96b7f82 · rowtype-yoga/purescript-native

git.iko.soy/rowtype-yoga/purescript-native

Make 'compare on' example idiomatic

commit96b7f82659f74cf1c9ccb1406dcc6fd3cf191ddd authorPhil Freeman <paf31@cantab.net> dateMon 2 Mar 2015, 16:59 (12 years ago) parentfe525f9

2 files changed+8−10

compare with golang

unifiedsplit

prelude/README.md+4−5 prelude/prelude.purs+4−5

prelude/README.md+4−5

@@ -252,7 +252,7 @@ types use the type constructor `f` to represent some computational context.

252252(<#>) :: forall f a b. (Functor f) => f a -> (a -> b) -> f b

253253```

254254

255−`(<#>)` is `(<$>)` with its arguments flipped. For example:

255+`(<#>)` is `(<$>)` with its arguments reversed. For example:

256256

257257```purescript

258258[1, 2, 3] <#> \n -> n * n

@@ -880,14 +880,13 @@ on :: forall a b c. (b -> b -> c) -> (a -> b) -> a -> a -> c

880880

881881The `on` function is used to change the domain of a binary operator.

882882

883−For example, given a function `height :: Person -> Number`, we can create a function which compares two people by height:

883+For example, we can create a function which compares two records based on the values of their `x` properties:

884884

885885```purescript

886−taller :: Person -> Person -> Boolean

887−taller = (>) `on` height

886+compareX :: forall r. { x :: Number | r } -> { x :: Number | r } -> Ordering

887+compareX = compare `on` _.x

888888```

889889

890−

891890#### `Fn0`

892891

893892``` purescript

prelude/prelude.purs+4−5

@@ -234,7 +234,7 @@ module Prelude

234234 class Functor f where

235235 (<$>) :: forall a b. (a -> b) -> f a -> f b

236236

237− -- | `(<#>)` is `(<$>)` with its arguments flipped. For example:

237+ -- | `(<#>)` is `(<$>)` with its arguments reversed. For example:

238238 -- |

239239 -- | ```purescript

240240 -- | [1, 2, 3] <#> \n -> n * n

@@ -868,13 +868,12 @@ module Data.Function where

868868

869869 -- | The `on` function is used to change the domain of a binary operator.

870870 -- |

871− -- | For example, given a function `height :: Person -> Number`, we can create a function which compares two people by height:

871+ -- | For example, we can create a function which compares two records based on the values of their `x` properties:

872872 -- |

873873 -- | ```purescript

874− -- | taller :: Person -> Person -> Boolean

875− -- | taller = (>) `on` height

874+ -- | compareX :: forall r. { x :: Number | r } -> { x :: Number | r } -> Ordering

875+ -- | compareX = compare `on` _.x

876876 -- | ```

877− -- |

878877 on :: forall a b c. (b -> b -> c) -> (a -> b) -> a -> a -> c

879878 on f g x y = g x `f` g y

880879