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comparison exercises/src/AdditionParser.hs @ 29:53732b9605c7

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add AdditionParser
author Markus Kaiser <markus.kaiser@in.tum.de>
date Fri, 11 Jan 2013 00:49:48 +0100
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28:e0ae5d8b55d3 29:53732b9605c7
1 module AdditionParser where
2
3 import Data.Char
4 import Parser
5
6 digit :: Parser Char Char
7 digit = one isDigit
8
9 number :: Parser Char String
10 number = list1(one isDigit)
11
12 addition :: Parser Char [String]
13 addition = number *** optional (item '+' *** addition >>> snd) >>> ints
14 where
15 ints (x, Just y) = x : y
16 ints (x, _) = [x]
17
18 test = addition "2134+123+1+2+3"