From 5ecf35a1ec67727c695505b1c14e8ea7794e3117 Mon Sep 17 00:00:00 2001
From: Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
Date: Thu, 25 Dec 2014 15:18:40 +0530
Subject: [PATCH] initial version of the assignment solution. WIP

---
 hw7/JoinList.hs | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 hw7/Scrabble.hs |  1 -
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/hw7/JoinList.hs b/hw7/JoinList.hs
index 916597e..e5633d5 100644
--- a/hw7/JoinList.hs
+++ b/hw7/JoinList.hs
@@ -1,8 +1,14 @@
 {-# OPTIONS_GHC -Wall #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+
 module JoinList where
 
 import Data.Monoid
 import Sized
+import Scrabble
+import Buffer
+import Editor
 
 data JoinList m a = Empty
                   | Single m a
@@ -62,3 +68,46 @@ takeJ n v@(Append t l r) | n > getSize (size t) = v
                                        Append ((tag l) `mappend` (tag rt)) l rt
                          where leftSize = getSize . size . tag $ l
 
+
+-- exercise 3 (Scrabble.hs)
+scoreLine :: String -> JoinList Score String
+scoreLine l = let scores = map scoreString . words $ l
+                  scoresAndWords = zip scores (words l)
+              in
+                foldr (+++) Empty $ map (\(s, w) -> Single s w) scoresAndWords
+
+-- exercise 4
+-- instance (Monoid a, Monoid b) => Monoid (a,b) where
+--   mempty = (mempty, mempty)
+--   (a,b) `mappend` (c,d) = ((a `mappend` c), (b `mappend` d))
+
+
+instance Buffer (JoinList (Score, Size) String) where
+  toString (Empty) = ""
+  toString (Single _ s) = s
+  toString (Append _ l r) = toString l ++ toString r
+
+  fromString s = Single (scoreString s, (Size  (length s))) s
+  line n b = indexJ n b
+  replaceLine n l b = let pre = takeJ (n - 1) b
+                          post = dropJ n b
+                          (Append m1 _ _) = scoreLine l
+                      in
+                       pre +++ (Single (m1, Size (length l)) l) +++ post
+  numLines = \x -> case x of
+                     Empty -> 0
+                     Single _ _ -> 1
+                     Append _ l r -> numLines l + numLines r
+
+  value = \x -> case x of
+                  Empty -> 0
+                  Single (_, m2) _ -> getSize . size $ m2
+                  Append (_, m2) _ _ -> getSize . size $ m2
+
+main = runEditor editor $ Single (Score 244,Size 177) "This buffer is for notes you don't want to save, and for evaluation of steam valve coefficients. To load a different file, type the character L followed by the name of the file."
+--         [ "This buffer is for notes you don't want to save, and for"
+--         , "evaluation of steam valve coefficients."
+--         , "To load a different file, type the character L followed"
+--         , "by the name of the file."
+--         ]
+-- "This buffer is for notes you don't want to save, and for evaluation of steam valve -- coefficients. To load a different file, type the character L followed by the name of the file."
diff --git a/hw7/Scrabble.hs b/hw7/Scrabble.hs
index b2dd38f..b08f6af 100644
--- a/hw7/Scrabble.hs
+++ b/hw7/Scrabble.hs
@@ -1,6 +1,5 @@
 {-# OPTIONS_GHC -Wall #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-
 module Scrabble where
 
 import Data.Monoid
-- 
2.37.2