Support returning functions in match patterns

[MaaaxiKing]

Describe the project you are working on

Reaction game

Describe the problem or limitation you are having in your project

I cannot check for a text with tr() in match.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

You could use any function that returns something as a pattern in a match statement.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

match $Label.text:
	tr("foo"):
		print("hi")
	tr("bar"):
		print("ha")

If this enhancement will not be used often, can it be worked around with a few lines of script?

No

Is there a reason why this should be core and not an add-on in the asset library?

Yes, it's useful for everyone and not even possible to implement with an asset afaik.

[Calinou]

Try this instead:

match tr($Label.text):
	"foo":
		print("hi")
	"bar":
		print("ha")

The values of match blocks must be constant expressions. This is likely done in the interest of performance, so they only have to be evaluated once when the script is compiled.

[MaaaxiKing]

I tried and it did not work which also surprised me.

[MaaaxiKing]

What you wrote makes that if the Label's text is "MY TEXT.", it will check if there's a translation with the key "MY TEXT." instead of checking for the translation.

[Calinou]

@MaaaxiKing Out of curiosity, what's the end goal here? What are you trying to achieve?

[MaaaxiKing]

I have a tutorial and there's text to display. Everytime the user does what he has to, I call next() and there I want to check what the current text ist. My current way is that I have a variable: index. And in next() I check for this with match and at the end of the function I increase index by 1.

[Calinou]

I have a tutorial and there's text to display. Everytime the user does what he has to, I call next() and there I want to check what the current text ist. My current way is that I have a variable: index. And in next() I check for this with match and at the end of the function I increase index by 1.

I think you should have a separate variable that stores the untranslated text key at all times and use that for the match comparison instead. I wouldn't recommend relying on translated text for logic that can impact your game's behavior.

[DaGamingWolf]

i fully support this. it seems incredibly weird not to be able to use anything in a match statement that isn't a constant. it has hugely limited my code. i keep running into this over and over again. can't use variables as a pattern? this is silly. you should easily be able to compare a string with a bunch of different node names that vary because you have no idea what those names will be. if if statements can do it, there's no reason a match statement shouldn't also be able to.

[DaGamingWolf]

maybe this is the reason variables can no longer be used in match statements in 4.0. setters and getters return the value, and have been linked with declaration of variables. the loss of the ability to use variables in match statements is way to huge a loss imo not to reconfigure match to allow returning values for comparison.

[dalexeev]

• Resolved by GDScript: Allow variables in match patterns godot#72285.