git.iko.soy/project-m36
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project-m36/src/bin/TutorialD/Interpreter/Export/CSV.hs
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1module TutorialD.Interpreter.Export.CSV where
2import ProjectM36.Relation.Show.CSV
3import TutorialD.Interpreter.Export.Base
4import TutorialD.Interpreter.RelationalExpr
5import TutorialD.Interpreter.Base
6import ProjectM36.Base
7import ProjectM36.Error
8import Text.Megaparsec.Text
9import qualified Data.ByteString.Lazy as BS
10import Control.Exception (try)
11import qualified Data.Text as T
13exportCSVP :: Parser RelVarDataExportOperator
14exportCSVP = do
15 reserved ":exportcsv"
16 exportExpr <- relExprP
17 path <- quotedString
18 return $ RelVarDataExportOperator exportExpr (T.unpack path) exportRelationCSV
20exportRelationCSV :: RelVarDataExportOperator -> Relation -> IO (Maybe RelationalError)
21exportRelationCSV (RelVarDataExportOperator _ pathOut _) rel = do
22 case relationAsCSV rel of
23 Left err -> return $ Just err
24 Right csvData -> do
25 writeResult <- try (BS.writeFile pathOut csvData) :: IO (Either IOError ())
26 case writeResult of
27 Left err -> return $ Just (ExportError $ T.pack (show err))
28 Right _ -> return Nothing