pastry

A donut.system plugin for transforming declarative definitions into components.

Project status

Alpha

This library is a proof of concept. Use at your own risk. Issues and PRs are welcome!

Installation

Latest version: 0.0.14 (tag v0.0.14)

Clojars

deps.edn

xyz.psyclyx/pastry {:mvn/version "0.0.14"}

Leiningen/Boot

[xyz.psyclyx/pastry "0.0.14"]

Usage

pastry-plugin finds and transforms component definitions, allowing you to define components with simple data instead of full donut.system maps.

Snippets in this section assume the following requires:

(require
  '[donut.system :as donut]
  '[psyclyx.pastry :as pastry])

Default Usage

By default, pastry transforms maps containing a ::pastry/type key. Component creation logic is defined with a defmethod for pastry/->component.

(defmethod pastry/->component :my-app/greeter
  [{:keys [greeting]}]
  {::donut/start (constantly greeting)})

(def system
  {::donut/plugins [pastry/pastry-plugin]
   ::donut/defs
   {:app {:greeter {::pastry/type :my-app/greeter
                    :greeting "Hello, pastry!"}}}})

(-> (donut/signal system ::donut/start)
    (get-in [::donut/instances :app :greeter]))
;; => "Hello, pastry!"

Custom Usage

For more flexibility, the target predicate and transformation function can be configured at the system level.

(def system
  {::donut/plugins [pastry/pastry-plugin]
   ::pastry/target? string?
   ::pastry/->component (fn [s] {::donut/start (constantly (count s))})
   ::donut/defs
   {:app {:string-length "a string definition"}}})

(-> (donut/signal system ::donut/start)
    (get-in [::donut/instances :app :string-length]))
;; => 19

Contributing

Issues and pull requests welcome!

(Un)license

This is free and unencumbered software released into the public domain.