Hi,

JuMP’ style guide states we should prefer `in`

over `=`

in for loops: http://www.juliaopt.org/JuMP.jl/stable/style/#for-loops-1

I was wondering why it is not the same for variables and constraints declaration as in the documentation we can find `@variable(model, x[i=1:4; mod(i, 2)==0])`

instead of `@variable(model, x[i in 1:4; mod(i, 2)==0])`

. Is there a reason for choosing `=`

in this case?

Thank you

Rémi Garcia

# Style guide: in or =

Good question, I don’t think we’ve explicitly considered this, but I agree that it should be covered by the JuMP style guide. My initial response is that `in`

(with required spaces before and after) is 4x as many characters as `=`

. It’s common to have multiple indices like this for a variable, e.g., `@variable(model, x[i=1:N, j=1:N, k=1:N])`

, so the effect of the extra characters is may be more significant than for regular `for`

loops.

See also the discussion at https://github.com/domluna/JuliaFormatter.jl/pull/70.

I understand your point, thanks!

I’ve always few constraints that have too many characters anyway. Hence I have to add breaks after the indices and a few characters are not a problem. Thanks for the link to the discussion, that was really interesting too.