haskell/colonnade-old
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

improve docs for siphon a little more

Browse Source
This commit is contained in:
Andrew Martin 2017-12-15 09:36:31 -05:00
parent f115e7798b
commit 17b1473359
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
siphon/src/Siphon.hs
View File

@ -110,6 +110,9 @@ encodeCsvStreamUtf8 :: (Monad m, CE.Headedness h)
encodeCsvStreamUtf8 =
encodeCsvInternal escapeChar8 (B.singleton comma) (B.singleton newline)
-- | Streaming variant of 'encodeCsv'. This is particularly useful
-- when you need to produce millions of rows without having them
-- all loaded into memory at the same time.
encodeCsvStream :: (Monad m, CE.Headedness h)
=> CE.Colonnade h a Text
-> Stream (Of a) m r
@ -747,12 +750,17 @@ maxIndex = go 0 where
go !ix1 (SiphonAp (IndexedHeader ix2 _) _ apNext) =
go (max ix1 ix2) apNext
-- | Uses the argument to parse a CSV column.
headless :: (c -> Maybe a) -> Siphon CE.Headless c a
headless f = SiphonAp CE.Headless f (SiphonPure id)
-- | Uses the second argument to parse a CSV column whose
-- header content matches the first column exactly.
headed :: c -> (c -> Maybe a) -> Siphon CE.Headed c a
headed h f = SiphonAp (CE.Headed h) f (SiphonPure id)
-- | Uses the second argument to parse a CSV column that
-- is positioned at the index given by the first argument.
indexed :: Int -> (c -> Maybe a) -> Siphon Indexed c a
indexed ix f = SiphonAp (Indexed ix) f (SiphonPure id)