@NLconstraint names

[hdavid16]

It's great to see that names (with indexing) can now be assigned to nonlinear constraints. The following features would be nice to have:

• extend the @NLconstraint macro to allow the base_name kwarg as is the case in @constraint.
• extend JuMP.name to allow accessing the name of the nonlinear constraint.
• extend JuMP.set_name for nonlinear constraints.

[odow]

This is related to the MOI Nonlinear redesign. At the moment, nonlinear constraints don't exist as first-class objects, so they don't support the MOI.ConstraintName attribute, and therefore JuMP can't set their name.

So implementing this would first require jump-dev/MathOptInterface.jl#846

[odow]

I'm going to close this as won't-fix for now. Nonlinear constraints don't have names. If/when we update MOI to have first-class nonlinear constraints, this is something that will happen naturally.

[hdavid16]

They do appear to have names now...

using JuMP
m=Model()
@variable(m,x);
@NLconstraint(m, constraint_1, exp(x) <= 1)
#exp(x) - 1.0 <= 0
m[:constraint_1]
#exp(x) - 1.0 <= 0

[odow]

They have a symbolic identifier, but not a MOI.ConstraintName. The distinction is somewhat subtle:
https://jump.dev/JuMP.jl/stable/manual/constraints/#String-names,-symbolic-names,-and-bindings

JuMP.name is syntactic sugar for get/set of MOI.ConstraintName. There is no mechanism in JuMP or MOI for nonlinear constraints to store a String as the constraint, and you cannot look up a nonlinear constraint by a String name.

I think what you're asking for in DisjunctiveProgramming is a way to look up if a constraint has been stored in the object_dictionary, but that is orthogonal to the name discussion.

[hdavid16]

ok. makes sense. Thanks for clarifying.