IO.println: Type error: expected str to be Text, but got Function

[JaroslavTulach]

I am trying to use IO.println to "debug" my #5956 program. However the println statement is causing my program to fail with:

Execution finished with an error: Type error: expected `str` to be Text, but got Function.
        at <enso> IO.println(Internal)
        at <enso> Function.<|(Internal)

It is not really productive when debugging of something turns into hunting for a reason why the debugging itself does not work. I believe the IO.println method should never fall and always print something.

The reproducer is:

from Standard.Base import all
import Standard.Base

main = 
    raw = Vector.from_polyglot_array []
    IO.println <| (Meta.type_of raw).to_text
    IO.println <| (Meta.type_of raw)
    Meta.type_of raw

surprisingly the 1st IO.println statement succeeds and prints:

Vector.type.to_text[Vector.enso:601-1763]

however the second statement yields the exception Type error: expected str to be Text, but got Function..

[jdunkerley]

Given that IO.println not supported well within the IDE, this is not on milestone.
It could make for a nice first ticket where the value is to_textd if not Text.

[wdanilo]

@jdunkerley default to to_text is nice, but I think the problem here is more serious. If I understand that correctly, engine thinks that the right side of print here IO.println <| (Meta.type_of raw) is a not-evaluated function. If so, this is something really broken. Do I understand it correctly?

[JaroslavTulach]

Given that IO.println not supported well within the IDE, this is not on milestone.

When IO.println is crashing the execution, it is hard to fix anything - including the IDE. Ignoring the problem will strike back.

It could make for a nice first ticket where the value is to_textd if not Text.

I am not sure. I certainly found the logic of to_(display)_text when printing an error very convoluted. Otherwise I'd fix it without reporting an issue. Good luck to a newcomer who selects this a a fist issue.

[wdanilo]

Good luck to a newcomer who selects this a a fist issue.

😂 We should probably then remove this flag :D