Env.Internal.Parser

Documentation

newtype Parser e a

An environment parser

Constructors

Parser

Fields

• unParser :: Alt (VarF e) a

Instances

Functor (Parser e)

Defined in Env.Internal.Parser

Methods

fmap :: (a -> b) -> Parser e a -> Parser e b

(<$) :: a -> Parser e b -> Parser e a

Applicative (Parser e)

Defined in Env.Internal.Parser

Methods

pure :: a -> Parser e a

(<*>) :: Parser e (a -> b) -> Parser e a -> Parser e b

liftA2 :: (a -> b -> c) -> Parser e a -> Parser e b -> Parser e c

(*>) :: Parser e a -> Parser e b -> Parser e b

(<*) :: Parser e a -> Parser e b -> Parser e a

Alternative (Parser e)

Defined in Env.Internal.Parser

Methods

empty :: Parser e a

(<|>) :: Parser e a -> Parser e a -> Parser e a

some :: Parser e a -> Parser e [a]

many :: Parser e a -> Parser e [a]

data VarF e a

Constructors

VarF

Fields

• varfName :: String
• varfReader :: String -> Map String String -> Either e a
• varfHelp :: Maybe String
• varfDef :: Maybe a
• varfHelpDef :: Maybe String
• varfKeep :: Bool

Instances

Functor (VarF e)

Defined in Env.Internal.Parser

Methods

fmap :: (a -> b) -> VarF e a -> VarF e b

(<$) :: a -> VarF e b -> VarF e a

parsePure :: Parser e a -> [(String, String)] -> Either [(String, e)] a

Try to parse a pure environment

eachUnsetVar :: Applicative m => Parser e a -> (String -> m b) -> m ()

newtype Mod t a

This represents a modification of the properties of a particular Parser. Combine them using the Monoid instance.

Constructors

Mod (t a -> t a)

Instances

Semigroup (Mod t a)

Defined in Env.Internal.Parser

Methods

(<>) :: Mod t a -> Mod t a -> Mod t a

sconcat :: NonEmpty (Mod t a) -> Mod t a

stimes :: Integral b => b -> Mod t a -> Mod t a

Monoid (Mod t a)

Defined in Env.Internal.Parser

Methods

mempty :: Mod t a

mappend :: Mod t a -> Mod t a -> Mod t a

mconcat :: [Mod t a] -> Mod t a

prefixed :: String -> Parser e a -> Parser e a

The string to prepend to the name of every declared environment variable

var :: AsUnset e => Reader e a -> String -> Mod Var a -> Parser e a

Parse a particular variable from the environment

>>> var str "EDITOR" (def "vim" <> helpDef show)

data Var a

Environment variable metadata

Constructors

Var

Fields

• varHelp :: Maybe String
• varHelpDef :: Maybe (a -> String)
• varDef :: Maybe a
• varKeep :: Bool

Instances

HasKeep Var

Defined in Env.Internal.Parser

Methods

setKeep :: Var a -> Var a

HasHelp Var

Defined in Env.Internal.Parser

Methods

setHelp :: String -> Var a -> Var a

defaultVar :: Var a

type Reader e a = String -> Either e a

An environment variable's value parser. Use (<=<) and (>=>) to combine these

str :: IsString s => Reader e s

The trivial reader

nonempty :: (AsEmpty e, IsString s) => Reader e s

The reader that accepts only non-empty strings

splitOn :: Char -> Reader e [String]

The reader that splits a string into a list of strings consuming the separator.

auto :: (AsUnread e, Read a) => Reader e a

The reader that uses the Read instance of the type

def :: a -> Mod Var a

The default value of the variable

Note: specifying it means the parser won't ever fail.

helpDef :: (a -> String) -> Mod Var a

Show the default value of the variable in help.

showDef :: Show a => Mod Var a

Use the Show instance to show the default value of the variable in help.

flag

Arguments

:: a

default value

-> a

active value

-> String

-> Mod Flag a

-> Parser e a

A flag that takes the active value if the environment variable is set and non-empty and the default value otherwise

Note: this parser never fails.

switch :: String -> Mod Flag Bool -> Parser e Bool

A simple boolean flag

Note: this parser never fails.

data Flag a

Flag metadata

Instances

HasKeep Flag

Defined in Env.Internal.Parser

Methods

setKeep :: Flag a -> Flag a

HasHelp Flag

Defined in Env.Internal.Parser

Methods

setHelp :: String -> Flag a -> Flag a

class HasHelp t

A class of things that can have a help message attached to them

Minimal complete definition

setHelp

Instances

HasHelp Flag

Defined in Env.Internal.Parser

Methods

setHelp :: String -> Flag a -> Flag a

HasHelp Var

Defined in Env.Internal.Parser

Methods

setHelp :: String -> Var a -> Var a

help :: HasHelp t => String -> Mod t a

Attach help text to the variable

class HasKeep t

A class of things that can be still kept in an environment when the parsing has been completed.

Minimal complete definition

setKeep

Instances

HasKeep Flag

Defined in Env.Internal.Parser

Methods

setKeep :: Flag a -> Flag a

HasKeep Var

Defined in Env.Internal.Parser

Methods

setKeep :: Var a -> Var a

keep :: HasKeep t => Mod t a

Keep a variable.