Initial values of signals in `inputs` are discarded about purescript-pux HOT 3 CLOSED

I don't know why Elm and subsequently purescript-signal settled on this behaviour

It's the only behavior possible. A signal only has one value at any point in time. Signal a -> Signal a -> Signal a can't return Signal (List a), so one value must be chosen. Conceptually, a Pux app has one signal of actions and signal values/actions only "occur" discretely one-at-a-time.

If you need an initial route, window dimension, and time, then you set those in your initialState. There's no need for actions to control initial state. This could be documented better - I'll add it to the roadmap

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It's the only behavior possible. A signal only has one value at any point
in time. Signal a -> Signal a -> Signal a can't return List a, so one
value must be chosen. Conceptually, a Pux app has one signal of actions
and actions only occur discretely one-at-a-time.

Sorry, if I wasn't clear on this. I'm not suggesting for merge to return a List a as that would be impossible, like you said. Rather, I would (naively?) expect merge to behave similar to the merge from RxJS which never discards a value but instead emits them one after the other.

It seems that some people in the Elm community have been tripped up by this behaviour, too.
The fairMerge function was written to address exactly this issue, though it has not been officially endorsed (yet?).

If you need an initial route, window dimension, and time, then you set
those in your initialState. This could be documented better - I'll add
it to the roadmap

Cool, thanks.

from purescript-pux.

I just had a similar issue, I needed the current route to initialize the whole app.
I passed it manually from JS to the initialState as suggested by @alexmingoia :

var Main = require('../src/Main.purs');
var initialState = require('../src/Application.purs').init;
var debug = process.env.NODE_ENV === 'development'
var currentUrl = window.location.pathname + window.location.search

if (module.hot) {
    var app = Main[debug ? 'debug' : 'main'](window.puxLastState || initialState(currentUrl))();
    app.state.subscribe(function (state) {
     window.puxLastState = state;
    });
    module.hot.accept();
} else {
    Main[debug ? 'debug' : 'main'](initialState(currentUrl))();
}

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