Merge branch 'release/v1.8.0'

.travis.yml

@@ -8,15 +8,15 @@
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
-# version: 0.10.1
+# version: 0.10.2
 #
 version: ~> 1.0
 language: c
 os: linux
 dist: xenial
 env:
   global:
-    - INFLUXDB_VERSION=1.7.10
+    - INFLUXDB_VERSION=1.8.0
 git:
   # whether to recursively clone submodules
   submodules: false
@@ -171,5 +171,5 @@ script:
   - rm -f cabal.project.local
   - ${CABAL} v2-build $WITHCOMPILER --disable-tests --disable-benchmarks all
 
-# REGENDATA ("0.10.1",["influxdb.cabal","--ghc-head","--travis-patches=.travis/influxdb.patch"])
+# REGENDATA ("0.10.2",["influxdb.cabal","--ghc-head","--travis-patches=.travis/influxdb.patch"])
 # EOF

.travis/influxdb.patch

@@ -8,7 +8,7 @@ index c9bac24..2fcb7ab 100644
  dist: xenial
 +env:
 +  global:
-+    - INFLUXDB_VERSION=1.7.10
++    - INFLUXDB_VERSION=1.8.0
  git:
    # whether to recursively clone submodules
    submodules: false

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Revision history for influxdb
 
+## v1.8.0 - 2020-06-19
+
+This release reworked the `QueryResuls` type class. There are some breaking changes:
+
+* `parseResults` has been deprecated. `QueryResults` has now `parseMeasurement` method.
+* `Decoder` has been monomorphized so that it can be used with lens. The original `Decoder` type has been renamed to `SomeDecoder`.
+* `QueryParams` has now `decoder` field.
+* `parseResults` and `parseResultsWith` had been using `lenientDecoder` and it caused some unintuitive behavior ([#64](https://github.com/maoe/influxdb-haskell/issues/64), [#66](https://github.com/maoe/influxdb-haskell/issues/66)). Now they use `strictDecoder` instead.
+* `parseErrorObject` now doesn't fail. It returns the error message of a response.
+* `parseQueryField` which has been deprecated is now deleted.
+* `QueryResults` instance for `ShowSeries` was broken. This is fixed.
+* The constructor of `Decoder`, `parseResultsWith`, and `parseResultsWithDecoder` have been hidden from the top-level module. They're still available from `Database.InfluxDB.JSON`.
+
+See [#68](https://github.com/maoe/influxdb-haskell/pull/68/files) for how to migrate your code from v1.7.x to v1.8.x.
+
 ## v1.7.1.6 - 2020-06-03
 
 * Relax upper version bound for doctest

README.md

@@ -6,7 +6,7 @@
 [![Hackage CI](https://matrix.hackage.haskell.org/api/v2/packages/influxdb/badge)](https://matrix.hackage.haskell.org/package/influxdb)
 [![Gitter](https://badges.gitter.im/maoe/influxdb-haskell.svg)](https://gitter.im/maoe/influxdb-haskell?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
-Currently this library is tested against InfluxDB 1.7.
+Currently this library is tested against InfluxDB 1.8.
 
 ## Getting started
 

examples/random-points.hs

@@ -2,7 +2,6 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE ViewPatterns #-}
 import Data.Foldable
@@ -76,7 +75,7 @@ data Row = Row
   } deriving Show
 
 instance QueryResults Row where
-  parseResults prec = parseResultsWith $ \_ _ columns fields -> do
+  parseMeasurement prec _ _ columns fields = do
     rowTime <- getField "time" columns fields >>= parsePOSIXTime prec
     String name <- getField "value" columns fields
     rowValue <- case name of

hie.yaml

@@ -0,0 +1,16 @@
+cradle:
+  cabal:
+    - path: "./src"
+      component: "lib:influxdb"
+
+    - path: "./tests"
+      component: "influxdb:test:doctests"
+
+    - path: "./tests"
+      component: "influxdb:test:regressions"
+
+    - path: "./examples/random-points.hs"
+      component: "influxdb:exe:influx-random-points"
+
+    - path: "./examples/write-udp.hs"
+      component: "influxdb:exe:influx-write-udp"

influxdb.cabal

@@ -1,6 +1,6 @@
 cabal-version: 1.24
 name: influxdb
-version: 1.7.1.6
+version: 1.8.0
 synopsis: Haskell client library for InfluxDB
 description:
   @influxdb@ is an InfluxDB client library for Haskell.
@@ -115,10 +115,12 @@ test-suite regressions
       base
     , containers
     , influxdb
+    , lens
     , tasty
     , tasty-hunit
     , time
     , raw-strings-qq >= 1.1 && < 1.2
+    , vector
   ghc-options: -Wall -threaded
   hs-source-dirs: tests
   default-language: Haskell2010

src/Database/InfluxDB.hs

@@ -45,20 +45,18 @@ module Database.InfluxDB
   , QueryParams
   , queryParams
   , authentication
+  , decoder
 
