Pushup creator here. We're interested in feedback on the design. Pushup introduces a new lightweight template syntax that mixes Go code and HTML in the same page; pages are then compiled down to pure Go, relying on the net/http package. Pushup uses file-based routing, so adding a page adds a route to your app. The template language has an "inline partials" feature to make it easier support for modern hypermedia libraries like htmx in mind. Would love to know what the Go web development community thinks.
Here is a short demo of Pushup in action: https://www.youtube.com/watch?v=nkyiATkZ4Js
This is much nicer syntactically than using the Go html/template engine, but it seems roughly equivalent in expressive power. Are you converting your "up" syntax into go templates with the Go expressions extracted into compiled Go code, referenced be the templates, out of curiosity? If so, the way you've transparently handled interleaving (such as html elements in the for loop) is really cool.
How would your go scripting interact with JS? For example, say that I have a backend API that the fronted calls into. In your design, would I call out into Go to perform the http request, or would I do this in JS? I'm sure both would work - since the Go request would be handled server side and simply slow down static page generation, but it seems like calling into Go might not be the right thing to do for a more responsive AJAX app. Do you envision mixing Up/JS in the same pages? Can I do crazy stuff like use JS to insert a variable (by value probably) into your Go code, or vice versa?
Over the years, I've learned that web front ends are positively bonkers in the kinds of things they want to do, and when you are the developer of any kind of frameworks, you end up suffering greatly if you insert yourself into middle of that ecosystem, since you will be asked to support features that you never dreamed of. If you support them, the framework gets more use, if you don't, the cool kids move onto other things.
I've tried to tackle a much simpler problem with a project of my own [1], which is a backend server code generator to make implementing JSON models more easily from an OpenAPI spec, and I've found that even in this relatively simple concept, the limitations of a strictly, statically typed language like Go end up running into incredible complexity due to the dynamic nature of web frontends and JSON. Outside of trivial strings and numbers, you start running into the limits of the Go typing system.
Anyhow, good luck, this is very cool and it seems like a fun thing to play with.