simplify streams, lint docs

stream/scanMerge.js

@@ -0,0 +1,25 @@
+"use strict"
+
+var combine = require("./stream").combine
+
+module.exports = function(tuples, seed) {
+	var streams = tuples.map(function(tuple) {
+		var stream = tuple[0]
+		if (stream._state.state === 0) stream(undefined)
+		return stream
+	})
+
+	var newStream = combine(function() {
+		var changed = arguments[arguments.length - 1]
+
+		streams.forEach(function(stream, idx) {
+			if (changed.indexOf(stream) > -1) {
+				seed = tuples[idx][1](seed, stream._state.value)
+			}
+		})
+
+		return seed
+	}, streams)
+
+	return newStream
+}