From 8260355fb3f33df740336431f49546ec581eef92 Mon Sep 17 00:00:00 2001
From: Jaro <jaro@argonaut-constellation.org>
Date: Sat, 25 Feb 2023 13:15:49 +0100
Subject: [PATCH] Store span index in ResolvedSpan.

---
 src/Data/Text/ParagraphLayout/Plain.hs        | 15 +++++++++++++--
 src/Data/Text/ParagraphLayout/ResolvedSpan.hs |  8 ++++++--
 test/Data/Text/ParagraphLayout/SpanData.hs    |  9 ++++++---
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/src/Data/Text/ParagraphLayout/Plain.hs b/src/Data/Text/ParagraphLayout/Plain.hs
index bee2bcf..01f1cef 100644
--- a/src/Data/Text/ParagraphLayout/Plain.hs
+++ b/src/Data/Text/ParagraphLayout/Plain.hs
@@ -93,6 +93,15 @@ data WithSpan a = WithSpan RS.ResolvedSpan a
 instance Functor WithSpan where
     fmap f (WithSpan s a) = WithSpan s (f a)
 
+splitBySpanIndex :: [WithSpan a] -> [[a]]
+splitBySpanIndex xs = [getBySpanIndex i xs | i <- [0..]]
+
+getBySpanIndex :: Int -> [WithSpan a] -> [a]
+getBySpanIndex idx xs = map contents $ filter matchingIndex $ xs
+    where
+        matchingIndex (WithSpan rs _) = (RS.spanIndex rs) == idx
+        contents (WithSpan _ x) = x
+
 spanRects :: SpanLayout -> [Rect Int32]
 spanRects (SpanLayout frags) = map fragmentRect frags
 
@@ -190,9 +199,11 @@ shapeRun (WithSpan rs run) = shape font buffer features
 resolveSpans :: Paragraph -> [RS.ResolvedSpan]
 resolveSpans (Paragraph arr off spans opts) = do
     let texts = cuts arr off spans
-    (s, t) <- zip spans texts
+    let indexes = [0..]
+    (s, t, i) <- zip3 spans texts indexes
     return RS.ResolvedSpan
-        { RS.spanText = t
+        { RS.spanIndex = i
+        , RS.spanText = t
         , RS.spanFont = paragraphFont opts
         , RS.spanLineHeight = paragraphLineHeight opts
         , RS.spanLanguage = spanLanguage s
diff --git a/src/Data/Text/ParagraphLayout/ResolvedSpan.hs b/src/Data/Text/ParagraphLayout/ResolvedSpan.hs
index bc4485e..110c2cf 100644
--- a/src/Data/Text/ParagraphLayout/ResolvedSpan.hs
+++ b/src/Data/Text/ParagraphLayout/ResolvedSpan.hs
@@ -9,9 +9,13 @@ import Data.Text.ParagraphLayout.LineHeight
 -- | Internal structure containing resolved values that may be shared with
 -- other spans across the paragraph.
 data ResolvedSpan = ResolvedSpan
-    { spanText :: Text
+    { spanIndex :: Int
+    , spanText :: Text
     , spanFont :: Font
     , spanLineHeight :: LineHeight
     , spanLanguage :: String
     }
-    deriving (Eq, Show)
+    deriving (Show)
+
+instance Eq ResolvedSpan where
+    a == b = spanIndex a == spanIndex b
diff --git a/test/Data/Text/ParagraphLayout/SpanData.hs b/test/Data/Text/ParagraphLayout/SpanData.hs
index 2d9d987..ed23fe6 100644
--- a/test/Data/Text/ParagraphLayout/SpanData.hs
+++ b/test/Data/Text/ParagraphLayout/SpanData.hs
@@ -12,7 +12,8 @@ import Data.Text.ParagraphLayout.ResolvedSpan (ResolvedSpan(..))
 
 emptySpan :: Font -> ResolvedSpan
 emptySpan font = ResolvedSpan
-    { spanText = pack ""
+    { spanIndex = 0
+    , spanText = pack ""
     , spanFont = font
     , spanLineHeight = Normal
     , spanLanguage = "en"
@@ -20,7 +21,8 @@ emptySpan font = ResolvedSpan
 
 czechHello :: Font -> ResolvedSpan
 czechHello font = ResolvedSpan
-    { spanText = pack "Ahoj, světe!"
+    { spanIndex = 0
+    , spanText = pack "Ahoj, světe!"
     , spanFont = font
     , spanLineHeight = Normal
     , spanLanguage = "cs"
@@ -28,7 +30,8 @@ czechHello font = ResolvedSpan
 
 serbianMixedScript :: Font -> ResolvedSpan
 serbianMixedScript font = ResolvedSpan
-    { spanText = pack "Vikipedija (Википедија)"
+    { spanIndex = 0
+    , spanText = pack "Vikipedija (Википедија)"
     , spanFont = font
     , spanLineHeight = Normal
     , spanLanguage = "sr"
-- 
2.30.2