fine-grained space merging

Main.hs

@@ -112,13 +112,31 @@ zeal (Conflict m o y) =
     pops ms ys = ((ms, ys), [])
 zeal x = [x]
 
-resolve Config {..} c@(Conflict m o y)
+resolve cfg@Config {..} c@(Conflict m o y)
+  | all Toks.space (concat [m, o, y]) && cfgSpaces /= SpacesNormal =
+    resolveSpace cfg c
   | m == o && o == y = Ok o
   | m == o && cfgResolveSeparate = Ok y
   | o == y && cfgResolveSeparate = Ok m
   | m == y && cfgResolveOverlaps = Ok m
 resolve _ x = x
 
+-- TODO: there might be a bit of interplay between the spaces handling and
+-- separate/overlapped conflict resolution -- e.g., what if someone wants to
+-- merge overlapping edits in text but separate edits in spaces? At this point
+-- that might be ignorable.
+resolveSpace Config {..} c@(Conflict m o y)
+  | m == o && o == y = Ok o
+  | otherwise =
+    case cfgSpaces of
+      SpacesConflict -> c
+      SpacesMy -> Ok m
+      SpacesOld -> Ok o
+      SpacesYour -> Ok y
+      _ -> error "spaces resolution failed"
+
+resolveSpaces _ x = x
+
 merge cfg@Config {..} ms ys =
   regroup
     . map (resolve cfg)

Opts.hs

@@ -38,13 +38,15 @@ tokenizer =
     ]
 
 data Spaces
-  = SpacesConflict
+  = SpacesNormal
+  | SpacesConflict
   | SpacesMy
   | SpacesOld
   | SpacesYour
-  deriving (Show)
+  deriving (Show, Eq)
 
 spaceMode x
+  | x `isPrefixOf` "normal" = Right SpacesNormal
   | x `isPrefixOf` "conflict" = Right SpacesConflict
   | x `isPrefixOf` "my" = Right SpacesMy
   | x `isPrefixOf` "old" = Right SpacesOld
@@ -53,7 +55,7 @@ spaceMode x
     Left
       $ "could not parse value `"
           ++ x
-          ++ "', use one of `conflict', `my', `old', and `your'"
+          ++ "', use one of `normal', `conflict', `my', `old', and `your'"
 
 data Config = Config
   { cfgTokenizer :: Tokenizer
@@ -75,10 +77,10 @@ config = do
     option (eitherReader spaceMode)
       $ long "spaces"
           <> short 's'
-          <> metavar "(conflict|my|old|your)"
+          <> metavar "(normal|conflict|my|old|your)"
           <> help
-               "mode of merging the spaces; instead of conflict one may choose to default the space from the source files (default: conflict)"
+               "mode of merging the space-only changes; instead of usual resolution one may choose to always conflict or to default the space from the source files (default: normal)"
-          <> value SpacesConflict
+          <> value SpacesNormal
   cfgContext <-
     option auto
       $ long "expand-context"

Toks.hs

@@ -23,6 +23,9 @@ unmarkSpace ('.':s) = s
 unmarkSpace ('|':s) = s
 unmarkSpace _ = error "wat"
 
+space ('.':_) = True
+space _ = False
+
 split =
   unlines
     . map (concatMap escape . markSpace)