   -- ** Parsing results
   , QueryResults(..)
-  , parseResultsWith
-  , parseResultsWithDecoder
-  , Decoder(..)
+  , Decoder
   , lenientDecoder
   , strictDecoder
   , getField
   , getTag
   , parseJSON
   , parseUTCTime
   , parsePOSIXTime
-  , parseQueryField
 
   -- *** Re-exports from tagged
   , Tagged(..)
@@ -200,7 +198,7 @@ data CPUUsage = CPUUsage
   , cpuIdle, cpuSystem, cpuUser :: Double
   } deriving Show
 instance QueryResults CPUUsage where
-  parseResults prec = parseResultsWithDecoder strictDecoder $ \_ _ columns fields -> do
+  parseMeasurement prec _name _tags columns fields = do
     time <- getField "time" columns fields >>= parseUTCTime prec
     cpuIdle <- getField "idle" columns fields >>= parseJSON
     cpuSystem <- getField "system" columns fields >>= parseJSON

src/Database/InfluxDB/JSON.hs

@@ -3,6 +3,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ViewPatterns #-}
 module Database.InfluxDB.JSON
@@ -12,6 +13,7 @@ module Database.InfluxDB.JSON
 
   -- ** Decoder settings
   , Decoder(..)
+  , SomeDecoder(..)
   , strictDecoder
   , lenientDecoder
 
@@ -24,7 +26,6 @@ module Database.InfluxDB.JSON
   , parseUTCTime
   , parsePOSIXTime
   , parseRFC3339
-  , parseQueryField
   -- ** Utility functions
   , parseResultsObject
   , parseSeriesObject
@@ -34,8 +35,10 @@ module Database.InfluxDB.JSON
 import Control.Applicative
 import Control.Exception
 import Control.Monad
-import qualified Control.Monad.Fail as Fail
+import Data.Foldable
 import Data.Maybe
+import Prelude
+import qualified Control.Monad.Fail as Fail
 
 import Data.Aeson
 import Data.HashMap.Strict (HashMap)
@@ -52,69 +55,100 @@ import qualified Data.Vector as V
 
 import Database.InfluxDB.Types
 
--- | Parse a JSON response with the 'lenientDecoder'. This can be useful to
--- implement the 'Database.InfluxDB.Query.parseResults' method.
+-- | Parse a JSON response with the 'strictDecoder'.
 parseResultsWith
   :: (Maybe Text -> HashMap Text Text -> Vector Text -> Array -> A.Parser a)
-  -- ^ A parser that takes
+  -- ^ A parser that parses a measurement. A measurement consists of
   --
   -- 1. an optional name of the series
   -- 2. a map of tags
-  -- 3. an array of field names
-  -- 4. an array of values
-  --
-  -- to construct a value.
-  -> Value
+  -- 3. an array of field keys
+  -- 4. an array of field values
+  -> Value -- ^ JSON response
   -> A.Parser (Vector a)
-parseResultsWith = parseResultsWithDecoder lenientDecoder
+parseResultsWith = parseResultsWithDecoder strictDecoder
 
 -- | Parse a JSON response with the specified decoder settings.
 parseResultsWithDecoder
-  :: Decoder a
+  :: Decoder
   -> (Maybe Text -> HashMap Text Text -> Vector Text -> Array -> A.Parser a)
-  -- ^ A parser that takes
+  -- ^ A parser that parses a measurement. A measurement consists of
   --
   -- 1. an optional name of the series
   -- 2. a map of tags
-  -- 3. an array of field names
-  -- 4. an array of values
-  --
-  -- to construct a value.
-  -> Value
+  -- 3. an array of field keys
+  -- 4. an array of field values
+  -> Value -- ^ JSON response
   -> A.Parser (Vector a)
-parseResultsWithDecoder Decoder {..} row val0 = success
+parseResultsWithDecoder (Decoder SomeDecoder {..}) row val0 = do
+  r <- foldr1 (<|>)
+    [ Left <$> parseErrorObject val0
+    , Right <$> success
+    ]
+  case r of
+    Left err -> fail err
+    Right vec -> return vec
   where
     success = do
       results <- parseResultsObject val0
 
