KingCode

Spike

I looked into the state of GraalVM and Clojure and wrote some small work-related scripts.

GraalVM Build Tools

Downloaded GraalVM and set $GRAALVM_HOME
Found two main libraries for building GraalVM CLIs - https://github.com/luchiniatwork/cambada#packaging-as-a-native-image and https://github.com/taylorwood/clj.native-image (or https://github.com/taylorwood/lein-native-image for the lein equivalent). I chose clj.native-image as it seemed more focused on doing one thing well.
First tried its template example which was easy to follow.
Then added a graalvm build to one of our small cli tools
Found it to be pretty straightforward except for a stdout flushing issue that was trivial to fix

delete from a vector

Clojure's vectors let you efficiently get a value given an integer index. Often, I want to remove a value from a vector at a certain index. This doesn't exist in the core library, so I wind up writing it each time. The question is how to do it in an efficient way?

Here's the task: write a function delete-at that takes a vector and an index and returns a new vector with the item at the index removed. The new vector should be one shorter than the argument.

(defn delete-at [v i]
  ;; your code here
 )

Introduction

Stuart talking about them as part of the Day of Datomic videos:

https://youtu.be/ZP-E2IgqKfA?t=2412

Simple data structure

Simple data structure for anomalies.

First start up the REPL by issuing this command:

clj -Sdeps '{:deps {github-mfikes/e00202b2de7cc2352fedcf92b1fe60dc {:git/url "https://gist.github.com/mfikes/e00202b2de7cc2352fedcf92b1fe60dc" :sha "68ef581813e08a92bd52e7beeea1535ab7b3337f"}}}' -m cljs.main -i @index.cljs -r

Once the REPL is waiting for the browser to connect, if it doesn't automatically, open http://localhost:9000 in your browser.

You will now be running Bocko. The following forms evaluated in the REPL will draw an American flag.

Usage

Start up the new cljs.main with Node:

clj -Sdeps '{:deps {org.clojurescript {:git/url "https://github.com/clojure/clojurescript" :sha "3f4084efcb5cd92cceb8ca30765144691d8cfd7e"}}}' -m cljs.main -re node

The above works by specifying ClojureScript as a "git dep" and you can ensure that you are running the very latest by replacing the :sha value with the latest commit SHA at https://github.com/clojure/clojurescript.

Using JavaScript Libraries from ClojureScript

Using JavaScript libraries from ClojureScript involves two distinct concerns:

Packaging the code and delivering it to the browser
Making ClojureScript code that accesses JavaScript libraries safe for advanced optimization

Right now, the only single tool that solves these probems reliably, optimally, and with minimal configuration is shadow-cljs, and so that is what I favor. In paricular, shadow-cljs lets you install npm modules using npm or yarn and uses the resulting package.json to bundle external dependencies. Below I describe why, what alternatives there are, and what solutions I disfavor at this time.

	#!/usr/bin/env bash
	#_" -- mode: clojure; --"
	#_(
	"exec" "clojure" "-Sdeps" "{:deps {borkdude/grasp {:git/url \"https://github.com/borkdude/grasp\" :sha \"6315cea8c0b6dafc7b1eef9ccd03d6d5590d2045\"}}}" "-M" "$0" "$@"
	)

	(require '[clojure.java.io :as io]
	'[clojure.spec.alpha :as s]
	'[clojure.string :as str]
	'[grasp.api :as g])

	;;; http://johnj.com/from-elegance-to-speed.html
	;;;
	;;; The author of the above blog post says that his `smt-8` was slow so he re-wrote it in
	;;; Common Lisp and got nearly 300x improvement. I wrote some pure Clojure variations
	;;; showing much improved performance over the original.
	;;;
	;;; Criterium for benchmarking: https://github.com/hugoduncan/criterium/

	(ns miner.smt
	(:require [criterium.core :as cc]))

	;;; package --- Fix permissions for Emacs.app on macOS Catalina
	;;; Author: Artem Loenko
	;;; Mail-To: <[email protected]>
	;;; Commentary:
	;;; Code:

	(defconst _default-emacs-app-plist-path "/Applications/Emacs.app/Contents/Info.plist")
	(defconst _temp-buffer-name "fixing Emacs permissions")
	(defconst _temp-buffer (get-buffer-create _temp-buffer-name))
	(with-current-buffer _temp-buffer (erase-buffer))

	(ns defwrapper
	(:require [clojure.string :as str]))

	(set! warn-on-reflection true)

	(defn class-methods [^Class class]
	(seq (.getMethods class)))

	(defn constructors [^Class klazz]
	(.getDeclaredConstructors klazz))