Safe Haskell	Safe-Inferred
Language	Haskell2010

Database.InfluxDB.JSON

Contents

Result parsers
- Decoder settings
Getting fields and tags
Common JSON object parsers
- Utility functions

Synopsis

parseResultsWith :: (Maybe Text -> HashMap Text Text -> Vector Text -> Array -> Parser a) -> Value -> Parser (Vector a)
parseResultsWithDecoder :: Decoder -> (Maybe Text -> HashMap Text Text -> Vector Text -> Array -> Parser a) -> Value -> Parser (Vector a)
newtype Decoder = Decoder (forall a. SomeDecoder a)
data SomeDecoder a = forall b.SomeDecoder {
- decodeEach :: Parser a -> Parser b
- decodeFold :: Parser (Vector b) -> Parser (Vector a)
}
strictDecoder :: Decoder
lenientDecoder :: Decoder
getField :: MonadFail m => Text -> Vector Text -> Vector Value -> m Value
getTag :: MonadFail m => Text -> HashMap Text Value -> m Value
parseJSON :: FromJSON a => Value -> Parser a
parseUTCTime :: Precision ty -> Value -> Parser UTCTime
parsePOSIXTime :: Precision ty -> Value -> Parser POSIXTime
parseRFC3339 :: ParseTime time => Value -> Parser time
parseResultsObject :: Value -> Parser (Vector Value)
parseSeriesObject :: Value -> Parser (Vector Value)
parseSeriesBody :: Value -> Parser (Maybe Text, HashMap Text Text, Vector Text, Array)
parseErrorObject :: Value -> Parser String

Result parsers

parseResultsWith Source #

Arguments

:: (Maybe Text -> HashMap Text Text -> Vector Text -> Array -> Parser a)

A parser that parses a measurement. A measurement consists of

an optional name of the series
a map of tags
an array of field keys
an array of field values

-> Value

JSON response

-> Parser (Vector a)

Parse a JSON response with the strictDecoder.

parseResultsWithDecoder Source #

Arguments

:: Decoder
-> (Maybe Text -> HashMap Text Text -> Vector Text -> Array -> Parser a)	A parser that parses a measurement. A measurement consists of an optional name of the series a map of tags an array of field keys an array of field values
-> Value	JSON response
-> Parser (Vector a)

Parse a JSON response with the specified decoder settings.

Decoder settings

newtype Decoder Source #

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.

Constructors

Decoder (forall a. SomeDecoder a)

data SomeDecoder a Source #

SomeDecoder a represents how to decode a JSON response given a row parser of type Parser a.

Constructors

forall b. SomeDecoder
Fields decodeEach :: Parser a -> Parser b How to decode each row. For example `optional` can be used to turn parse failrues into `Nothing`s. decodeFold :: Parser (Vector b) -> 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.

strictDecoder :: Decoder Source #

A decoder that fails immediately if there's any parse failure.

strictDecoder is defined as follows:

strictDecoder :: Decoder
strictDecoder = Decoder $ SomeDecoder
 { decodeEach = id
 , decodeFold = id
 }

lenientDecoder :: Decoder Source #

A decoder that ignores parse failures and returns only successful results.

Getting fields and tags

getField Source #

Arguments

:: MonadFail m
=> Text	Column name
-> Vector Text	Columns
-> Vector Value	Field values
-> m Value

Get a field value from a column name

getTag Source #

Arguments

:: MonadFail m
=> Text	Tag name
-> HashMap Text Value	Tags
-> m Value

Get a tag value from a tag name

Common JSON object parsers

parseJSON :: FromJSON a => Value -> Parser a #

parseUTCTime :: Precision ty -> Value -> Parser UTCTime Source #

Parse either a POSIX timestamp or RFC3339 formatted timestamp as UTCTime.

parsePOSIXTime :: Precision ty -> Value -> Parser POSIXTime Source #

Parse either a POSIX timestamp or RFC3339 formatted timestamp as POSIXTime.

parseRFC3339 :: ParseTime time => Value -> Parser time Source #

Parse a RFC3339-formatted timestamp.

Note that this parser is slow as it converts a Text input to a String before parsing.

Utility functions

parseResultsObject :: Value -> Parser (Vector Value) Source #

Parse a result response.

parseSeriesObject :: Value -> Parser (Vector Value) Source #

Parse a series response.

parseSeriesBody :: Value -> Parser (Maybe Text, HashMap Text Text, Vector Text, Array) Source #

Parse the common JSON structure used in query responses.

parseErrorObject :: Value -> Parser String Source #

Parse the common JSON structure used in failure response. >>> A.parse parseErrorObject $ fromJust $ decode "{ "error": "custom error" }" Success "custom error" >>> A.parse parseErrorObject $ fromJust $ decode "{ "message": "custom error" }" Success "custom error"