Fix TerminationStatus (#114)

* Fix TerminationStatus

* Add test

* Use nothing instead of a constant

Author: blegat

src/MOI_wrapper.jl

@@ -6,7 +6,7 @@ const VI = MOI.VariableIndex
 const MOIU = MOI.Utilities
 
 struct Solution
-    ret_val::Int
+    ret_val::Union{Nothing, Int}
     primal::Vector{Float64}
     dual_eq::Vector{Float64}
     dual_ineq::Vector{Float64}
@@ -16,8 +16,8 @@ struct Solution
     objective_constant::Float64
     solve_time::Float64
 end
-const OPTIMIZE_NOT_CALLED = -1
-Solution() = Solution(OPTIMIZE_NOT_CALLED, Float64[], Float64[], Float64[],
+# The values used by ECOS are from -7 to 10 so -10 should be safe
+Solution() = Solution(nothing, Float64[], Float64[], Float64[],
                       Float64[], NaN, NaN, NaN, NaN)
 
 # Used to build the data with allocate-load during `copy_to`.
@@ -287,7 +287,7 @@ MOI.get(optimizer::Optimizer, ::MOI.SolveTime) = optimizer.sol.solve_time
 function MOI.get(optimizer::Optimizer, ::MOI.RawStatusString)
     # Strings from https://github.com/ifa-ethz/ecos/blob/master/include/ecos.h
     flag = optimizer.sol.ret_val
-    if flag == OPTIMIZE_NOT_CALLED
+    if flag === nothing
         return "Optimize not called"
     elseif flag == ECOS_OPTIMAL
         return "Problem solved to optimality"
@@ -318,7 +318,7 @@ end
 # Implements getter for result value and statuses
 function MOI.get(optimizer::Optimizer, ::MOI.TerminationStatus)
     flag = optimizer.sol.ret_val
-    if flag == OPTIMIZE_NOT_CALLED
+    if flag === nothing
         return MOI.OPTIMIZE_NOT_CALLED
     elseif flag == ECOS.ECOS_OPTIMAL
         return MOI.OPTIMAL
@@ -327,15 +327,21 @@ function MOI.get(optimizer::Optimizer, ::MOI.TerminationStatus)
     elseif flag == ECOS.ECOS_DINF
         return MOI.DUAL_INFEASIBLE
     elseif flag == ECOS.ECOS_MAXIT
-        return MOI.IterationLimit
+        return MOI.ITERATION_LIMIT
+    elseif flag == ECOS.ECOS_NUMERICS || flag == ECOS.ECOS_OUTCONE
+        return MOI.NUMERICAL_ERROR
+    elseif flag == ECOS.ECOS_SIGINT
+        return MOI.INTERRUPTED
+    elseif flag == ECOS.ECOS_FATAL
+        return MOI.OTHER_ERROR
     elseif flag == ECOS.ECOS_OPTIMAL + ECOS.ECOS_INACC_OFFSET
         return MOI.ALMOST_OPTIMAL
     elseif flag == ECOS.ECOS_PINF + ECOS.ECOS_INACC_OFFSET
         return MOI.ALMOST_INFEASIBLE
     elseif flag == ECOS.ECOS_DINF + ECOS.ECOS_INACC_OFFSET
         return MOI.ALMOST_DUAL_INFEASIBLE
     else
-        return MOI.OTHER_ERROR
+        error("Unrecognized ECOS solve status flag: $flag.")
     end
 end
 

test/MOI_wrapper.jl

@@ -68,3 +68,33 @@ end
     @test MOI.get(model, MOI.RawParameter(:abstol)) ≈ 2e-5
     @test MOI.get(model, MOI.RawParameter("abstol")) == 2e-5
 end
+
+@testset "Iteration Limit" begin
+    # Problem data
+    v = [5.0, 3.0, 1.0]
+    w = [2.0, 1.5, 0.3]
+
+    MOI.empty!(bridged)
+
+    MOI.set(bridged, MOI.RawParameter("maxit"), 1)
+    MOI.set(bridged, MOI.Silent(), true)
+
+    x = MOI.add_variables(bridged, 3)
+    for xj in x
+        MOI.add_constraint(bridged, MOI.SingleVariable(xj), MOI.Interval(0.0, 1.0))
+    end
+
+    # Constraint
+    MOI.add_constraint(bridged, MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.(w, x), 0.0), MOI.LessThan(3.0))
+
+    # Set the objective
+    MOI.set(bridged,
+        MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(),
+        MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.(v, x), 0.0)
+    )
+    MOI.set(bridged, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+
+    MOI.optimize!(bridged)
+
+    @test MOI.get(bridged, MOI.TerminationStatus()) == MOI.ITERATION_LIMIT
+end