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data HashMap k v

basic-prelude CorePrelude

A map from keys to values. A map cannot contain duplicate keys; each key can map to at most one value.
data IntMap a

basic-prelude CorePrelude

A map of integers to values a.
fmap :: Functor f => (a -> b) -> f a -> f b

basic-prelude CorePrelude

fmap is used to apply a function of type (a -> b) to a value of type f a, where f is a functor, to produce a value of type f b. Note that for any type constructor with more than one parameter (e.g., Either), only the last type parameter can be modified with fmap (e.g., b in `Either a b`). Some type constructors with two parameters or more have a Bifunctor instance that allows both the last and the penultimate parameters to be mapped over.
Examples
Convert from a Maybe Int to a Maybe String using show:
```
>>> fmap show Nothing
Nothing

>>> fmap show (Just 3)
Just "3"
```
Convert from an Either Int Int to an Either Int String using show:
```
>>> fmap show (Left 17)
Left 17

>>> fmap show (Right 17)
Right "17"
```
Double each element of a list:
```
>>> fmap (*2) [1,2,3]
[2,4,6]
```
Apply even to the second element of a pair:
```
>>> fmap even (2,2)
(2,True)
```
It may seem surprising that the function is only applied to the last element of the tuple compared to the list example above which applies it to every element in the list. To understand, remember that tuples are type constructors with multiple type parameters: a tuple of 3 elements (a,b,c) can also be written (,,) a b c and its Functor instance is defined for Functor ((,,) a b) (i.e., only the third parameter is free to be mapped over with fmap). It explains why fmap can be used with tuples containing values of different types as in the following example:
```
>>> fmap even ("hello", 1.0, 4)
("hello",1.0,True)
```
module Brick.AttrMap

This module provides types and functions for managing an attribute map which maps attribute names (AttrName) to attributes (Attr). Attribute maps work by mapping hierarchical attribute names to attributes and inheriting parent names' attributes when child names specify partial attributes. Hierarchical names are created with mappend:
```
let n = attrName "parent" <> attrName "child"
```
Attribute names are mapped to attributes, but some attributes may be partial (specify only a foreground or background color). When attribute name lookups occur, the attribute corresponding to a more specific name ('parent <> child' as above) is successively merged with the parent attribute (parent as above) all the way to the "root" of the attribute map, the map's default attribute. In this way, more specific attributes inherit what they don't specify from more general attributes in the same hierarchy. This allows more modularity and less repetition in specifying how elements of your user interface take on different attributes.
data AttrMap

brick Brick.AttrMap

An attribute map which maps AttrName values to Attr values.
applyAttrMappings :: [(AttrName, Attr)] -> AttrMap -> AttrMap

brick Brick.AttrMap

Insert a set of attribute mappings to an attribute map.
attrMap :: Attr -> [(AttrName, Attr)] -> AttrMap

brick Brick.AttrMap

Create an attribute map.
attrMapLookup :: AttrName -> AttrMap -> Attr

brick Brick.AttrMap

Look up the specified attribute name in the map. Map lookups proceed as follows. If the attribute map is forcing all lookups to a specific attribute, that attribute is returned along with its style settings. If the attribute name is empty, the map's default attribute is returned. If the attribute name is non-empty, every subsequence of names from the specified name are used to perform a lookup and the results are combined as in mergeWithDefault, with more specific results taking precedence over less specific ones. As attributes are merged, styles are also merged. If a more specific attribute name introduces a style (underline, say) and a less specific attribute name introduces an additional style (bold, say) then the final result will include both styles. For example:
```
attrMapLookup (attrName "foo" <> attrName "bar") (attrMap a []) == a
attrMapLookup (attrName "foo" <> attrName "bar") (attrMap (bg blue) [(attrName "foo" <> attrName "bar", fg red)]) == red `on` blue
attrMapLookup (attrName "foo" <> attrName "bar") (attrMap (bg blue) [(attrName "foo" <> attrName "bar", red on cyan)]) == red `on` cyan
attrMapLookup (attrName "foo" <> attrName "bar") (attrMap (bg blue) [(attrName "foo" <> attrName "bar", fg red), ("foo", bg cyan)]) == red `on` cyan
attrMapLookup (attrName "foo" <> attrName "bar") (attrMap (bg blue) [(attrName "foo", fg red)]) == red `on` blue
```
forceAttrMap :: Attr -> AttrMap

brick Brick.AttrMap

Create an attribute map in which all lookups map to the same attribute. This is functionally equivalent to attrMap attr [].
forceAttrMapAllowStyle :: Attr -> AttrMap -> AttrMap

brick Brick.AttrMap

Create an attribute map in which all lookups map to the same attribute. This is functionally equivalent to attrMap attr [].

basic-prelude	CorePrelude

basic-prelude	CorePrelude

basic-prelude	CorePrelude

brick	Brick.AttrMap

brick	Brick.AttrMap

brick	Brick.AttrMap

brick	Brick.AttrMap

brick	Brick.AttrMap

brick	Brick.AttrMap

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