Config.FromConfig

This module provides tools for producing structured configuration information out of configuration values.

Configuration parsing

data ConfigParser a

Configuration parser tracking current location and for propagating error information.

Instances

Monad ConfigParser

Methods

(>>=) :: ConfigParser a -> (a -> ConfigParser b) -> ConfigParser b

(>>) :: ConfigParser a -> ConfigParser b -> ConfigParser b

return :: a -> ConfigParser a

fail :: String -> ConfigParser a

Functor ConfigParser

Methods

fmap :: (a -> b) -> ConfigParser a -> ConfigParser b

(<$) :: a -> ConfigParser b -> ConfigParser a

Applicative ConfigParser

Methods

pure :: a -> ConfigParser a

(<*>) :: ConfigParser (a -> b) -> ConfigParser a -> ConfigParser b

(*>) :: ConfigParser a -> ConfigParser b -> ConfigParser b

(<*) :: ConfigParser a -> ConfigParser b -> ConfigParser a

decodeConfig :: FromConfig a => Value -> Either Text a

Parse a Value according to the method in the FromConfig

runConfigParser :: ConfigParser a -> Either Text a

Run a top-level parser to either get the parsed value or an error message.

failure

Arguments

:: Text

error message

-> ConfigParser a

A parser that always fails with the given error message.

extendLoc :: Text -> ConfigParser a -> ConfigParser a

Embed a parser into an extended location. This is used when parsing inside a section.

class FromConfig a where

Class for types that have a well-known way to parse them.

Minimal complete definition

parseConfig

Methods

parseConfig :: Value -> ConfigParser a

Parse a value

Instances

FromConfig Integer

Matches Number values ignoring the base

Methods

parseConfig :: Value -> ConfigParser Integer

FromConfig Text

Matches Text values.

Methods

parseConfig :: Value -> ConfigParser Text

FromConfig Atom

Matches Atom values

Methods

parseConfig :: Value -> ConfigParser Atom

FromConfig a => FromConfig [a]

Matches List values, extends the error location with a zero-based index

Methods

parseConfig :: Value -> ConfigParser [a]

Integral a => FromConfig (Ratio a)

Matches Number values ignoring the base

Methods

parseConfig :: Value -> ConfigParser (Ratio a)

Parser wrappers

parseList :: (Value -> ConfigParser a) -> Value -> ConfigParser [a]

Section parsing

data SectionParser a

Parser for consuming key-value pairs of sections.

Instances

Monad SectionParser

Methods

(>>=) :: SectionParser a -> (a -> SectionParser b) -> SectionParser b

(>>) :: SectionParser a -> SectionParser b -> SectionParser b

return :: a -> SectionParser a

fail :: String -> SectionParser a

Functor SectionParser

Methods

fmap :: (a -> b) -> SectionParser a -> SectionParser b

(<$) :: a -> SectionParser b -> SectionParser a

Applicative SectionParser

Methods

pure :: a -> SectionParser a

(<*>) :: SectionParser (a -> b) -> SectionParser a -> SectionParser b

(*>) :: SectionParser a -> SectionParser b -> SectionParser b

(<*) :: SectionParser a -> SectionParser b -> SectionParser a

parseSections :: SectionParser a -> Value -> ConfigParser a

Run a SectionParser given particular Value. This will only succeed when the value is a Sections and the section parser consumes all of the sections from that value.

sectionReq :: FromConfig a => Text -> SectionParser a

Parse the value at the given section or fail.

sectionReqWith :: (Value -> ConfigParser a) -> Text -> SectionParser a

Parse the value at the given section or fail.

sectionOpt :: FromConfig a => Text -> SectionParser (Maybe a)

sectionOpt = sectionOptWith parseConfig

sectionOptWith :: (Value -> ConfigParser a) -> Text -> SectionParser (Maybe a)

Parses the value stored at the given section with the given parser. Nothing is returned if the section is missing. Just is returned if the parse succeeds Error is raised if the section is present but the parse fails

liftConfigParser :: ConfigParser a -> SectionParser a

Lift a ConfigParser into a SectionParser leaving the current section information unmodified.

parseSectionsWith :: (a -> Text -> Value -> ConfigParser a) -> a -> Value -> ConfigParser a