MIP solution status

Here is a piece of Mosel code that captures all values for MIPSTATUS in a similar way as your example:

 case getparam("XPRS_MIPSTATUS") of
   XPRS_MIP_NOT_LOADED: status:="Problem has not been loaded"
   XPRS_MIP_LP_NOT_OPTIMAL: status:="MIP search incomplete - LP not solved, no integer solution"
   XPRS_MIP_LP_OPTIMAL: status:="MIP search incomplete - LP solved, no integer solution"
   XPRS_MIP_NO_SOL_FOUND: status:="MIP search incomplete - no integer solution"
   XPRS_MIP_SOLUTION: status:="MIP search incomplete - integer solution found"
   XPRS_MIP_INFEAS: status:="MIP search complete - no integer solution found"
   XPRS_MIP_OPTIMAL: status:="MIP search complete - integer solution found"
   XPRS_MIP_UNBOUNDED: status:="MIP search incomplete - initial continuous relaxation is unbounded"
   else status:="Unkonwn status value"
 end-case 

Status information provided through MIPSTATUS, LPSTATUS etc depends on the problem type that is being solved, whereas the more recently introduced generic status values SOLVESTATUS and SOLSTATUS work with all problem types supported by Xpress Solver, similarly to Mosel's 'getprobstat'. Here is another piece of Mosel code to show their possible values and meaning:

 declarations
   SolStat, SolvStat: array(integer) of string    ! Status messages
 end-declarations
 
 SolvStat:: ([XPRS_SOLVESTATUS_UNSTARTED, XPRS_SOLVESTATUS_STOPPED, 
   XPRS_SOLVESTATUS_FAILED, XPRS_SOLVESTATUS_COMPLETED])  
  ["The solve has not been started.", "Optimization has been interrupted.",
   "Optimization has run into a nonrecoverable problem and failed.",
   "Search completed."] 
 
 SolStat:: ([XPRS_SOLSTATUS_NOTFOUND, XPRS_SOLSTATUS_OPTIMAL, 
   XPRS_SOLSTATUS_FEASIBLE, XPRS_SOLSTATUS_INFEASIBLE, XPRS_SOLSTATUS_UNBOUNDED])
  ["No solution available.", "An optimal solution has been found.",
   "A solution that is not proven optimal is found.",
   "No solution exists.", "The problem is unbounded, if feasible."]
 
 writeln("Problem solve status: ", SolvStat(getparam("XPRS_SOLVESTATUS")), 
         " Solution status: ", SolStat(getparam("XPRS_SOLSTATUS")))