git ssb - computed: bypass broadcast by returning computed.NO_CHANGE

Matt McKegg committed on 7/20/2016, 4:08:58 AM
Parent: 2225e7077f112ee10318157443adbbdb5748a50e

changed

computed.jsView
		@@ -1,15 +1,18 @@
1	1 …	/* A lazy binding take on computed */
2	2 …	// - doesn't start watching observables until itself is watched, and then releases if unwatched
3	3 …	// - avoids memory/watcher leakage
4	4 …	// - attaches to inner observables if these are returned from value
5		-// - doesn't broadcast if value is same as last value (and is `value type` or observable, can't make assuptions about reference types)
	5 …	+// - doesn't broadcast if value is same as last value (and is `value type` or observable - can't make assuptions about reference types)
	6 …	+// - doesn't broadcast if value is computed.NO_CHANGE
6	7 …
7	8 …	var resolve = require('./resolve')
8	9 …	var isObservable = require('./is-observable')
9	10 …
10	11 …	module.exports = computed
11	12 …
	13 …	+computed.NO_CHANGE = {}
	14 …	+
12	15 …	function computed (observables, lambda) {
13	16 …	if (!Array.isArray(observables)) {
14	17 …	observables = [observables]
15	18 …	}
		@@ -97,8 +100,13 @@
97	100 …
98	101 …	if (changed \|\| !initialized) {
99	102 …	initialized = true
100	103 …	var newComputedValue = lambda.apply(null, values)
	104 …	+
	105 …	+ if (newComputedValue === computed.NO_CHANGE) {
	106 …	+ return false
	107 …	+ }
	108 …	+
101	109 …	if (newComputedValue !== computedValue \|\| (isReferenceType(newComputedValue) && !isObservable(newComputedValue))) {
102	110 …	if (releaseInner) {
103	111 …	releaseInner()
104	112 …	inner = releaseInner = null

Matt McKegg / mutant