47 lines
1.3 KiB
Haskell
47 lines
1.3 KiB
Haskell
import Text.ParserCombinators.Parsec
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import System.Environment
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-- Each parser takes in a sequence of Chars and returns either
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-- * an array of Strings ([String])
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-- * an array of arrays of Strings ([String])
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csvFile :: GenParser Char st [[String]]
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-- A csv file contains 0 or more lines and is terminated by the end of the file
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csvFile = do
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result <- many line -- The result is an array of an array of Strings, i.e. [[String]]
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eof -- match end of file
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return result
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line :: GenParser Char st [String]
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-- A line is a comma separated list of values, ending with a newline character
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line = do
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result <- cells
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char '\n' -- end of line, only works in Linux or OSX formatted files
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return result
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cells :: GenParser Char st [String]
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cells = do
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first <- cellContent
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next <- remainingCells
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return (first : next)
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remainingCells :: GenParser Char st [String]
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remainingCells = do
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(char ',' >> cells) -- found a comma, so more cells
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<|> (return []) -- No comma, so we wrap up an empty array
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cellContent :: GenParser Char st String
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cellContent =
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many (noneOf ",\n") -- Matches any character that is not a comma or newline
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parseCSV :: String -> Either ParseError [[String]]
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parseCSV input = parse csvFile "(unknown)" input
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main = do
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args <- getArgs
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p <- parseFromFile csvFile (head args)
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case p of
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Left err -> print err
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Right csv -> print csv
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