Topic based stream splitter. Applies topic function to each received value and only forwards it to the child subscriptions of the returned topic.
remarks
The actual topic (return value from topic fn) can be of any type, apart from undefined. Complex topics (e.g objects / arrays) are allowed and they're matched with registered topics using {@link @thi.ng/equiv#equiv} by default (but customizable via equiv option). Each topic can have any number of subscribers.
If a xform transducer is given, it is always applied prior to passing the input to the topic function. I.e. in this case the topic function will receive the transformed inputs.
PubSub supports dynamic topic subscriptions and unsubscriptions via {@link PubSub.(subscribeTopic:1)} and PubSub.unsubscribeTopic. However, the standard {@link ISubscribable.(subscribe:1)} / ISubscribable.unsubscribe methods are NOT supported (since meaningless) and will throw an error! unsubscribe() can only be called WITHOUT argument to unsubscribe the entire PubSub instance (incl. all topic subscriptions) from the parent stream.
Topic based stream splitter. Applies
topicfunction to each received value and only forwards it to the child subscriptions of the returned topic.The actual topic (return value from
topicfn) can be of any type, apart fromundefined. Complex topics (e.g objects / arrays) are allowed and they're matched with registered topics using {@link @thi.ng/equiv#equiv} by default (but customizable viaequivoption). Each topic can have any number of subscribers.If a
xformtransducer is given, it is always applied prior to passing the input to the topic function. I.e. in this case the topic function will receive the transformed inputs.PubSub supports dynamic topic subscriptions and unsubscriptions via {@link PubSub.(subscribeTopic:1)} and PubSub.unsubscribeTopic. However, the standard {@link ISubscribable.(subscribe:1)} / ISubscribable.unsubscribe methods are NOT supported (since meaningless) and will throw an error!
unsubscribe()can only be called WITHOUT argument to unsubscribe the entirePubSubinstance (incl. all topic subscriptions) from the parent stream.