Remote Require for Clojure

Require any Clojure snippet on-the-fly from anywhere in the Internet!

Rationale

For example, James Reeves wrote a library of useful utility functions, medley. But you don’t need everything from it, you need just assoc-some. It would be a waste to include a whole library just to use a single function!

Meet Remote Require!

Usage

0. Add remote-require dependency to your project (just once):

io.github.tonsky/remote-require {:git/sha "c9027682287f48cd89450839b18e6c69758fc343"}

1. Go to the file you are interested in, e.g. src/medley/core.cljc
2. Find a function that you need, e.g. assoc-some
3. Include it!

(require '[remote-require.core :as rr])

(rr/from "https://github.com/weavejester/medley/master/src/medley/core.cljc"
  :require [assoc-some])

That’s it! Now you can use it freely:

(assoc-some {}
  :a 1
  :b nil
  :c 3) ; => {:a 1, :c 3}

Examples

; File in Github repo
(rr/from "https://github.com/weavejester/medley/d1e00337cf6c0843fb6547aadf9ad78d981bfae5/src/medley/core.cljc"
  :require [dissoc-in assoc-some regexp?])

; Gist
(rr/from "https://gist.githubusercontent.com/calebphillips/240dd6162aefb77584a88249b009fbe6/raw/d8b5a865e7a58bab7da48493a64db848d4f8c0f5/cal.clj"
  :require [left-pad right-pad])

; Twitter
(rr/from "https://twitter.com/nikitonsky/status/1584629264909225984"
  :require [zip now clamp between?])

Highlights

• Works directly from the REPL, no restart required
• Caches fetched pages locally (in ~/.clj-remote-require), so will work offline after initial fetch
• Can import functions, variables and macros
• Only imports what you explicitly asked for, stripping away everything else
• Allows reasonable amount of extra text in sources (as long as it can’t be confused with Clojure code)

Supported sources

• Github
• Gist (only RAW output)
• Twitter
• Anything else that serves “clean enough” HTML page

How does it work?

What happens under the hood is:

• URL is fetched
• Resulting page is cached locally for future repeated imports
• Clojure part of HTML is parsed
• (defn <your-symbol> ...) is found
• Macro outputs defn content into current namespace
• If something goes wrong, exception is thrown

Best practices

• Try to refernce immutable sources like Github + SHA or Twitter
• In Github, press Y to switch from master to current SHA

Limitations

• Does not resolve dependencies or namespace aliases
• If one fn depends on the other, importing both should work though

; Github repo, `map-keys` depends on `editable?` and `reduce-map`
(rr/from "https://github.com/weavejester/medley/blob/master/src/medley/core.cljc"
  :require [editable? reduce-map map-keys])

• Can’t import functions with the same name from different sources (one will override another)