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module PhoneNumber where
import Control.Applicative
import Text.Trifecta
-- 4. Write a parser for US/Canada phone numbers with varying formats.
-- Cf. Wikipeida's article on "National conventions for writing telephone
-- numbers". You are encouraged to adapt the exercise to your locality's
-- conventions if they are not part of the NNAP scheme.
-- aka area code
type NumberingPlanArea = Int
type Exchange = Int
type LineNumber = Int
data PhoneNumber = PhoneNumber NumberingPlanArea Exchange LineNumber
deriving (Eq, Show)
parsePhone :: Parser PhoneNumber
parsePhone = do
_ <- optional ((try $ char '(') <|> (try (char '1' >> char '-')))
area <- count 3 digit
_ <- optional $ (try $ char ')')
_ <- optional $ (try $ char ' ') <|> (try $ char '-')
exchange <- count 3 digit
_ <- optional $ (char ' ') <|> (char '-')
lineNumber <- decimal
return $ PhoneNumber (read area) (read exchange) (fromIntegral lineNumber)
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