https://github.com/randomcorp/thread-first-thread-last-backwards-question-mark-as-arrow-cond-arrow-bang

The exciting new ->->><?as->cond->! macro
https://github.com/randomcorp/thread-first-thread-last-backwards-question-mark-as-arrow-cond-arrow-bang

Last synced: about 2 months ago
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The exciting new ->->><?as->cond->! macro

• Host: GitHub
• URL: https://github.com/randomcorp/thread-first-thread-last-backwards-question-mark-as-arrow-cond-arrow-bang
• Owner: randomcorp
• Created: 2018-11-25T05:04:38.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2020-04-02T11:53:53.000Z (almost 5 years ago)
• Last Synced: 2024-08-03T13:04:46.729Z (5 months ago)
• Language: Clojure
• Size: 4.88 KB
• Stars: 524
• Watchers: 11
• Forks: 5
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• stars - randomcorp/thread-first-thread-last-backwards-question-mark-as-arrow-cond-arrow-bang - The exciting new ->->><?as->cond->! macro (⭐️522) (Clojure)
• stars - randomcorp/thread-first-thread-last-backwards-question-mark-as-arrow-cond-arrow-bang - The exciting new ->->><?as->cond->! macro (⭐️523) (Clojure)

README

        
# ->->>cond->!

_As seen in [Every Clojure Talk Ever](https://www.youtube.com/watch?v=jlPaby7suOc) by [Amperity](https://github.com/amperity)_

This is the bread and butter of randomcorp's Clojure code and we're

excited to share it with the world. Have you been frustrated with

always needing to compose the various types of threading macros?

```clojure

(-> []

    (conj 1 2 3)

    (->> (mapv inc))

    (as-> v

      {:vec-of-numbers v})

    (cond->

      (some-pred) (assoc :other-key "other-val")))

```

It would be nice if there were one single macro to do all that for

you. Well, now there is!

```clojure

(->->>cond->!

  []

  :-> (conj 1 2 3)

  :->> (mapv inc)

  :as-> v {:vec-of-numbers v}

  :cond-> (some-pred) (assoc :other-key "other-val"))

```

To short-circuit on nil values (a la `some->`), use `:`:

```clojure

(->->>cond->!

  []

  :-> not-empty

  :

  :-> (conj 1))

;; => nil

```

To make assertions about the values during the threading, use `:!`:

```clojure

(->->>cond->!

  2

  :-> inc

  :! even?)

;; => Error!

```

## License

Free, as in beer.