Recommend spago's --watch feature in automatic reload instructions

[jhrcek]

In https://github.com/JordanMartinez/learn-halogen/blob/latestRelease/src/01-Static-HTML/01-Static-HTML.md#automatic-reload there's a recommendation of using watchexec tool for automatic rebuilding of purs source files. Instead of introducing another external tool, it might be better to recommend spago's --watch feature which achieves the same without requiring external tool. I can make a PR if you agree with my proposal.

[JordanMartinez]

@milesfrain Since you added #63, do you care to comment on this?

[JordanMartinez]

@jhrcek If we don't here from milesfrain in 3 days, then go for it. AFAICT, they do the same thing but the watchexec install is not necessary. I think I thought watchexec did more than just recompile the code (e.g. reload the page, too).

[jhrcek]

When you have parcel serve ... running in one terminal window and run spago build --watch ... in another terminal it reloads the code live in the browser after saving the .purs file in the editor, so to me it feels functionally equivalent to using watchexec.

[JordanMartinez]

Functionally equivalent, yes, but the extra terminal window may put off others, too. I think I found that part annoying myself. That could be fixed if there was Spago-integration for Parcel.

[milesfrain]

@jhrcek I agree with your proposal.

I added this note after reading purescript/spago#65, but somehow missed that the --watch flag also works with bundle-app.

A small annoyance with either of these workflows is that there's a fairly noticeable delay between file save and page reload (at least on my slower machine). It may be nice to encourage some other faster options, such as psc-ide + parcel (demonstrated here). Another possibility is to configure this learning repo with purescript-halogen-storybook, so users can jump to the next example without running another rebuild command.

[JordanMartinez]

Ok, @jhrcek would you mind submitting a PR that removes watchexec and uses spago with the -w flag instead?

Another possibility is to configure this learning repo with purescript-halogen-storybook, so users can jump to the next example without running another rebuild command.

I like this idea. Let's track this in another issue.