Christophe Grand cgrand

Accessing super members in ClojureDart

In ClojureDart deftype (and reify) can extend abstract classes and, as a consequence, we need a way to call super implementations (even on fields because of getters/setters).

For example, this Dart

class WebViewExampleState extends State<WebViewExample> {
  @override
 void initState() {

	; early days
	defonce + :watch


	; yesterday
	:managed [*app-state (atom {}) :dispose nil]
	:bind {:app-state app-state}

	...

	;; ClojureDart has structural merge for maps https://github.com/Tensegritics/ClojureDart/commit/ac6bd2a8dec29e31dd2f598a8009ebdffd036781#diff-7d37216e2a92d1019eb7fe5bf292430220b2fcec4cbc2cd3355c6a4226333680R4714

	;; * (merge big-map small-map) and (merge small-map big-map) are equally fast
	;; * (merge original-map modified-map) takes time proportional to the number of modified keys
	;; * even in worst case, it's faster than `into`

	;; BEST CASE
	user=> (let [m (zipmap (range 1e6) (range 1e6))] (time (count (merge {:a 1} m))))
	"Elapsed time: 287.794583 msecs"
	1000001

	;; cond-> inside -> is fine
	(-> input
	(dothis ...)
	(cond-> test (maybe do this also ...))
	(dothat ...))

	;; cond->> inside ->> isn't fine
	(->> input
	(dothis ...)
	(cond->> test (maybe do this also ...)) ; the input seq comes last because of ->> but cond->> expects it first.

	(ns parquet-layout.core)

	(defn destock
	([stock] stock)
	([stock board]
	(let [n (dec (stock board))]
	(if (zero? n)
	(dissoc stock board)
	(assoc stock board n)))))

	(ns workshop.main
	(:require ["package:flutter/material.dart" :as m]
	["package:google_fonts/google_fonts.dart" :as fonts]
	#_["example.dart" :as ex]
	[cljd.flutter.alpha2 :as f]))

	(def normal-text-style
	(fonts/GoogleFonts.sourceCodePro
	.fontSize 26
	.fontWeight m/FontWeight.w700

	(ns tensegritics.expressive.datalog
	"Putting expressions in datomic-flavored datalog :where clauses.")

	;; I (cgrand) believes that datalog literally lacks expressivity because
	;; it's not expression-based but clause-based and thus requires a lot of
	;; gratuitous naming.
	;; Here is an attempt to compiles expressions into clauses.

	(defn- grounded? [[e a v]] (and (keyword? a) (not (symbol? v))))

	;; let's say you want to perform an action only when a state is true and returns true/false depending on the action success
	;; typically I would write

	(if @open ; check state
	(do
	(.put q bytes) ; action
	true)
	false)

	;; or

	;; For ClojureDart in a bout of NIH syndrome we rewrote Clojure for
	;; it seems to be faster because we don't use concat
	(defmacro for
	"List comprehension. Takes a vector of one or more
	binding-form/collection-expr pairs, each followed by zero or more
	modifiers, and yields a lazy sequence of evaluations of expr.
	Collections are iterated in a nested fashion, rightmost fastest,
	and nested coll-exprs can refer to bindings created in prior
	binding-forms. Supported modifiers are: :let [binding-form expr ...],
	:while test, :when test.

	log(String msg, x) {
	print(msg);
	return x;
	}

	var a = log("Init A", 1);
	var b = log("Init B", 2);
	var c = log("Init C", 3);

	main() {