Safe Haskell | None |
---|---|

Language | Haskell2010 |

## Synopsis

- type IxGetter i s a = Optic' A_Getter (WithIx i) s a
- ito :: (s -> (i, a)) -> IxGetter i s a
- selfIndex :: IxGetter a a a
- iview :: (Is k A_Getter, is `HasSingleIndex` i) => Optic' k is s a -> s -> (i, a)
- iviews :: (Is k A_Getter, is `HasSingleIndex` i) => Optic' k is s a -> (i -> a -> r) -> s -> r
- data A_Getter :: OpticKind

# Formation

# Introduction

ito :: (s -> (i, a)) -> IxGetter i s a Source #

Build an indexed getter from a function.

`>>>`

('i','x')`iview (ito id) ('i', 'x')`

selfIndex :: IxGetter a a a Source #

Use a value itself as its own index. This is essentially an indexed version
of `equality`

.

# Elimination

iview :: (Is k A_Getter, is `HasSingleIndex` i) => Optic' k is s a -> s -> (i, a) Source #

View the value pointed to by an indexed getter.

iviews :: (Is k A_Getter, is `HasSingleIndex` i) => Optic' k is s a -> (i -> a -> r) -> s -> r Source #

View the function of the value pointed to by an indexed getter.

# Subtyping

data A_Getter :: OpticKind Source #

Tag for a getter.