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| author | Jesse Rosenthal <jrosenthal@jhu.edu> | 2014-08-06 09:56:33 -0400 |
|---|---|---|
| committer | Jesse Rosenthal <jrosenthal@jhu.edu> | 2014-08-06 11:20:41 -0400 |
| commit | 06488c95fa9cf29c1b735c86764968796690e948 (patch) | |
| tree | e9492e9190748e8759ba784ecbab3f5ed244e6ff | |
| parent | 3bc2ea4cf753997738f0247be854b04ca91456e3 (diff) | |
Add a note on how `mapD` works.
| -rw-r--r-- | src/Text/Pandoc/Readers/Docx/Parse.hs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/Text/Pandoc/Readers/Docx/Parse.hs b/src/Text/Pandoc/Readers/Docx/Parse.hs index 5cfe50c5c..96210c31a 100644 --- a/src/Text/Pandoc/Readers/Docx/Parse.hs +++ b/src/Text/Pandoc/Readers/Docx/Parse.hs @@ -100,6 +100,9 @@ maybeToD Nothing = throwError DocxError concatMapM :: (Monad m) => (a -> m [b]) -> [a] -> m [b] concatMapM f xs = liftM concat (mapM f xs) + +-- This is similar to `mapMaybe`: it maps a function returning the D +-- monad over a list, and only keeps the non-erroring return values. mapD :: (a -> D b) -> [a] -> D [b] mapD f xs = let handler x = (f x >>= (\y-> return [y])) `catchError` (\_ -> return []) |