From 0f5dfa9a2b6865dc46ef926983c64b2ab11fa3d1 Mon Sep 17 00:00:00 2001
From: Jaro <jaro@argonaut-constellation.org>
Date: Tue, 21 Feb 2023 22:01:12 +0100
Subject: [PATCH] Use infix operators for constructing test data.

---
 balkon.cabal                                  |  1 +
 .../ParagraphLayout/ParagraphConstruction.hs  | 64 +++++++++++++++++++
 .../Text/ParagraphLayout/ParagraphData.hs     | 51 ++-------------
 3 files changed, 72 insertions(+), 44 deletions(-)
 create mode 100644 test/Data/Text/ParagraphLayout/ParagraphConstruction.hs

diff --git a/balkon.cabal b/balkon.cabal
index c8e1d89..2475a4a 100644
--- a/balkon.cabal
+++ b/balkon.cabal
@@ -130,6 +130,7 @@ test-suite balkon-test
     other-modules:
         Data.Text.ParagraphLayoutSpec,
         Data.Text.ParagraphLayout.FontLoader,
+        Data.Text.ParagraphLayout.ParagraphConstruction,
         Data.Text.ParagraphLayout.ParagraphData,
         Data.Text.ParagraphLayout.PlainSpec,
         Data.Text.ParagraphLayout.RectSpec,
diff --git a/test/Data/Text/ParagraphLayout/ParagraphConstruction.hs b/test/Data/Text/ParagraphLayout/ParagraphConstruction.hs
new file mode 100644
index 0000000..a9af880
--- /dev/null
+++ b/test/Data/Text/ParagraphLayout/ParagraphConstruction.hs
@@ -0,0 +1,64 @@
+-- | Infix operators for readable construction of paragraphs as testing input.
+--
+-- Example construction:
+-- @"ignored prefix" |< "en"~"one two " >|< "ja"~"三四" >| "ignored suffix"@
+--
+-- Special syntax for paragraphs with no contents:
+-- @"ignored prefix" |<>| "ignored suffix"@
+--
+-- Please note that this form of construction is inefficient for longer text.
+module Data.Text.ParagraphLayout.ParagraphConstruction
+    ((>|)
+    ,(>|<)
+    ,(|<)
+    ,(|<>|)
+    ,(~)
+    )
+where
+
+import Data.Text (append, pack)
+import Data.Text.Foreign (lengthWord8)
+import Data.Text.Internal (Text(Text))
+import Data.Text.ParagraphLayout.Plain
+    (Paragraph(Paragraph)
+    ,ParagraphOptions()
+    ,Span(Span)
+    )
+
+-- | Create first span with optional ignored suffix.
+infixr 5 >|
+(>|) :: (String, String) -> String -> (Text, [Span])
+(spanText, spanLanguage) >| ignoredSuffix = (newText, newSpans)
+    where
+        newSpans = [Span (fromIntegral $ lengthWord8 packedSpanText) spanLanguage]
+        newText = append packedSpanText packedSuffix
+        packedSpanText = pack spanText
+        packedSuffix = pack ignoredSuffix
+
+-- Create next span.
+infixr 5 >|<
+(>|<) :: (String, String) -> (Text, [Span]) -> (Text, [Span])
+(spanText, spanLanguage) >|< (oldText, oldSpans) = (newText, newSpans)
+    where
+        newSpans = Span (fromIntegral $ lengthWord8 packedText) spanLanguage : oldSpans
+        newText = append packedText oldText
+        packedText = pack spanText
+
+-- Add optional ignored prefix and wrap in a `Paragraph`.
+infixr 5 |<
+(|<) :: String -> (Text, [Span]) -> ParagraphOptions -> Paragraph
+ignoredPrefix |< (oldText, spans) = Paragraph arr (fromIntegral off) spans
+    where
+        (Text arr offPrefix _) = append packedPrefix oldText
+        off = offPrefix + (lengthWord8 packedPrefix)
+        packedPrefix = pack ignoredPrefix
+
+-- Create a `Paragraph` with no spans, just two ignored texts.
+infixr 5 |<>|
+(|<>|) :: String -> String -> ParagraphOptions -> Paragraph
+ignoredPrefix |<>| ignoredSuffix = ignoredPrefix |< (pack ignoredSuffix, [])
+
+-- Combine language with text.
+infix 6 ~
+(~) :: String -> String -> (String, String)
+lang ~ txt = (txt, lang)
diff --git a/test/Data/Text/ParagraphLayout/ParagraphData.hs b/test/Data/Text/ParagraphLayout/ParagraphData.hs
index 7b7d0a8..672149b 100644
--- a/test/Data/Text/ParagraphLayout/ParagraphData.hs
+++ b/test/Data/Text/ParagraphLayout/ParagraphData.hs
@@ -7,57 +7,20 @@ module Data.Text.ParagraphLayout.ParagraphData
     )
 where
 
-import Data.Text (pack)
-import Data.Text.Internal (Text(Text))
-import Data.Text.ParagraphLayout.Plain
-    (Paragraph(Paragraph)
-    ,ParagraphOptions
-    ,Span(Span)
-    )
+import Data.Text.ParagraphLayout.ParagraphConstruction
+import Data.Text.ParagraphLayout.Plain (Paragraph, ParagraphOptions)
 
 emptyParagraph :: ParagraphOptions -> Paragraph
-emptyParagraph opts =
-    let (Text arr off _) = pack ""
-    in Paragraph
-        arr
-        (fromIntegral off)
-        []
-        opts
+emptyParagraph = "" |<>| ""
 
 emptySpanParagraph :: ParagraphOptions -> Paragraph
-emptySpanParagraph opts =
-    let (Text arr off _) = pack ""
-    in Paragraph
-        arr
-        (fromIntegral off)
-        [Span 0 "en"]
-        opts
+emptySpanParagraph = "" |< "en"~"" >| ""
 
 czechHelloParagraph :: ParagraphOptions -> Paragraph
-czechHelloParagraph opts =
-    let (Text arr off len) = pack "Ahoj, světe!"
-    in Paragraph
-        arr
-        (fromIntegral off)
-        [Span (fromIntegral len) "cs"]
-        opts
+czechHelloParagraph = "" |< "cs"~"Ahoj, světe!" >| ""
 
 mixedScriptSerbianParagraph :: ParagraphOptions -> Paragraph
-mixedScriptSerbianParagraph opts =
-    let (Text arr off len) = pack "Vikipedija (Википедија)"
-    in Paragraph
-        arr
-        (fromIntegral off)
-        [Span (fromIntegral len) "sr"]
-        opts
+mixedScriptSerbianParagraph = "" |< "sr"~"Vikipedija (Википедија)" >| ""
 
 mixedLanguageLTRParagraph :: ParagraphOptions -> Paragraph
-mixedLanguageLTRParagraph opts =
-    let (Text arr off _) = pack "Tak jsem tady, 世界!"
-    in Paragraph
-        arr
-        (fromIntegral off + 4)
-        [Span 11 "cs" -- this will contain the text "jsem tady, "
-        ,Span 7 "ja" -- this will contain the text "世界!"
-        ]
-        opts
+mixedLanguageLTRParagraph = "Tak " |< "cs"~"jsem tady, " >|< "ja"~"世界!" >| ""
-- 
2.30.2