3 files changed, 31 insertions(+), 12 deletions(-)

M balkon.cabal
A src/Data/Text/ParagraphLayout/Internal/ProtoRun.hs
M src/Data/Text/ParagraphLayout/Internal/Run.hs

@@ 139,6 139,7 @@ library balkon-internal
         Data.Text.ParagraphLayout.Internal.ParagraphLine,
         Data.Text.ParagraphLayout.Internal.ProtoFragment,
         Data.Text.ParagraphLayout.Internal.ProtoLine,
+        Data.Text.ParagraphLayout.Internal.ProtoRun,
         Data.Text.ParagraphLayout.Internal.Script
 
     build-depends:

@@ 0,0 1,15 @@
+module Data.Text.ParagraphLayout.Internal.ProtoRun (ProtoRun (..))
+where
+
+import Data.Text.Glyphize (Direction)
+
+import Data.Text.ParagraphLayout.Internal.Script
+import Data.Text.ParagraphLayout.Internal.Zipper
+
+-- | Intermediate structure for creating
+-- `Data.Text.ParagraphLayout.Internal.Run.Run` values.
+data ProtoRun = ProtoRun
+    { zipper :: Zipper
+    , direction :: Maybe Direction
+    , script :: ScriptCode
+    }

@@ 9,6 9,8 @@ import Data.Text.Foreign (dropWord8, lengthWord8, takeWord8)
 import Data.Text.Glyphize (Direction (..))
 import qualified Data.Text.ICU.Char as ICUChar
 
+import Data.Text.ParagraphLayout.Internal.ProtoRun (ProtoRun (ProtoRun))
+import qualified Data.Text.ParagraphLayout.Internal.ProtoRun as PR
 import Data.Text.ParagraphLayout.Internal.ResolvedSpan
 import Data.Text.ParagraphLayout.Internal.Script
 import Data.Text.ParagraphLayout.Internal.TextContainer


@@ 48,8 50,6 @@ instance SeparableTextContainer Run where
             o' = o + l - l'
     dropWhileEnd p r = r { runText = Text.dropWhileEnd p (runText r) }
 
-type ProtoRun = (Zipper, Maybe Direction, ScriptCode)
-
 -- | Represents a zipper that can advance by at least one character.
 data ZipperChoice = ZipperChoice
     { nextChar :: Char


@@ 75,14 75,15 @@ data Merged a = Incompatible | Merged a
 spanToRuns :: ResolvedSpan d -> [Run]
 spanToRuns s = snd $ mapAccumL run 0 $ protoRuns zipper
     where
-        zipper = start $ spanText s
-        run acc (z, d, sc) = let t = preceding z in
+        wholeText = spanText s
+        zipper = start wholeText
+        run acc pr = let t = preceding (PR.zipper pr) in
             ( acc + lengthWord8 t
             , Run
                 { runOffsetInSpan = acc
                 , runText = t
-                , runDirection = d
-                , runScript = Just sc
+                , runDirection = PR.direction pr
+                , runScript = Just $ PR.script pr
                 }
             )
 


@@ 93,22 94,24 @@ protoRuns' :: Zipper -> [ProtoRun] -> [ProtoRun]
 protoRuns' curZipper curRuns = case considerNext curZipper of
     Nothing -> curRuns
     Just choice ->
-        let headRun@(nextZipper, _, _) :| tailRuns = foldRun choice curRuns
-        in protoRuns' nextZipper (headRun : tailRuns)
+        let headRun :| tailRuns = foldRun choice curRuns
+        in protoRuns' (PR.zipper headRun) (headRun : tailRuns)
 
 foldRun :: ZipperChoice -> [ProtoRun] -> NonEmpty ProtoRun
 
 -- If there are no runs, create a new run with a single character.
-foldRun x [] = (continuingRun x, d, s) :| []
+foldRun x [] = ProtoRun (continuingRun x) d s :| []
     where
         d = charDirection (nextChar x)
         s = charScript (nextChar x)
 
-foldRun x (previousRun@(_, d1, s1) : tailRuns) =
+foldRun x (previousRun : tailRuns) =
     case (mergeDirections d1 d2, mergeScripts s1 s2) of
-        (Merged d, Merged s) -> (continuingRun x, d, s) :| tailRuns
-        _ -> (startingNewRun x, d2, s2) :| previousRun : tailRuns
+        (Merged d, Merged s) -> ProtoRun (continuingRun x) d s :| tailRuns
+        _ -> ProtoRun (startingNewRun x) d2 s2 :| previousRun : tailRuns
     where
+        d1 = PR.direction previousRun
+        s1 = PR.script previousRun
         d2 = charDirection (nextChar x)
         s2 = charScript (nextChar x)