Macros and DSLs

[zenon]

I try out Soss.jl, a tool for probabilistic programming.

I can't attach .jl files, so I changed them to txt.

This (non Pluto) works fine:
sosstest01.txt

This (Pluto) doesn't:
sosstest02.txt

Error message:
Cyclic references among m, y and forwardModel:
Combine all definitions into a single reactive cell using a begin ... end block.

Am I doing sth wrong, or has Pluto an issue with macros?

Kind greetings, z.

[fonsp]

Pluto doesn't understand macros, it just looks at the code as if the macro wasn't there.

For example, if a macro turns

@hello dog

into

dog = 123

then Pluto things that this cell references dog, and that it does not assign to it. This leads to all sorts of problems - one being that the scope can't be managed properly, and you get an error like rafaqz/UnitfulMoles.jl#12

---

This is a difficult problem: the macro is not known to Pluto - it is only defined inside the notebook process. To understand (i.e. expand) macros, there needs to be an analysis step after normal analysis, but before runtime (because the analysis determines which cells will run).

So Domain Specific Languages like Soss.jl might not work well.

[zenon]

Hello Fons, thank you for the fast answer.

Hm. I was afraid it would come out this way. :-)

Kind greetings, z.

[fonsp]

About DSLs: I am thinking that maybe Pluto can include a "mock version" for a bunch of popular packages with DSLs.

So not the original macro, but a macro that transforms the code into something that has the intended references and definitions. For example, Replace=with~.jl could transform

@replaceit x ~ y + 1

(Pluto thinks that x, y and + are the references, with no assignments)
to

x = y + 1

Another example

Another example is @bind inside Pluto:

@bind x Slider(1:3)

looks like a reference to x, but it is actually an assignment to x. This one is solved by expanding the macro (because @bind is available inside the Pluto package).

[fonsp]

Although, looking at this issue again - the problem is not the DSL, it's a bug in Pluto's syntax analysis! #225

[fonsp]

Your original issue should be fixed now! But the DSL problem is still there

[zenon]

Yes! It now works (even if I understand that there are no guarantees :-) )

Thank you for the hint.

(Sorry for the late answer. I took an offline time ....)