solver

Author: arnavk23

src/NLPModelsIpopt.jl

@@ -107,6 +107,27 @@ function SolverCore.reset!(solver::IpoptSolver, nlp::AbstractNLPModel)
   return problem
 end
 
+"""
+    solver = reset!(solver::IpoptSolver)
+
+Reset the `solver` state without changing the underlying problem.
+This resets the solver's internal state while keeping the same problem structure and callbacks.
+"""
+function SolverCore.reset!(solver::IpoptSolver)
+  problem = solver.problem
+  
+  # Reset solver state to initial values
+  problem.obj_val = Inf
+  problem.status = -1  # Use -1 to indicate not solved yet
+  problem.intermediate = nothing
+  
+  # Note: We keep the same problem structure, callbacks, and initial guess
+  # The user can call reset!(solver, nlp) if they want to change the problem
+  
+  # TODO: reset problem.ipopt_problem
+  return solver
+end
+
 """
     set_callbacks(nlp::AbstractNLPModel)
 

test/runtests.jl

@@ -115,4 +115,15 @@ end
 
   # Test that FeasibilityFormNLS is callable and returns the same object
   @test FeasibilityFormNLS(nls) === nls
+
+  # Test SolverCore.reset! method
+  nlp = ADNLPModel(x -> (x[1] - 1)^2 + (x[2] - 1)^2, [0.0, 0.0])
+  solver = IpoptSolver(nlp)
+  
+  # Test that reset! can be called without error
+  reset!(solver)
+  
+  # Test that we can solve after reset
+  result = solve!(solver, nlp, print_level=0)
+  @test result.status == :first_order
 end