<div dir="ltr"><div><div>Well I went ahead and completed that function, but I didn't use your data types exactly, but it should be a one to one mapping, just modify this function with your constructors.<br><br>radix2things :: RadixTree -> [(Text, (Maybe Int, Maybe Int))]<br>radix2things r = conv' mempty r<br> where<br> conv' :: Text -> RadixTree -> [(Text, (Maybe Int, Maybe Int))]<br> conv' acc (Leaf (Times a b)) = [(acc, (a, b))] <br> conv' acc r@(Node ns) = P.concatMap (\(t,r) -> conv' (acc <> t) r) ns<br><br></div>And you'll get a result like:<br><br>*Main> case decode teststr of Nothing -> undefined; Just a -> conv a<br>[("a2b2",(Just 4,Just 5)),("ab",(Just 1,Just 2)),("acd",(Just 3,Nothing))]<br><br></div>Good luck.<br><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Aug 27, 2015 at 4:31 PM, Adam Flott <span dir="ltr"><<a href="mailto:adam@adamflott.com" target="_blank">adam@adamflott.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I am attached to the data structure as it's what our Thrift message<br>
spits out and has to be mapped that way for the down stream consumers.<br>
<div><div class="h5"><br>
<br>
On 08/27/2015 01:45 PM, David McBride wrote:<br>
> I was trying this but ran into a bit of trouble. Are you super<br>
> attached to that data structure? I would expect a radix tree as<br>
> you've described it to look more like this:<br>
><br>
> data RadixTree = Node [(Text, RadixTree)] | Leaf Times<br>
> data Times = Times (Maybe Int) (Maybe Int)<br>
><br>
> In which case it is much easier to write the json instances. From<br>
> there you shouldn't have too much of a problem writing a recursive<br>
> function to do the rest, without dealing with all the aeson stuff at<br>
> the same time. Here's what I ended up with (I think it could be<br>
> cleaned up a bit).<br>
><br>
> import Control.Monad<br>
> import Data.Text as T<br>
> import Data.Aeson<br>
> import Data.HashMap.Strict as HM<br>
> import Data.Vector as V hiding (mapM)<br>
><br>
> data RadixTree = Node [(Text, RadixTree)] | Leaf Times deriving Show<br>
> data Times = Times (Maybe Int) (Maybe Int) deriving Show<br>
><br>
> instance FromJSON RadixTree where<br>
> parseJSON (Object o) = do<br>
> let els = HM.toList o<br>
> contents <- mapM (\(t,v) -> do v' <- parseJSON v; return (t, v'))<br>
> (HM.toList o)<br>
> return $ Node contents<br>
> parseJSON a@(Array _) = Leaf <$> parseJSON a<br>
> parseJSON _ = mzero<br>
><br>
> instance FromJSON Times where<br>
> parseJSON (Array v) | (V.length v) >= 2 =<br>
> let v0 = v V.! 0<br>
> v1 = v V.! 1<br>
> in Times <$> parseJSON v0 <*> parseJSON v1<br>
> parseJSON _ = mzero<br>
><br>
> {-<br>
> tree2things :: RadixTree -> [(Text, (Maybe Int, Maybe Int))]<br>
> tree2things (Node xs) = _<br>
> tree2things (Leaf t) = _<br>
> -}<br>
><br>
> On Thu, Aug 27, 2015 at 11:30 AM, Adam Flott <<a href="mailto:adam@adamflott.com">adam@adamflott.com</a><br>
</div></div><div><div class="h5">> <mailto:<a href="mailto:adam@adamflott.com">adam@adamflott.com</a>>> wrote:<br>
><br>
> On 08/27/2015 11:18 AM, Karl Voelker wrote:<br>
> > On Thu, Aug 27, 2015, at 08:04 AM, Adam Flott wrote:<br>
> >> data Things = MkThings {<br>
> >> thing :: TL.Text,<br>
> >> times :: ThingTimes<br>
> >> } deriving (Show, Eq, Typeable)<br>
> >><br>
> >> data ThingTimes = MkThingtimes {<br>
> >> ml :: V.Vector Times<br>
> >> } deriving (Show, Eq, Typeable)<br>
> >><br>
> >> data Times = MkTimes {<br>
> >> t1 :: Maybe Int32,<br>
> >> t2 :: Maybe Int32<br>
> >> } deriving (Show, Eq, Typeable)<br>
> >><br>
> >> -- radix.json --<br>
> >> {<br>
> >> "a" : {<br>
> >> "b" : [ 1, 2 ],<br>
> >> "c" : {<br>
> >> "d" : [ 3, null ]<br>
> >> }<br>
> >> },<br>
> >> "a2" : { "b2" : [ 4, 5 ] }<br>
> >> }<br>
> >> -- radix.json --<br>
> > It looks like your input file has Things nested inside Things,<br>
> but your<br>
> > data types don't allow for that. Is that intentional? What value<br>
> is that<br>
> > example input supposed to parse to?<br>
><br>
> Vector [<br>
> MkThings "ab" (MkThingTimes (Vector [ Just 1, Just 2 ])),<br>
> MkThings "abcd" (MkThingsTimes (Vector [ Just 3, Nothing))<br>
> MkThings "a2b2" (MkThingTimes (Vector [ Just 4, Just 5 ])) ]<br>
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