Idiomatic way to format error messages

[hazy elk]

I have an error set and I want to format it when I want to print the error set, but I cant put a format function in the error set. Whats the idiomatic way to do it

[wide field]

you can use @errorName (mirroring @tagName for enums)

or use the default formatter if you want the full name (with namespace information)

[hazy elk]

yeah but i want to use cusotm error messages yk

like not just the name of the error

for example WindowError.CreationFail => "Failed to create window"

[wide field]

ah
cant add a format method to an error set so i’d just do a fn formatWinError(writer: anytype, e: WIndowError) !void { … }

I personally wouldnt do it like that though since most errors can’t just be “decoded” without a ton of context that only the caller knows

like maybe itll work for you but I doubt it, especially with windows apis
the same error code can mean a million different things depending on the context

[hazy elk]

basically I want to log errors with a nice message, before I was printing at the error site but that seemed like the improper way to do it in zig

[wide field]

if you just want to log it, I’d use the builtin std.log system
you can even add your own scope and use a custom logging function

[hazy elk]

should I log at the error site

[wide field]

Yeah thats where you have the most information

And logs can be overwritten and scoped easily

[hazy elk]

wdym overwritten

[wide field]

*overriden
you can use std.Options to change the behavior easily

[hazy elk]

alr, but it still feels weird to log errors at the error site

[wide field]

Its fairly standard

Only time you wouldn't is if you want them to be handled further down the line

[vocal grove]

your library could provide a error formatter, that takes in writer, error an optional context