[Haskell-beginners] Nonsensical behavior with http-conduit, httpLbs

[Christopher Allen]

to add to my question adding a delay made it work:

main :: IO ()
main = do
  _ <- insertData
  threadDelay 1000000
  myTweet <- queryTweet
  print myTweet



On Thu, Apr 10, 2014 at 12:41 AM, Christopher Allen <cma at bitemyapp.com>wrote:

> Repro'd on GHC 7.8.1 and 7.6.3
>
> Original code is: https://github.com/bitemyapp/bloodhound/
>
> The code only works if I manually (out of band) run insertData (in a REPL)
> and then run main with the insertData invocation stripped out. If I run
> main with the insertData invocation included, it throws an exception (head)
> because the search results are empty.
>
> The behavior is as if queryTweet was executing after insertData deleted
> the index, but before it inserted the new data.
>
> The following is a stripped down example:
>
> insertData :: IO ()
> insertData = do
>   let encoded = encode exampleTweet
>   _ <- deleteExampleIndex
>   created <- createExampleIndex
>   docCreated <- indexDocument (Server "http://localhost:9200") "twitter"
> "tweet" exampleTweet "1"
>   print "test"
>   return ()
> el
> queryTweet :: IO (Either String Tweet)
> queryTweet = do
>   let queryFilter = BoolFilter (MustMatch (Term "user" "bitemyapp") False)
>                     <||> IdentityFilter
>   let search = Search Nothing (Just queryFilter)
>   reply <- searchByIndex testServer "twitter" search
>   let result = eitherDecode (responseBody reply) :: Either String
> (SearchResult Tweet)
>   let myTweet = fmap (hitSource . head . hits . searchHits) result
>   return myTweet
>
> main :: IO ()
> main = do
>   _ <- insertData
>   myTweet <- queryTweet
>   print myTweet
>
> further up the call chain, the http call is getting dispatched with
> http-conduit's gear, the result returned with the expression:
>
> withManager $ httpLbs req
>
> Included this in case it affects the semantics.
>
> Can anybody help? This has stumped me for a couple hours and I couldn't
> get anything clueful on IRC.
>
> Thanks to any that help.
>
> --- Chris
>
>
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