From 69e92e75ea01ea2631277c40c5b6fdc36e538337 Mon Sep 17 00:00:00 2001
From: Jaro <jaro@argonaut-constellation.org>
Date: Wed, 26 Apr 2023 10:05:55 +0200
Subject: [PATCH] Separate interface-independent constants.

---
 balkon.cabal                                  |  1 +
 .../Internal/ParagraphExtents.hs              | 26 +++++++++++++++++++
 .../Text/ParagraphLayout/Internal/Plain.hs    |  1 +
 .../Internal/Plain/ParagraphLayout.hs         | 22 ++--------------
 4 files changed, 30 insertions(+), 20 deletions(-)
 create mode 100644 src/Data/Text/ParagraphLayout/Internal/ParagraphExtents.hs

diff --git a/balkon.cabal b/balkon.cabal
index 51920dc..c8e172a 100644
--- a/balkon.cabal
+++ b/balkon.cabal
@@ -121,6 +121,7 @@ library balkon-internal
 
     -- Modules used purely internally and not in any tests.
     other-modules:
+        Data.Text.ParagraphLayout.Internal.ParagraphExtents,
         Data.Text.ParagraphLayout.Internal.ParagraphLine,
         Data.Text.ParagraphLayout.Internal.ProtoFragment,
         Data.Text.ParagraphLayout.Internal.Script
diff --git a/src/Data/Text/ParagraphLayout/Internal/ParagraphExtents.hs b/src/Data/Text/ParagraphLayout/Internal/ParagraphExtents.hs
new file mode 100644
index 0000000..bc6ca9a
--- /dev/null
+++ b/src/Data/Text/ParagraphLayout/Internal/ParagraphExtents.hs
@@ -0,0 +1,26 @@
+module Data.Text.ParagraphLayout.Internal.ParagraphExtents
+    ( paragraphOriginX
+    , paragraphOriginY
+    , containRects
+    , emptyRect
+    )
+where
+
+import Data.Text.ParagraphLayout.Internal.Rect
+
+paragraphOriginX :: (Num a) => a
+paragraphOriginX = 0
+
+paragraphOriginY :: (Num a) => a
+paragraphOriginY = 0
+
+emptyRect :: (Num a) => Rect a
+emptyRect = Rect
+    { x_origin = paragraphOriginX
+    , y_origin = paragraphOriginY
+    , x_size = 0
+    , y_size = 0
+    }
+
+containRects :: (Ord a, Num a) => [Rect a] -> Rect a
+containRects = foldr union emptyRect
diff --git a/src/Data/Text/ParagraphLayout/Internal/Plain.hs b/src/Data/Text/ParagraphLayout/Internal/Plain.hs
index c98c653..ce4ff1f 100644
--- a/src/Data/Text/ParagraphLayout/Internal/Plain.hs
+++ b/src/Data/Text/ParagraphLayout/Internal/Plain.hs
@@ -28,6 +28,7 @@ import Data.Text.ParagraphLayout.Internal.BiDiReorder
 import Data.Text.ParagraphLayout.Internal.Break
 import Data.Text.ParagraphLayout.Internal.Fragment
 import Data.Text.ParagraphLayout.Internal.LineHeight
+import Data.Text.ParagraphLayout.Internal.ParagraphExtents
 import Data.Text.ParagraphLayout.Internal.ParagraphOptions
 import Data.Text.ParagraphLayout.Internal.Plain.Paragraph
 import Data.Text.ParagraphLayout.Internal.Plain.ParagraphLayout
diff --git a/src/Data/Text/ParagraphLayout/Internal/Plain/ParagraphLayout.hs b/src/Data/Text/ParagraphLayout/Internal/Plain/ParagraphLayout.hs
index eb73c5b..70ee28b 100644
--- a/src/Data/Text/ParagraphLayout/Internal/Plain/ParagraphLayout.hs
+++ b/src/Data/Text/ParagraphLayout/Internal/Plain/ParagraphLayout.hs
@@ -6,8 +6,6 @@ module Data.Text.ParagraphLayout.Internal.Plain.ParagraphLayout
     , mapFragments
     , paragraphFragments
     , paragraphLayout
-    , paragraphOriginX
-    , paragraphOriginY
     , shapedRuns
     )
 where
@@ -15,6 +13,7 @@ where
 import Data.Int (Int32)
 
 import Data.Text.ParagraphLayout.Internal.Fragment
+import Data.Text.ParagraphLayout.Internal.ParagraphExtents
 import Data.Text.ParagraphLayout.Internal.Rect
 import Data.Text.ParagraphLayout.Internal.Span
 
@@ -26,23 +25,6 @@ data ParagraphLayout d = ParagraphLayout
     }
     deriving (Eq, Read, Show)
 
-paragraphOriginX :: (Num a) => a
-paragraphOriginX = 0
-
-paragraphOriginY :: (Num a) => a
-paragraphOriginY = 0
-
-empty :: (Num a) => Rect a
-empty = Rect
-    { x_origin = paragraphOriginX
-    , y_origin = paragraphOriginY
-    , x_size = 0
-    , y_size = 0
-    }
-
-containRects :: (Ord a, Num a) => [Rect a] -> Rect a
-containRects = foldr union empty
-
 -- | Wrap the given `SpanLayout`s and compute their containing rectangle.
 paragraphLayout :: [SpanLayout d] -> ParagraphLayout d
 paragraphLayout sls = ParagraphLayout pRect sls
@@ -51,7 +33,7 @@ paragraphLayout sls = ParagraphLayout pRect sls
 -- | A `ParagraphLayout` with an infinite number of empty spans.
 -- Useful as an identity element for `appendFragments`.
 emptyParagraphLayout :: ParagraphLayout d
-emptyParagraphLayout = ParagraphLayout empty $ repeat (SpanLayout [])
+emptyParagraphLayout = ParagraphLayout emptyRect $ repeat (SpanLayout [])
 
 -- | Remove fragments that do not match the given predicate.
 --
-- 
2.30.2