Portability	portable
Stability	experimental
Maintainer	Bryan O'Sullivan <bos@serpentine.com>
Safe Haskell	None

Data.Configurator.Types

Contents

Exceptions
Notification of configuration changes

Description

Types for working with configuration files.

Synopsis

Documentation

data AutoConfig Source

Directions for automatically reloading Config data.

Constructors

AutoConfig

Fields

interval :: Int

Interval (in seconds) at which to check for updates to config files. The smallest allowed interval is one second.

onError :: SomeException -> IO ()

Action invoked when an attempt to reload a Config or notify a ChangeHandler causes an exception to be thrown.

If this action rethrows its exception or throws a new exception, the modification checking thread will be killed. You may want your application to treat that as a fatal error, as its configuration may no longer be consistent.

Instances

Show AutoConfig
Typeable AutoConfig

data Config Source

Configuration data.

type Name = Text Source

The name of a Config value.

data Value Source

A value in a Config.

Constructors

Bool Bool	A Boolean. Represented in a configuration file as `on` or `off`, `true` or `false` (case sensitive).
String Text	A Unicode string. Represented in a configuration file as text surrounded by double quotes. Escape sequences: `\n` - newline `\r` - carriage return `\t` - horizontal tab `\\` - backslash `\"` - quotes `\u`xxxx - Unicode character, encoded as four hexadecimal digits `\u`xxxx`\u`xxxx - Unicode character (as two UTF-16 surrogates)
Number Rational	Integer.
List [Value]	Heterogeneous list. Represented in a configuration file as an opening square bracket "`[`", followed by a comma-separated series of values, ending with a closing square bracket "`]`".

Instances

Eq Value
Data Value
Show Value
Typeable Value
Configured Value

class Configured a whereSource

This class represents types that can be automatically and safely converted from a Value to a destination type. If conversion fails because the types are not compatible, Nothing is returned.

For an example of compatibility, a Value of Bool True cannot be converted to an Int.

Methods

convert :: Value -> Maybe aSource

Instances

Configured Bool
Configured Double
Configured Float
Configured Int
Configured Int8
Configured Int16
Configured Int32
Configured Int64
Configured Integer
Configured Word
Configured Word8
Configured Word16
Configured Word32
Configured Word64
Configured ByteString
Configured ByteString
Configured Text
Configured CFloat
Configured CDouble
Configured Text
Configured Value
Configured [Char]
Integral a => Configured (Ratio a)
HasResolution a => Configured (Fixed a)
RealFloat a => Configured (Complex a)
(Configured a, Configured b) => Configured (a, b)
(Configured a, Configured b, Configured c) => Configured (a, b, c)
(Configured a, Configured b, Configured c, Configured d) => Configured (a, b, c, d)

data Worth a Source

Constructors

Required
Fields worth :: a
Optional
Fields worth :: a

Instances

Functor Worth
Typeable1 Worth
Eq a => Eq (Worth a)
Show a => Show (Worth a)
IsString (Worth FilePath)
Hashable a => Hashable (Worth a)

Exceptions

data ConfigError Source

An error occurred while processing a configuration file.

Constructors

ParseError FilePath String

Instances

Show ConfigError
Typeable ConfigError
Exception ConfigError

data KeyError Source

An error occurred while lookup up the given Name.

Constructors

KeyError Name

Instances

Show KeyError
Typeable KeyError
Exception KeyError

Notification of configuration changes

data Pattern Source

A pattern specifying the name of a property that has changed.

This type is an instance of the IsString class. If you use the OverloadedStrings language extension and want to write a prefix-matching pattern as a literal string, do so by suffixing it with ".*", for example as follows:

 "foo.*"

If a pattern written as a literal string does not end with ".*", it is assumed to be exact.

Instances

Eq Pattern
Data Pattern
Show Pattern
Typeable Pattern
IsString Pattern
Hashable Pattern

type ChangeHandler Source

Arguments

= Name	Name of the changed property.
-> Maybe Value	Its new value, or `Nothing` if it has vanished.
-> IO ()

An action to be invoked if a configuration property is changed.

If this action is invoked and throws an exception, the onError function will be called.