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Is there a "cleaner" implementation similar to map's? Yes: let map f = id >=> switch f This follows from two of your other equations: map f = bind (switch f) g >=> h = g >...
Answer
#4: Post edited
by
r~~
·
2024-04-04T04:02:38Z (8 months ago)
- > Is there a "cleaner" implementation similar to `map`'s?
- Yes:
- ```
- let map f = id >=> switch f
- ```
- This follows from two of your other equations:
- ```
- map f = bind (switch f)
- g >=> h = g >> bind h
- ```
- So if you want to get `bind (switch f)` out of `(>=>)`, you can start by making `h = switch f`, then get rid of the superfluous composition by letting `g` be `id` and you're done.
- ```
g >=> h = g >> bind h <------ (h = switch f)= g >=> switch f = g >> bind (switch f)= g >=> switch f = g >> map f <------ (g = id)= id >=> switch f = id >> bind (switch f)- ```
- > Is there a "cleaner" implementation similar to `map`'s?
- Yes:
- ```
- let map f = id >=> switch f
- ```
- This follows from two of your other equations:
- ```
- map f = bind (switch f)
- g >=> h = g >> bind h
- ```
- So if you want to get `bind (switch f)` out of `(>=>)`, you can start by making `h = switch f`, then get rid of the superfluous composition by letting `g` be `id` and you're done.
- ```
- g >=> h = g >> bind h <------ (h = switch f)
- g >=> switch f = g >> bind (switch f)
- g >=> switch f = g >> map f <------ (g = id)
- id >=> switch f = id >> map f
- id >=> switch f = map f
- ```
#3: Post edited
by
toraritte
·
2024-04-03T16:21:24Z (8 months ago)
- > Is there a "cleaner" implementation similar to `map`'s?
- Yes:
- ```
- let map f = id >=> switch f
- ```
- This follows from two of your other equations:
- ```
- map f = bind (switch f)
- g >=> h = g >> bind h
- ```
So if you want to get `bind (switch f)` out of `(>=>)`, you can start by making `h = switch f`, and then you have `g >=> switch f = g >> bind (switch f) = g >> map f`. Get rid of the superfluous composition by letting `g` be `id` and you're done.
- > Is there a "cleaner" implementation similar to `map`'s?
- Yes:
- ```
- let map f = id >=> switch f
- ```
- This follows from two of your other equations:
- ```
- map f = bind (switch f)
- g >=> h = g >> bind h
- ```
- So if you want to get `bind (switch f)` out of `(>=>)`, you can start by making `h = switch f`, then get rid of the superfluous composition by letting `g` be `id` and you're done.
- ```
- g >=> h = g >> bind h <------ (h = switch f)
- = g >=> switch f = g >> bind (switch f)
- = g >=> switch f = g >> map f <------ (g = id)
- = id >=> switch f = id >> bind (switch f)
- ```
#2: Post edited
by
r~~
·
2024-04-02T23:14:54Z (8 months ago)
- > Is there a "cleaner" implementation similar to `map`'s?
- Yes:
- ```
- let map f = id >=> switch f
```
- > Is there a "cleaner" implementation similar to `map`'s?
- Yes:
- ```
- let map f = id >=> switch f
- ```
- This follows from two of your other equations:
- ```
- map f = bind (switch f)
- g >=> h = g >> bind h
- ```
- So if you want to get `bind (switch f)` out of `(>=>)`, you can start by making `h = switch f`, and then you have `g >=> switch f = g >> bind (switch f) = g >> map f`. Get rid of the superfluous composition by letting `g` be `id` and you're done.
#1: Initial revision
by
r~~
·
2024-04-02T21:02:56Z (8 months ago)
> Is there a "cleaner" implementation similar to `map`'s? Yes: ``` let map f = id >=> switch f ```