Feature request: modifying a constraint

[tambysatya]

Hello !

Thanks a lot for your library ! It is very useful for my project. Unfortunately, a feature is missing which makes me struggle to complete my code. For this reason, I was wondering if it is possible for you to add a feature to modify a constraint.

I don't really know GLPK, but in cplex we have access to a function which can modify the linear coefficient of a variable. In Haskell, it would look like (specialized for Glpk):

setLinearCoef :: Constraint -> Variable -> Double -> Glpk ()

Do you think it is possible to add it in your framework ? Otherwise, if I understood correctly, we need to delete then recreate a new constraint which can be difficult when building a model from a complicated data structure. This can also be very helpful when we need to successively solve a sequence of models that only differ slightly.

I also strongly envisage to port Cplex using your framework at some point.

Thank you for your help !

Best,
Satya