The crux is that I want to build a string programmatically with a variable number of elements and can’t find a way to do it with @sprintf julia> bnds = [1,2,3]; julia> @sprintf("%d,%d,%d,",bnds...) "1,2,3," julia> repeat("%d,",3) "%d,%d,%d," julia> @sprintf(repeat("%d,",3),bnds...) ERROR: LoadErr…

Yes. Because @sprintf is a macro, it can only act on the string literal it’s given. It can’t generate code for repeat(...) since the stuff repeat does is handled at run-time, not parse-time. You can use a for loop to do something similar, right? or map and join?

But if I compute fmt = repeat("%d,",3) "%d,%d,%d," and pass the fmt, which is a string, the error is the same. Yes, I can create my final sting some other way but it looks clumsy.

This problem is more general than this thread suggests. It is not limited to repeated format items. Surely this is a bug: julia> using Printf julia> @sprintf(“aaa %d bbb”, 3) “aaa 3 bbb” julia> fmt = “aaa %d bbb” “aaa %d bbb” julia> @sprintf(fmt, 3) ERROR: LoadError: MethodError: no method ma…

[image] alan: Surely this is a bug No, that’s how macros work: they replace expressions into other expressions. The @sprintf macro expects as first argument a literal string, not a variable whose runtime value is a string: macros can’t possibly access runtime values of variables (unless you …

what you want: julia> fmt = "aaa %d bbb" "aaa %d bbb" julia> Printf.format(Printf.Format(fmt), 3) "aaa 3 bbb"

Thank you. I’m surprised no one has put that into a function called “sprintf”. It would be more useful than the macro.

Is this @sprintf (annoying) behaviour intended?

General Usage

lmiq September 20, 2021, 5:14pm 4

This thread discusses many alternatives for that: How to repeat the format in @printf? - #2 by heliosdrm

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Is this @sprintf (annoying) behaviour intended?

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