prefixed with "doc" produce new BriDoc(F) nodes.
     I think this example can be understood already, even when many details
     (what is `docSharedWrapper`?
     What are the exact semantics of the different `doc..` functions?
@@ -144,8 +144,8 @@ in a single line now.
 
 We will not go into detail about how this "alt-transformation" (the one doing
 the "selection work" works and what other transformations follow here.
-For this example not much happens; you can see so in the output which you
+For this example not much happens; you can see so in the final `BriDoc` which
-probably already noticed in the last example.
+you probably already noticed in the last example.
 
 But for the "alt-transformation" itself, lets at least consider what it does:
 We traverse the input BriDoc and whenever a `BDAlt` is encountered, one of the
@@ -215,7 +215,7 @@ We don't use this directly, but the code below uses this,
 and if the type `ToBriDocM` scared you, see how mundane it
 is used here (`m` will be `ToBriDocM` mostly):
 
-~~~~
+~~~~.hs
 allocNodeIndex :: MonadMultiState NodeAllocIndex m => m Int
 allocNodeIndex = do
   NodeAllocIndex i <- mGet

src/Language/Haskell/Brittany.hs

@@ -188,7 +188,8 @@ ppModule lmod@(L loc m@(HsModule _name _exports _imports decls _ _)) = do
         in  (anns', post)
   MultiRWSS.withMultiReader anns' $ processDefault emptyModule
   decls `forM_` ppDecl
-  let finalComments = filter ( fst .> \case
+  let finalComments = filter
+        ( fst .> \case
           ExactPrint.Types.AnnComment{} -> True
           _                             -> False
         )
@@ -257,39 +258,34 @@ layoutBriDoc :: Data.Data.Data ast => ast -> BriDocNumbered -> PPM ()
 layoutBriDoc ast briDoc = do
   -- first step: transform the briDoc.
   briDoc'                       <- MultiRWSS.withMultiStateS BDEmpty $ do
+    -- Note that briDoc is BriDocNumbered, but state type is BriDoc.
+    -- That's why the alt-transform looks a bit special here.
     traceIfDumpConf "bridoc raw" _dconf_dump_bridoc_raw
       $ briDocToDoc
       $ unwrapBriDocNumbered
       $ briDoc
     -- bridoc transformation: remove alts
     transformAlts briDoc >>= mSet
-    mGet
+    mGet >>= briDocToDoc .> traceIfDumpConf "bridoc post-alt"
-      >>= traceIfDumpConf "bridoc post-alt" _dconf_dump_bridoc_simpl_alt
+                                            _dconf_dump_bridoc_simpl_alt
-      .   briDocToDoc
     -- bridoc transformation: float stuff in
-    mGet <&> transformSimplifyFloating >>= mSet
+    mGet >>= transformSimplifyFloating .> mSet
-    mGet
+    mGet >>= briDocToDoc .> traceIfDumpConf "bridoc post-floating"
-      >>= traceIfDumpConf "bridoc post-floating"
                                             _dconf_dump_bridoc_simpl_floating
-      .   briDocToDoc
     -- bridoc transformation: par removal
-    mGet <&> transformSimplifyPar >>= mSet
+    mGet >>= transformSimplifyPar .> mSet
-    mGet
+    mGet >>= briDocToDoc .> traceIfDumpConf "bridoc post-par"
-      >>= traceIfDumpConf "bridoc post-par" _dconf_dump_bridoc_simpl_par
+                                            _dconf_dump_bridoc_simpl_par
-      .   briDocToDoc
     -- bridoc transformation: float stuff in
-    mGet <&> transformSimplifyColumns >>= mSet
+    mGet >>= transformSimplifyColumns .> mSet
-    mGet
+    mGet >>= briDocToDoc .> traceIfDumpConf "bridoc post-columns"
-      >>= traceIfDumpConf "bridoc post-columns" _dconf_dump_bridoc_simpl_columns
+                                            _dconf_dump_bridoc_simpl_columns
-      .   briDocToDoc
+    -- bridoc transformation: indent
-    -- -- bridoc transformation: indent
+    mGet >>= transformSimplifyIndent .> mSet
-    mGet <&> transformSimplifyIndent >>= mSet
+    mGet >>= briDocToDoc .> traceIfDumpConf "bridoc post-indent"
-    mGet
+                                            _dconf_dump_bridoc_simpl_indent
-      >>= traceIfDumpConf "bridoc post-indent" _dconf_dump_bridoc_simpl_indent
+    mGet >>= briDocToDoc .> traceIfDumpConf "bridoc final"
-      .   briDocToDoc
+                                            _dconf_dump_bridoc_final
-    mGet
-      >>= traceIfDumpConf "bridoc final" _dconf_dump_bridoc_final
-      .   briDocToDoc
     -- -- convert to Simple type
     -- simpl <- mGet <&> transformToSimple
     -- return simpl
@@ -317,10 +313,9 @@ layoutBriDoc ast briDoc = do
 
   state' <- MultiRWSS.withMultiStateS state $ layoutBriDocM briDoc'
 
-  let
+  let remainingComments =
-    remainingComments =
         extractAllComments =<< Map.elems (_lstate_comments state')
   remainingComments
-    `forM_` (mTell . (:[]) . LayoutErrorUnusedComment . show . fst)
+    `forM_` (fst .> show .> LayoutErrorUnusedComment .> (:[]) .> mTell)
 
   return $ ()