Copyright | This file is part of the package byline. It is subject to the license terms in the LICENSE file found in the top-level directory of this distribution and at: https://github.com/pjones/byline No part of this package including this file may be copied modified propagated or distributed except according to the terms contained in the LICENSE file. |
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License | BSD-2-Clause |

Safe Haskell | None |

Language | Haskell2010 |

## Synopsis

- data Menu a
- menu :: ToStylizedText a => NonEmpty a -> Menu a
- menuBanner :: ToStylizedText b => b -> Menu a -> Menu a
- menuPrefix :: (Int -> Stylized Text) -> Menu a -> Menu a
- menuSuffix :: Stylized Text -> Menu a -> Menu a
- type FromChoice a = Menu a -> Map Text a -> Text -> Choice a
- menuFromChoiceFunc :: FromChoice a -> Menu a -> Menu a
- askWithMenu :: (MonadByline m, ToStylizedText a, ToStylizedText b) => Menu a -> b -> m (Choice a)
- askWithMenuRepeatedly :: (MonadByline m, ToStylizedText a, ToStylizedText b, ToStylizedText e) => Menu a -> b -> e -> m a
- data Choice a
- module Byline

# Menus with Tab Completion

Menus are used to provide the user with a choice of acceptable values. Each choice is labeled to make it easier for a user to select it, or the user may enter text that does not correspond to any of the menus items.

For an example see the `menu.hs`

file in the `examples`

directory.

# Building a Menu

Opaque type representing a menu containing items of type `a`

.

*Since: 1.0.0.0*

## Instances

Foldable Menu Source # | |

Defined in Byline.Menu fold :: Monoid m => Menu m -> m # foldMap :: Monoid m => (a -> m) -> Menu a -> m # foldr :: (a -> b -> b) -> b -> Menu a -> b # foldr' :: (a -> b -> b) -> b -> Menu a -> b # foldl :: (b -> a -> b) -> b -> Menu a -> b # foldl' :: (b -> a -> b) -> b -> Menu a -> b # foldr1 :: (a -> a -> a) -> Menu a -> a # foldl1 :: (a -> a -> a) -> Menu a -> a # elem :: Eq a => a -> Menu a -> Bool # maximum :: Ord a => Menu a -> a # |

menu :: ToStylizedText a => NonEmpty a -> Menu a Source #

Create a `Menu`

by giving a list of menu items and a function
that can convert those items into stylized text.

*Since: 1.0.0.0*

menuBanner :: ToStylizedText b => b -> Menu a -> Menu a Source #

Change the banner of a menu. The banner is printed just before the menu items are displayed.

*Since: 1.0.0.0*

menuPrefix :: (Int -> Stylized Text) -> Menu a -> Menu a Source #

Change the prefix function. The prefix function should generate unique, stylized text that the user can use to select a menu item. The default prefix function numbers the menu items starting with 1.

*Since: 1.0.0.0*

menuSuffix :: Stylized Text -> Menu a -> Menu a Source #

Change the menu item suffix. It is displayed directly after the menu item prefix and just before the menu item itself.

Default: `") "`

*Since: 1.0.0.0*

type FromChoice a = Menu a -> Map Text a -> Text -> Choice a Source #

A function that is given the input from a user while working in a
menu and should translate that into a `Choice`

.

The `Map`

contains the menu item indexes/prefixes (numbers or
letters) and the items themselves.

The default `FromChoice`

function allows the user to select a menu
item by typing its index or part of its textual representation. As
long as input from the user is a unique prefix of one of the menu
items then that item will be returned.

*Since: 1.0.0.0*

menuFromChoiceFunc :: FromChoice a -> Menu a -> Menu a Source #

Change the `FromChoice`

function. The function should
compare the user's input to the menu items and their assigned
prefix values and return a `Choice`

.

*Since: 1.0.0.0*

# Prompting with a Menu

:: (MonadByline m, ToStylizedText a, ToStylizedText b) | |

=> Menu a | The |

-> b | The prompt. |

-> m (Choice a) | The |

Ask the user to choose an item from a menu. The menu will only
be shown once and the user's choice will be returned in a `Choice`

value.

If you want to force the user to only choose from the displayed
menu items you should use `askWithMenuRepeatedly`

instead.

*Since: 1.0.0.0*

askWithMenuRepeatedly Source #

:: (MonadByline m, ToStylizedText a, ToStylizedText b, ToStylizedText e) | |

=> Menu a | The |

-> b | The prompt. |

-> e | Error message when the user tried to select a non-menu item. |

-> m a | The |

Like `askWithMenu`

except that arbitrary input is not allowed.
If the user doesn't correctly select a menu item then the menu will
be repeated and an error message will be displayed.

*Since: 1.0.0.0*

A type representing the choice made by a user while working with a menu.

*Since: 1.0.0.0*

## Instances

Functor Choice Source # | |

Foldable Choice Source # | |

Defined in Byline.Menu fold :: Monoid m => Choice m -> m # foldMap :: Monoid m => (a -> m) -> Choice a -> m # foldr :: (a -> b -> b) -> b -> Choice a -> b # foldr' :: (a -> b -> b) -> b -> Choice a -> b # foldl :: (b -> a -> b) -> b -> Choice a -> b # foldl' :: (b -> a -> b) -> b -> Choice a -> b # foldr1 :: (a -> a -> a) -> Choice a -> a # foldl1 :: (a -> a -> a) -> Choice a -> a # elem :: Eq a => a -> Choice a -> Bool # maximum :: Ord a => Choice a -> a # minimum :: Ord a => Choice a -> a # | |

Traversable Choice Source # | |

Eq a => Eq (Choice a) Source # | |

Show a => Show (Choice a) Source # | |

# Re-exports

module Byline