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|
{- Streaming JSON output.
-
- Copyright 2011 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
module Utility.JSONStream (
start,
add,
end
) where
import Text.JSON
{- Text.JSON does not support building up a larger JSON document piece by
- piece as a stream. To support streaming, a hack. The JSObject is converted
- to a string with its final "}" is left off, allowing it to be added to
- later. -}
start :: JSON a => [(String, a)] -> String
start l
| last s == endchar = init s
| otherwise = bad s
where
s = encodeStrict $ toJSObject l
add :: JSON a => [(String, a)] -> String
add l
| head s == startchar = ',' : drop 1 s
| otherwise = bad s
where
s = start l
end :: String
end = [endchar, '\n']
startchar :: Char
startchar = '{'
endchar :: Char
endchar = '}'
bad :: String -> a
bad s = error $ "Text.JSON returned unexpected string: " ++ s
|
