Copyright	(c) Matthew Peddie 2014
License	BSD3
Maintainer	mpeddie@gmail.com
Stability	experimental
Portability	GHC
Safe Haskell	None
Language	Haskell2010

Language.Libconfig.Encode

Contents

Encoding libconfig native data
Encoding errors
Helpers

Description

Converting from Language.Libconfig.Types structures to native libconfig Configurations.

Synopsis

Documentation

To run these usage examples, you must tell GHC it's allowed to parse string literals as Text values:

>>> :set -XOverloadedStrings

We also pre-define the test Group to be the example from the libconfig manual.

>>> let Just [version, application, window, title, size, w, h, pos, x, y, list, books, author, price, qty, misc, pi, columns, bigint, bitmask] = mapM textToName ["version", "application", "window", "title", "size", "w", "h", "pos", "x", "y", "list", "books", "author", "price", "qty", "misc", "pi", "columns", "bigint", "bitmask"]
>>> let test = [version := Scalar (String "1.0"),application := Group [window := Group [title := Scalar (String "My Application"),size := Group [w := Scalar (Integer 640),h := Scalar (Integer 480)],pos := Group [x := Scalar (Integer 350),y := Scalar (Integer 250)]],list := List [List [Scalar (String "abc"),Scalar (Integer 123),Scalar (Boolean True)],Scalar (Float 1.234),List []],books := List [Group [title := Scalar (String "Treasure Island"),author := Scalar (String "Robert Louis Stevenson"),price := Scalar (Float 29.95),qty := Scalar (Integer 5)],Group [title := Scalar (String "Snow Crash"),author := Scalar (String "Neal Stephenson"),price := Scalar (Float 9.99),qty := Scalar (Integer 8)]],misc := Group [pi := Scalar (Float 3.141592654),bigint := Scalar (Integer64 9223372036854775807),columns := Array [String "Last Name",String "First Name",String "MI"],bitmask := Scalar (Hex 8131)]]]

Encoding libconfig native data

encode :: Group -> IO (Either EncodeError Configuration) Source

Convert a top-level Group of Settings into a native Configuration. This allocates a new Configuration.

>>> Right conf <- encode test
>>> C.configWriteFile conf "/tmp/encode_output_test.conf"
Just ()

>>> Just newconf <- C.configNew "/tmp/encode_output_test.conf"

encodeAt :: Configuration -> Group -> IO (Either EncodeError ()) Source

Encode a top-level Group of Settings and write them to the specified Configuration.

encodeValue :: Setting -> Value -> IO (Either EncodeError ()) Source

Set the value of the given Setting to the provided Value (recursively). If this Setting is of a collection type, any pre-existing children will be removed.

encodeTo :: Group -> String -> IO (Either EncodeError ()) Source

Convert a top-level Group of Settings into a native libconfig structure and output it to the specified file path.

>>> encodeTo test "/tmp/encode_output_test_2.conf"
Right ()

>>> Just newconf <- C.configNew "/tmp/encode_output_test_2.conf"

Encoding errors

data EncodeError Source

Any of these problems can occur while encoding a libconfig Configuration.

Constructors

EncoderRoot	No root setting was found (possibly this configuration is invalid?)
TypeMismatch
Fields encodeErrSetting :: Text The Haskell structure contained invalid libconfig types for this setting.
FileOutput
Fields encodeErrFilename :: Text Failed to open this file
AddSetting
Fields encodeErrParent :: Text Failed to create a new `Setting` encodeErrValue :: Value This was the value we were making a spot for
RemoveOldValue
Fields encodeErrSetting :: Text The Haskell structure contained invalid libconfig types for this setting.
SetValue
Fields encodeErrSetting :: Text The Haskell structure contained invalid libconfig types for this setting. encodeErrValue :: Value This was the value we were making a spot for
SetIndex
Fields encodeErrParent :: Text Failed to create a new `Setting` encodeErrIndex :: Int This is the index of the element encodeErrValue :: Value This was the value we were making a spot for

Instances

Eq EncodeError
Data EncodeError
Ord EncodeError
Read EncodeError
Show EncodeError
Generic EncodeError
NFData EncodeError
Typeable * EncodeError
type Rep EncodeError

Helpers

valueType :: Value -> ConfigType Source

Compute the ConfigType of a Value

>>> valueType (Scalar (String "butts"))
StringType

>>> valueType (Array [String "butts"])
ArrayType

scalarType :: Scalar -> ConfigType Source

Compute the ConfigType of a Scalar

>>> scalarType (String "butts")
StringType

>>> scalarType (Boolean False)
BoolType