From 98329e0a3dd4f78b5d815ac3896272ec70904901 Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Thu, 11 Dec 2025 10:28:11 +0100
Subject: Add remaining haskell book exercises

---
 Haskell-book/24/LearnParsers/src/Text/Fractions.hs | 31 ++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Haskell-book/24/LearnParsers/src/Text/Fractions.hs

(limited to 'Haskell-book/24/LearnParsers/src/Text')

diff --git a/Haskell-book/24/LearnParsers/src/Text/Fractions.hs b/Haskell-book/24/LearnParsers/src/Text/Fractions.hs
new file mode 100644
index 0000000..f09efc0
--- /dev/null
+++ b/Haskell-book/24/LearnParsers/src/Text/Fractions.hs
@@ -0,0 +1,31 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Text.Fractions where
+
+import Control.Applicative
+import Data.Ratio ((%))
+import Text.Trifecta
+
+badFraction = "1/0"
+
+alsoBad = "10"
+
+shouldWork = "1/2"
+
+shouldAlsoWork = "2/1"
+
+parseFraction :: Parser Rational
+parseFraction = do
+    numerator <- decimal
+    char '/'
+    denominator <- decimal
+    return (numerator % denominator)
+
+virtuousFraction :: Parser Rational
+virtuousFraction = do
+    numerator <- decimal
+    char '/'
+    denominator <- decimal
+    case denominator of
+      0 -> fail "Denominator cannot be zero"
+      _ -> return $ numerator % denominator
-- 
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