[gnumeric] nlsolve: simplify code.

[Morten Welinder <mortenw src gnome org>]

commit 1f0fb574464ae86e983fee32ce9bcb32972e49f7
Author: Morten Welinder <terra gnome org>
Date:   Fri May 8 21:29:04 2015 -0400

    nlsolve: simplify code.
    
    Use the precomputed discrete flags and variable limits.

 plugins/nlsolve/ChangeLog     |    4 ++++
 plugins/nlsolve/gnm-nlsolve.c |   28 ++++++++++++++++++++--------
 2 files changed, 24 insertions(+), 8 deletions(-)
---
diff --git a/plugins/nlsolve/ChangeLog b/plugins/nlsolve/ChangeLog
index 60ee4fa..5143113 100644
--- a/plugins/nlsolve/ChangeLog
+++ b/plugins/nlsolve/ChangeLog
@@ -1,3 +1,7 @@
+2015-05-08  Morten Welinder  <terra gnome org>
+
+       * gnm-nlsolve.c (check_program): Simplify.
+
 2015-05-06  Morten Welinder  <terra gnome org>
 
        * gnm-nlsolve.c (check_program): We really don't handle equality
diff --git a/plugins/nlsolve/gnm-nlsolve.c b/plugins/nlsolve/gnm-nlsolve.c
index 7c31ba8..cbcbf40 100644
--- a/plugins/nlsolve/gnm-nlsolve.c
+++ b/plugins/nlsolve/gnm-nlsolve.c
@@ -59,26 +59,38 @@ typedef struct {
 } GnmNlsolve;
 
 static gboolean
-check_program (const GnmSolverParameters *params, GError **err)
+check_program (GnmSolver *sol, GError **err)
 {
+       unsigned ui;
+       const GnmSolverParameters *params = sol->params;
        GSList *l;
 
-       if (params->options.assume_discrete)
-               goto no_discrete;
-
        for (l = params->constraints; l; l = l->next) {
                GnmSolverConstraint *c  = l->data;
                switch (c->type) {
-               case GNM_SOLVER_INTEGER:
-               case GNM_SOLVER_BOOLEAN:
-                       goto no_discrete;
                case GNM_SOLVER_EQ:
+                       /*
+                        * This catches also equalities where the sides are not
+                        * input variables.
+                        */
                        goto no_equal;
                default:
                        break;
                }
        }
 
+       for (ui = 0; ui < sol->input_cells->len; ui++) {
+               if (sol->discrete[ui])
+                       goto no_discrete;
+
+               /*
+                * This also catches using two inequality constraints used
+                * to emulate equality.
+                */
+               if (sol->min[ui] == sol->max[ui])
+                       goto no_equal;
+       }
+
        return TRUE;
 
 no_discrete:
@@ -154,7 +166,7 @@ gnm_nlsolve_prepare (GnmSolver *sol, WorkbookControl *wbc, GError **err,
 
        gnm_solver_set_status (sol, GNM_SOLVER_STATUS_PREPARING);
 
-       ok = check_program (sol->params, err);
+       ok = check_program (sol, err);
        if (ok)
                ok = gnm_iter_solver_get_initial_solution (nl->isol, err);