[Haskell-beginners] Re: Need help to edit the Haskell script in Winhugs and documentation.

These look like homework questions. If these are homework questions, while we are all here to help, we cannot help you unless you provide more information on why you are stuck. In this regard, the following HaskellWiki article may be of assistance: Homework help - HaskellWiki http://haskell.org/haskellwiki/Homework_help -- Benjamin L. Russell On Mon, 30 Mar 2009 17:52:34 +0900, Benjamin L.Russell wrote:

Could you please describe your question more specifically?

-- Benjamin L. Russell

On Sat, 28 Mar 2009 16:48:47 +0000, RAJESH DALSANIYA wrote:

...

* *

*Both sections relate to the case study: Index for a document of text.*

* *

*SECTION A: *

* *

*Given the attached Haskell code which produces an index of words, make the following alterations by modifying existing functions and including new functions where necessary ? parts 1) to 5):*

* *

*1) **Where a word occurs N times on the same line, ensure that the line number occurs n times in the index entry for that word. *

* *

*2) **Allow words to be hyphenated and treat a hyphenated word as a single word. However, for those words which are split over two lines, treat a split word as a single word without the hyphen. *

* *

*3) **Treat a capitalised word (one or more capitals) as being different from the word in all lower case (but they should still be sorted alphabetically) ? unless it is at the start of a sentence with only the initial letter capitalised. A sentence is terminated by a ‘.’, ‘?’ or ‘!’. *

* *

*4) **Make the output more readable in the form of an index table in columns with appropriate spacing and without brackets. *

* *

*5) **Include a user-friendly menu, so that the user can choose input/output file names or default files, and choose to rerun or exit. *

* *

*Parts 1) to 5) may be developed in any order. *

* *

* *

*SECTION B:*

* *

*6) **For your version of function, makeIndex (only), show how an alternative ordering of the composed functions would provide a more efficient execution of makeIndex. Justify your answer. *

* *

*7) **For the parts 1) to 5) above that you have attempted, discuss the use you have made of a) higher-order functions, b) list comprehension, c) monadic input/output, d) functional composition, and/or e) partial parameterisation (or Curried functions). Include an evaluation of how useful your use of these concepts has been. *

* *

* * * *

*import Prelude*

* *

*type Doc = String*

*type Line = String*

*type Word = String *

* *

*makeIndex :: Doc -> [ ([Int], Word) ]*

* *

*makeIndex*

* = shorten . -- [([Int], Word)] -> [([Int], Word)]*

* amalgamate .-- [([Int], Word)] -> [([Int], Word)]*

* makeLists . -- [(Int, Word)] -> [([Int], Word)]*

* sortLs . -- [(Int, Word)] -> [(Int, Word)]*

* allNumWords .-- [(Int, Line)] -> [(Int, Word)]*

* numLines . -- [Line] -> [(Int, Line)]*

* splitUp -- Doc -> [Line]*

* *

*splitUp :: Doc -> [Line]*

* *

*splitUp [] = []*

*splitUp text*

* = takeWhile (/='\n') text : -- first line*

* (splitUp . -- splitup other lines*

* dropWhile (==’\n’) . -- delete 1st newline(s)*

* dropWhile (/='\n')) text -- other lines*

* *

*numLines :: [Line] -> [(Int, Line)]*

* *

*numLines lines -- list of pairs of *

* = zip [1 .. length lines] lines -- line no. & line*

* *

*-- for each line*

*-- a) split into words*

*-- b) attach line no. to each word*

* *

*splitWords :: Line -> [Word] -- a)*

* *

*splitWords [] = []*

*splitWords line *

* = takeWhile isLetter line : -- first word in line*

* (splitWords . -- split other words*

* dropWhile (not.isLetter) . -- delete separators*

* dropWhile isLetter) line -- other words*

* where*

* isLetter ch*

* = (‘a’<=ch) && (ch<=’z’)*

* || (‘A’<=ch) && (ch<=’Z’)*

* *

*numWords :: (Int, Line) -> [(Int, Word)] -- b)*

* *

*numWords (number, line)*

* = map addLineNum ( splitWords line) -- all line pairs*

* where*

* addLineNum word = (number, word) -- a pair*

* *

*allNumWords :: [(Int, Line)] -> [(Int, Word)]*

* *

*allNumWords = concat . map numWords -- doc pairs *

* *

*sortLs :: [(Int, Word)] -> [(Int, Word)]*

* *

*sortLs [ ] = [ ]*

*sortLs (a:x)*

* = sortLs [b | b <- x, compare b a] -- sort 1st half*

* ++ [a] ++ -- 1st in middle*

* sortLs [b | b <- x, compare a b] -- sort 2nd half*

* where*

* compare (n1, w1) (n2, w2)*

* = (w1 < w2) -- 1st word less*

* || (w1 == w2 && n1 < n2) -- check no. *

* *

*makeLists :: [(Int, Word)] -> [([Int], Word)]*

* *

*makeLists *

* = map mk -- all pairs*

* where mk (num, word) = ([num], word)*

* -- list of single no.*

* *

*amalgamate :: [([Int], Word)] -> [([Int], Word)]*

* *

*amalgamate [ ] = [ ]*

*amalgamate [a] = [a]*

*amalgamate ((n1, w1) : (n2, w2) : rest)-- pairs of pairs*

* | w1 /= w2 = (n1, w1) : amalgamate ((n2, w2) : rest)*

* | otherwise = amalgamate ((n1 ++ n2, w1) : rest)*

* -- if words are same grow list of numbers*

* *

*shorten :: [([Int], Word)] -> [([Int], Word)]*

* *

*shorten*

* = filter long -- keep pairs >4*

* where*

* long (num, word) = length word > 4 -- check word >4*

* * -- Benjamin L. Russell / DekuDekuplex at Yahoo dot com http://dekudekuplex.wordpress.com/ Translator/Interpreter / Mobile: +011 81 80-3603-6725 "Furuike ya, kawazu tobikomu mizu no oto." -- Matsuo Basho^