Print a constraint with Name #2335
Description
While building a model with Gurobi.jl and MOI, variable names is visiable from print(model), but constraint names are not. I think this is inconsistent.
julia> import MathOptInterface as MOI
julia> import Gurobi
julia> o = Gurobi.Optimizer();
julia> x = MOI.add_variable(o);
julia> ci = MOI.add_constraint(o, 1. * x, MOI.LessThan(0.))
MathOptInterface.ConstraintIndex{MathOptInterface.ScalarAffineFunction{Float64}, MathOptInterface.LessThan{Float64}}(1)
julia> print(o) ### model_print_1
Feasibility
Subject to:
ScalarAffineFunction{Float64}-in-LessThan{Float64}
0.0 + 1.0 v[1] <= 0.0
julia> MOI.set(o,MOI.VariableName(),x,"x") ### set Variable Name
julia> print(o) ### model_print_2
Feasibility
Subject to:
ScalarAffineFunction{Float64}-in-LessThan{Float64}
0.0 + 1.0 x <= 0.0 ### Variable Name updated from "v[1]" to "x", compared with model_print_1
julia> MOI.set(o,MOI.ConstraintName(),ci,"x_le_0") ### set Constraint Name
julia> print(o) ### model_print_3, which is the same as model_print_2
Feasibility
Subject to:
ScalarAffineFunction{Float64}-in-LessThan{Float64}
0.0 + 1.0 x <= 0.0
julia> I think an ideal case in model_print_3 should be something like
julia> print(o)
Feasibility
Subject to:
ScalarAffineFunction{Float64}-in-LessThan{Float64}
x_le_0: 0.0 + 1.0 x <= 0.0Do you think this is a good proposal, because when users model physical problems, they need to label constraints of different types (e.g., ramp_up rates, demand_balance,...)
It will be convenient to check them in the prints.
Or maybe this is a question with MOI, generally?
Thanks!