[Qute] Debugging Qute template

[angelozerr]

It should be very nice if we could debug with breakpoint a Qute template by using https://microsoft.github.io/debug-adapter-protocol/

@maxandersen @mkouba what you think with this idea?

[maxandersen]

if Qute ends up generating bytecode for all its code rather than just interpret it then this should "just work" assuming we can generate proper source maps.... for now I believe Qute does interpret its while/for loops rather than generate it... question for @mkouba how far away this is.

[mkouba]

Indeed, we don't compile the templates into bytecode. Instead, we parse a template into a tree of Java objects (nodes) and then execute these nodes when rendering the template at runtime. Also note that Qute resolves the nodes/expressions asynchronously and once everything is ready we synchronously build the output.

[angelozerr]

Indeed, we don't compile the templates into bytecode.

Great, so we will able to do like the old FreeMarker debugger support https://github.com/apache/freemarker/tree/a03a1473b65d9819674b285a0538fed824f37478/src/main/java/freemarker/debug

The basic idea is to add/remove a BreakPoint in the Template and when template is rendered, the debugger suspend the process until debugger is re-run.

Also note that Qute resolves the nodes/expressions asynchronously and once everything is ready we synchronously build the output.

We will need to experiment how to support that.

@maxandersen @mkouba do you like this idea about debugging Qute template?

[angelozerr]

@maxandersen @mkouba do you like this idea about debugging Qute template?

[mkouba]

It might be useful but IMO a low priority feature...

[angelozerr]

I have started to write a POC in my spare time, and for the moment I can stop to the defined breakpoint: