Range expansion: Difference between revisions
→Haskell – With a parser: Added FlexibleContents to enable parsing, applied hlint, hindent
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(→Haskell – With a parser: Added FlexibleContents to enable parsing, applied hlint, hindent) |
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where (a, b) = break (== delim) l</lang>
===With a parser===
<lang haskell>
import Control.Applicative (Applicative((<*>), (*>)), (<$>))
import Text.Parsec
expandRange :: String -> Maybe [Int]
expandRange = either (const Nothing) Just . parse rangeParser ""
rangeParser
:: (Enum a, Read a, Stream s m Char)
=> ParsecT s u m [a]
rangeParser = concat <$> (item `sepBy` char ',')
where
item = do
n2 <-
return [n1 .. n2]
num = read
dot = (.) . (.)
main :: IO ()
main = print $ expandRange "-6,-3--1,3-5,7-11,14,15,17-20"</lang>
{{Out}}
<pre>Just [-6,-3,-2,-1,3,4,5,7,8,9,10,11,14,15,17,18,19,20]</pre>
=={{header|Icon}} and {{header|Unicon}}==
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