Printing to the terminal for debugging

Developers Language Support
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If you want to print output to the terminal, for now you can use debugPrint() along with debug_show():

let a: Nat = 10;
debugPrint(debug_show(a));

This outputs to the terminal that’s running dfx start (note this might be a separate window if you’re not using the --background flag).

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Thanks for sharing the Syntax Ori. :ok_hand:

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good hint! did anyone actually make the
print function work?

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yep it works. Have a look on the repo i posted yesterday, there are a few debug prints in it.

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print() alone isn’t working at the moment, it’s been reported to the team.

If you take a look in Guillaume’s repo you’ll see there are type-specific debug prints like debugPrintNat() too.

Another option is importing prelude and using printLn() (which calls debugPrint internally).

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I was about to make a post on this but you beat me to it Ori! Nice syntax alternative for those looking to use a similar print functionality.

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Please note debugPrint has been moved from the default scope and now requires an import:

import Prim “mo:prim”;

let a: Nat = 10;
Prim.debugPrint(debug_show(a));
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did you actually manage to import mo:Prim ? didn’t work for me somehow :face_with_monocle:

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Lower case p in mo:prim?

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the problem was that i used import Prim „mo:prim.mo“ instead of import Prim „mo:prim“. that error is kind of weird because all other imports i use have the .mo suffix and work like a charm? is this because prim is not part of the stdlib? @claudio

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So re this, the .mo extensions in imports will possibly be removed in the next version.

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Updating this for recent releases:

import Debug “mo:base/Debug”;

let a: Nat = 10;
Debug.print(debug_show(a));
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