Do we need 5 >= x >= 1

[IainNZ]

We support @defVar(m, 5 >= x >= 1), but I'm not sure we really should. I'd be in favour of just making it an error.

[joehuchette]

It is a bit inconsistent that

julia> @addConstraint(m, 5 >= x >= 1)
ERROR: in @addConstraint (5 >= x >= 1): only ranged rows of the form lb <= expr <= ub are supported.

doesn't work.

[mlubin]

I'm not a big fan of the syntax, but not sure if we need to break things now if this is how some people prefer to write down variable bounds.

[IainNZ]

I don't even think its documented, I think it was added in one of the @defVar refactors just because it was possible.

[mlubin]

@yeesian seems to use this syntax in his examples

[IainNZ]

Yeah but that guys crazy ;)

[mlubin]

We'd at least have to deprecate for a version cycle. The syntax is rough on the eyes but it's still clear and easy to understand. We don't have the corresponding syntax for two-sided constraints because variables with upper and lower bounds are much more common than two-sided constraints.
Here's the original commit: a1d0c87

[yeesian]

@yeesian seems to use this syntax in his examples

Oops, did I? I don't mind changing the examples (if any).

[yeesian]

Hah yeah, whoops, caught in the act, lol. I can submit a PR to change them though. Don't let them be a showstopper (for longer-term sanity).