-      (join -> series) <- V.forM results $ \val ->
-        parseSeriesObject val <|> parseErrorObject val
+      (join -> series) <- V.forM results $ \val -> do
+        r <- foldr1 (<|>)
+          [ Left <$> parseErrorObject val
+          , Right <$> parseSeriesObject val
+          ]
+        case r of
+          Left err -> fail err
+          Right vec -> return vec
       values <- V.forM series $ \val -> do
         (name, tags, columns, values) <- parseSeriesBody val
         decodeFold $ V.forM values $ A.withArray "values" $ \fields -> do
           assert (V.length columns == V.length fields) $ return ()
           decodeEach $ row name tags columns fields
       return $! join values
 
--- | Decoder settings
-data Decoder a = forall b. Decoder
+-- | A decoder to use when parsing a JSON response.
+--
+-- Use 'strictDecoder' if you want to fail the entire decoding process if
+-- there's any failure. Use 'lenientDecoder' if you want the decoding process
+-- to collect only successful results.
+newtype Decoder = Decoder (forall a. SomeDecoder a)
+
+-- | @'SomeDecoder' a@ represents how to decode a JSON response given a row
+-- parser of type @'A.Parser' a@.
+data SomeDecoder a = forall b. SomeDecoder
   { decodeEach :: A.Parser a -> A.Parser b
-  -- ^ How to decode each row. For example 'optional' can be used to turn parse
+  -- ^ How to decode each row.
+  --
+  -- For example 'optional' can be used to turn parse
   -- failrues into 'Nothing's.
   , decodeFold :: A.Parser (Vector b) -> A.Parser (Vector a)
   -- ^ How to aggregate rows into the resulting vector.
+  --
+  -- For example when @b ~ 'Maybe' a@, one way to aggregate the values is to
+  -- return only 'Just's.
   }
 
 -- | A decoder that fails immediately if there's any parse failure.
-strictDecoder :: Decoder a
-strictDecoder = Decoder
+--
+-- 'strictDecoder' is defined as follows:
+--
+-- @
+-- strictDecoder :: Decoder
+-- strictDecoder = Decoder $ SomeDecoder
+--  { decodeEach = id
+--  , decodeFold = id
+--  }
+-- @
+strictDecoder :: Decoder
+strictDecoder = Decoder $ SomeDecoder
   { decodeEach = id
   , decodeFold = id
   }
 
 -- | A decoder that ignores parse failures and returns only successful results.
-lenientDecoder :: Decoder a
-lenientDecoder = Decoder
+lenientDecoder :: Decoder
+lenientDecoder = Decoder $ SomeDecoder
   { decodeEach = optional
   , decodeFold = \p -> do
     bs <- p
@@ -166,10 +200,8 @@ parseSeriesBody = A.withObject "series" $ \obj -> do
   return (name, tags, columns, values)
 
 -- | Parse the common JSON structure used in failure response.
-parseErrorObject :: A.Value -> A.Parser a
-parseErrorObject = A.withObject "error" $ \obj -> do
-  message <- obj .: "error"
-  fail $ T.unpack message
+parseErrorObject :: A.Value -> A.Parser String
+parseErrorObject = A.withObject "error" $ \obj -> obj .: "error"
 
 -- | Parse either a POSIX timestamp or RFC3339 formatted timestamp as 'UTCTime'.
 parseUTCTime :: Precision ty -> A.Value -> A.Parser UTCTime
@@ -207,20 +239,3 @@ parseRFC3339 val = A.withText err
     fmt, err :: String
     fmt = "%FT%X%QZ"
     err = "RFC3339-formatted timestamp"
-
--- | Parse a 'QueryField'.
-parseQueryField :: A.Value -> A.Parser QueryField
-parseQueryField val = case val of
-  A.Number sci ->
-    return $! either FieldFloat FieldInt $ Sci.floatingOrInteger sci
-  A.String txt ->
-    return $! FieldString txt
-  A.Bool b ->
-    return $! FieldBool b
-  A.Null ->
-    return FieldNull
-  _ -> fail $ "parseQueryField: expected a flat data structure, but got "
-    ++ show val
-{-# DEPRECATED parseQueryField
-  "This function parses numbers in a misleading way. Use 'parseJSON' instead."
-  #-}