module Lex where

import IO

whitespace :: String
whitespace = ['\n','\t',' ']

getWord :: String -> String
getWord [] = []
getWord (x:xs)
	| elem x whitespace = []
	| otherwise         = x : getWord xs

dropWord :: String -> String
dropWord [] = []
dropWord (x:xs)
	| elem x whitespace = (x:xs)
 	| otherwise         = dropWord xs

dropSpace :: String -> String
dropSpace [] = []
dropSpace (x:xs)
	| elem x whitespace = dropSpace xs
	| otherwise         = (x:xs)

splitWords :: String -> [String]
splitWords st = split (dropSpace st)

split :: String -> [String]
split [] = [] 
split st = (getWord st) : split (dropSpace (dropWord st))

testReadFile :: IO [String]
testReadFile = do
		   s <- readFile "c:/lexemes.txt"
		   g <- return(splitWords s)
		   return(findToken g)

findName :: [String] -> [String]
findName (x:y)
	| x == "<name>" = (y)
	| otherwise = ["not found"]

findToken :: [String] -> [String]
findToken st = do
			 (x:y) <- findName st
			 [y]