[Haskell-cafe] Trees (Rose Trees?)

hi I was curious as to whether my implementation of a Rose Tree and a sumTree function was correct. The aumTree adds up the elements of a tree. data Tree a = Leaf a | Node [Tree a] sumTree :: Tree Int - Int sumTree (Node []) = 0 sumTree (Node xs) = sum (map sumTree xs) The problem with

[Haskell-cafe] help

hi I am writing a basic Parser from scratch. So far I have functions;# removeSpaces# match - which checks if a string is a substring of another# orParser which combines two parser's abilities# Basic pasrers like... parseInt, parseTrue, parseFalse, parseBoolusing the orParser on True and

[Haskell-cafe] parsebinaryoperations

hi I have a function parseInt... which needs an error guard for when the input is not an Int. parseInt :: ParserparseInt [] = []parseInt xs = let (digits, rest) = span isDigit (removeSpace xs)in [(EInt (read digits), removeSpace rest)] Also... I have a function that does

[Haskell-cafe] help

hi I have a function parseInt... which needs an error guard for when the input is not an Int. parseInt :: ParserparseInt [] = []parseInt xs = let (digits, rest) = span isDigit (removeSpace xs)in [(EInt (read digits), removeSpace rest)] Also... I have a function that does this...

[Haskell-cafe] binaryop

hi sorry for vagueness. I am writing a basic Parser from scratch. So far I have functions; # removeSpaces # match - which checks if a string is a substring of another # orParser which combines two parser's abilities # Basic pasrers like... parseInt, parseTrue, parseFalse, parseBoolusing the

[Haskell-cafe] Need help please.

hi I am writing a basic Parser from scratch. So far I have functions;# removeSpaces# match - which checks if a string is a substring of another# orParser which combines two parser's abilities# Basic pasrers like... parseInt, parseTrue, parseFalse, parseBoolusing the orParser on True and

[Haskell-cafe] general

hi I have a problem. Function A is a function that passes its input into B Function B is a function that does something once. How do I make it so function A is done multiple times without adding a third function? Ryan _

[Haskell-cafe] general-revised

hi I have four functions below: What I want to do is have a way to parse more than one digit or more than one string head in ParseTrue. Any ideas... removeSpace:: String - StringremoveSpace = dropWhile (`elem` space) where space = [' '] match :: String - String - (Bool,

[Haskell-cafe] do... error

hi test :: Parser (Char,Char) test = do x - item item y - item return (x,y) How come this brings an error saying that after do {} it must end with an expression. Ryan _ Get free

[Haskell-cafe] annoying output

hi The code below does almost what I want but not quite! It outputs...parseInt 12444a gives... [(EInt 1,2444a),(EInt 2,444a),(EInt 4,44a),(EInt 4,4a),(EInt 4,a)] What I want is: [(EInt 12444, a)] data Expr = EInt {vInt :: Int} -- integer values | EBool {vBool :: Bool} -- boolean

[Haskell-cafe] parser

hi Can anyone advise me on how to check whether a string contains ints, chars, bools, etc 2345 + 6767 shoudl give IntAdd (2345) (6767) 2345 should give IntT 2345 Ryan _ Who's friends with who and co-starred in what?

[Haskell-cafe] matching

hi I have a matching problem... I am wanting to identify whether or not a string is an opening substring of another (ignoring leading spaces). I have this: word is a single word and str is a string. match :: String - String - (Bool, String)match word str | if removeSpace

[Haskell-cafe] isSpace

hi I am having trouble with a function that is supposed to eliminate spaces from the start of a String and return the resulting string. I reckon a dropWhile could be used but the isSpace bit is causing me problems... words :: String - String words a = case dropWhile isSpace a of

[Haskell-cafe] isSpace

HI I will try and explain it better. I am meaning to write a function that takes a string, apple and eliminates the spaces at the start ONLY. called removeSpace :: String - String I decided to use the function 'dropWhile' and another one 'isSpace' in the 'removeSpace'

[Haskell-cafe] missed clause???

hi I was testing my code when I came across a strange predicament. The input is a list of ints and a Results type which is of type [(int,...),(Int..)..]. I am comparing each int from the list to the first element in each member of results. But it works for 1-9 but not for 10

[Haskell-cafe] FW: please help... small problem

hi I've attempted to cut down this module... but I cannot see where... can someone help... Ryan thanks From: [EMAIL PROTECTED]: Subject: FW: please help... small problemDate: Fri, 9 Nov 2007 21:57:30 + sorry heres the code I always do that. From: [EMAIL PROTECTED]: Subject:

[Haskell-cafe] recursion issues...

hiya I was wondering how I would get the second function do recursively do the function for poolNews xs tried that and it fails. Ryan --Give wins, draws a rating. poolNews :: Result - PoolNews - PoolNews poolNews (a,b,c,d,e) (home,away,goaless,scoredraw) | c d =

[Haskell-cafe] please help... small problem

hi Is there anyway to cut down this code and to not use auxillary functons, but instead use pattern matching? The code basically splits up a list 'rslis' into a list of lists - but so each word is split up and the integers have been parsed. so [hi ryan 1,hi jeff 2] becomes [[hi,ryan 1],

[Haskell-cafe] FW: please help... small problem

sorry heres the code I always do that. From: [EMAIL PROTECTED]: Subject: please help... small problemDate: Fri, 9 Nov 2007 21:44:35 + hi Is there anyway to cut down this code and to not use auxillary functons, but instead use pattern matching? The code basically splits up a list

[Haskell-cafe] words function

hi I am trying to create a function that uses the words function... I am doing the same thing to each element in a list so I am using mapping techniques. Code... --Define the main first function rStrings2Results :: ([String] - String) - [[String]] - [String] rStrings2Results f(head:tail)

[Haskell-cafe] Help please

hello, I am struggling with rose trees in Haskell. I need to construct an algebraic data type definition for family trees and a representation of the tree below. Also I need to construct a function that returns a persons children when given both a family tree and a name. The same is needed but for

[Haskell-cafe] Rose Tree

Hello, I need help... I am having trouble with rose trees. 1 2 3 4 5 6 7 8910 11 That is the rose tree that I seek.

[Haskell-cafe] Java - Haskell adjustment

Hi, its Ryan here... I've just come from an intensive course in java and have been thrown into the imperative world of haskell. The problem that I have is extremely simple in java but I am having trouble adjusting my old mindset. A multiset is a collection of items. Each item may occur one