August 2020 Monthly Update

By Alyssa Parado

Welcome to the first (half) month of updates from our new projects.


August 16-31

First goal is to get a stable release of Malli out. This has involved some hammock time, revisiting the design decisions and both designing and implementing features that still could effect the shape of the core apis. And a lot of refactoring. Work is mostly tracked via #116.

Done stuff

Simple Schemas




August 16-31

Continued support for Practicalli by Clojurists together is much appreciated and there are several hundred content ideas for the continued work.

Highlights of the last two weeks includes:

Clojure WebApps

Continuing the Banking on Clojure project as a major project, which started from the specifications created in Practicalli study group and will be expanded into a production grade web application.

The application server system, UI, routing and initial handler have been defined and CircleCI used for system integration and generative testing, deploying to a staging environment on Heroku on successful builds.

Currently adding content for database connectivity, database design and using next.jdbc and H2 for a development environment database.

PostgreSQL provisioned using Heroku for staging and production database. Explored JDBC database connection strings, understanding well formed jdbc connection strings, very useful for working with Heroku environment variable for Postgres databases. Using different variations on the db-spec mapping for next.jdbc to minimise the number of environment variables to create.

Once the project is completed with compojure, other routing libraries (bidi, reitit) will be used to show a working comparison, communicating the different approaches taken in a practical way. The same will be done for component lifecycle libraries, eg. mount, integrant and component.

Clojure deps.edn

Added new aliases and updated existing aliases

[Additional aliases added for lambdaisland/kaocha][] to support ClojureScript test runner, BDD style tests, code coverage and junit-xml reports for CI tools and wall-boards.

Practicalli Clojure

Added several small projects to help people learn the basics of Clojure, many of which cover the concept of data transformation using the Clojure standard library.

Added docs to use CIDER and Calva with REBL

Conjure - vim tooling for Clojure development

Expanding the Clojure aware tools recommendations with Conjure, an excellent development environment for Neovim.

Created a install walk through guide for Conjure that supports those new to Neovim (as I was) which will be added to the Clojure aware editors section in Practicalli Clojure. Also adding an example init.vim configuration that is documented and explains the purpose of the plugins included, supporting the adoption of the Conjure tool.

Planning a video of a REPL based workflow using Conjure (and all other editors) to show the tool in action and support effective.


August 16-31

Here is an overview of the work I did per project. During this period I focused mostly on a new babashka release, v0.2.0. Most of the issues worked on in sci also end up in babashka.


I also started to work on babashka.process, a library that will make it easier to work with java.lang.ProcessBuilder. This did not yet end up in a release.

Another sub-project I started working on is integrating clojure.spec with babashka (#558). It’s unclear if this will make it in babashka, but it will give me an idea if it’s feasible at all. According to a poll 60% of babashka user like to wait for spec2. An option is to include spec1 under a feature flag for those who like to compile babashka on their own machines. Here is a Github issue where you can post your ideas on this.





August 16-31

In the first iteration we started working primarily on analysis and planning on the following issues:

Datomic API

A comparison project was created that calls common functions from Datomic and Datahike in order to find out what functions differ. The result from this iteration will be a report that highlights the differences.

Entity Specs

Datomic’s entity specs ( were analysed and a first draft for Datahike’s system schema was derived. Further planning for integration into the current transactor was done.


Homogeneous tuple value types were analysed both in DataScript and Datomic ( in order to understand the differences and to define a proper design that would fit well within our system schema.