# When designing a macro, what is the best error type to throw for what could be see
**URL:** https://discourse.julialang.org/t/when-designing-a-macro-what-is-the-best-error-type-to-throw-for-what-could-be-see/54451
**Category:** General Usage
**Created:** [February 2, 2021, 11:38am UTC](https://discourse.julialang.org/t/when-designing-a-macro-what-is-the-best-error-type-to-throw-for-what-could-be-see/54451 "2021-02-02T11:38:30Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@BridgeBot](https://discourse.julialang.org/u/BridgeBot)
#### Post date: [February 2, 2021, 11:38am UTC](https://discourse.julialang.org/t/when-designing-a-macro-what-is-the-best-error-type-to-throw-for-what-could-be-see/54451/1 "2021-02-02T11:38:30Z")
When designing a macro, what is the best error type to throw for what could be seen as a “syntax error”?
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### Author:  [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)
#### Post date: [February 2, 2021, 3:14pm UTC](https://discourse.julialang.org/t/when-designing-a-macro-what-is-the-best-error-type-to-throw-for-what-could-be-see/54451/2 "2021-02-02T15:14:28Z")
in [DataFramesMeta](https://github.com/JuliaData/DataFramesMeta.jl/blob/master/src/DataFramesMeta.jl) we throw `ArgumentError`s, I guess because the macros in DataFramesMeta are “functon-like”.
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### Author:  [@heetbeet](https://discourse.julialang.org/u/heetbeet)
#### Post date: [February 3, 2021, 5:07am UTC](https://discourse.julialang.org/t/when-designing-a-macro-what-is-the-best-error-type-to-throw-for-what-could-be-see/54451/3 "2021-02-03T05:07:28Z")
[Dhairya](https://app.slack.com/team/UC4QQPG4A) [17 hours ago](https://julialang.slack.com/archives/C6A044SQH/p1612267818381900?thread_ts=1612265889.379200&cid=C6A044SQH)
Depends on the context. If you’re producing invalid regular Julia then the compiler would error for you, if it’s a DSL, then you might want to throw a custom exception if you can catch the exact issue - that would be more informative, or else an `ErrorException` would do
[Heetbeet](https://app.slack.com/team/U018FJVBXPD) [17 hours ago](https://julialang.slack.com/archives/C6A044SQH/p1612269104382100?thread_ts=1612265889.379200&cid=C6A044SQH)
Thanks, yes it’s a DSL. I think I’ll then go with ErrorException
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### Author:  [@heetbeet](https://discourse.julialang.org/u/heetbeet)
#### Post date: [February 3, 2021, 5:09am UTC](https://discourse.julialang.org/t/when-designing-a-macro-what-is-the-best-error-type-to-throw-for-what-could-be-see/54451/4 "2021-02-03T05:09:19Z")
I see `ErrorException` is basically the same type of error you would get with an actual syntax error. So that is probably the closest to the real deal, but `ArgumentError` is probably the most helpful when you are in the pre-processing the macro arguments phase.