Add initial value setting for variables in Z3 API, solver, and optimize modules

src/api/api_opt.cpp

@@ -459,6 +459,21 @@ extern "C" {
         Z3_CATCH;
     }
 
-
+    void Z3_API Z3_optimize_set_initial_value(Z3_context c, Z3_optimize o, Z3_ast var, Z3_ast value) {
+        Z3_TRY;
+        LOG_Z3_optimize_set_initial_value(c, o, var, value);
+        RESET_ERROR_CODE();
+        if (to_expr(var)->get_sort() != to_expr(value)->get_sort()) {
+            SET_ERROR_CODE(Z3_INVALID_USAGE, "variable and value should have same sort");
+            return;
+        }
+        ast_manager& m = mk_c(c)->m();
+        if (!m.is_value(to_expr(value))) {
+            SET_ERROR_CODE(Z3_INVALID_USAGE, "a proper value was not supplied");
+            return;
+        }
+        to_optimize_ptr(o)->initialize_value(to_expr(var), to_expr(value));
+        Z3_CATCH;        
+    }
 
 };

src/api/api_solver.cpp

@@ -1143,5 +1143,23 @@ extern "C" {
         Z3_CATCH_RETURN(nullptr);
     }
 
+    void Z3_API Z3_solver_set_initial_value(Z3_context c, Z3_solver s, Z3_ast var, Z3_ast value) {
+        Z3_TRY;
+        LOG_Z3_solver_set_initial_value(c, s, var, value);
+        RESET_ERROR_CODE();
+        if (to_expr(var)->get_sort() != to_expr(value)->get_sort()) {
+            SET_ERROR_CODE(Z3_INVALID_USAGE, "variable and value should have same sort");
+            return;
+        }
+        ast_manager& m = mk_c(c)->m();
+        if (!m.is_value(to_expr(value))) {
+            SET_ERROR_CODE(Z3_INVALID_USAGE, "a proper value was not supplied");
+            return;
+        }
+        to_solver_ref(s)->user_propagate_initialize_value(to_expr(var), to_expr(value));
+        Z3_CATCH;        
+    }
+
+
 
 };

src/api/c++/z3++.h

@@ -2865,6 +2865,17 @@ namespace z3 {
             check_error(); 
             return result; 
         }
+        void set_initial_value(expr const& var, expr const& value) {
+            Z3_solver_set_initial_value(ctx(), m_solver, var, value);
+            check_error();
+        }
+        void set_initial_value(expr const& var, int i) {
+            set_initial_value(var, ctx().num_val(i, var.get_sort()));
+        }
+        void set_initial_value(expr const& var, bool b) {
+            set_initial_value(var, ctx().bool_val(b));            
+        }
+
         expr proof() const { Z3_ast r = Z3_solver_get_proof(ctx(), m_solver); check_error(); return expr(ctx(), r); }
         friend std::ostream & operator<<(std::ostream & out, solver const & s);
 
@@ -3330,6 +3341,17 @@ namespace z3 {
         handle add(expr const& e, unsigned weight) {
             return add_soft(e, weight);
         }
+        void set_initial_value(expr const& var, expr const& value) {
+            Z3_optimize_set_initial_value(ctx(), m_opt, var, value);
+            check_error();
+        }
+        void set_initial_value(expr const& var, int i) {
+            set_initial_value(var, ctx().num_val(i, var.get_sort()));
+        }
+        void set_initial_value(expr const& var, bool b) {
+            set_initial_value(var, ctx().bool_val(b));            
+        }
+
         handle maximize(expr const& e) {
             return handle(Z3_optimize_maximize(ctx(), m_opt, e));
         }

src/api/python/z3/z3.py

@@ -7353,6 +7353,13 @@ class Solver(Z3PPObject):
         Z3_solver_get_levels(self.ctx.ref(), self.solver, trail.vector, len(trail), levels)
         return trail, levels
 
+    def set_initial_value(self, var, value):
+        """initialize the solver's state by setting the initial value of var to value
+        """
+        s = var.sort()
+        value = s.cast(value)
+        Z3_solver_set_initial_value(self.ctx.ref(), self.solver, var.ast, value.ast)
+
     def trail(self):
         """Return trail of the solver state after a check() call.
         """
@@ -8032,6 +8039,13 @@ class Optimize(Z3PPObject):
             return [asoft(a) for a in arg]
         return asoft(arg)
 
+    def set_initial_value(self, var, value):
+        """initialize the solver's state by setting the initial value of var to value
+        """
+        s = var.sort()
+        value = s.cast(value)
+        Z3_optimize_set_initial_value(self.ctx.ref(), self.optimize, var.ast, value.ast)
+
     def maximize(self, arg):
         """Add objective function to maximize."""
         return OptimizeObjective(

src/api/z3_api.h

@@ -7241,6 +7241,18 @@ extern "C" {
 
     bool Z3_API Z3_solver_propagate_consequence(Z3_context c, Z3_solver_callback cb, unsigned num_fixed, Z3_ast const* fixed, unsigned num_eqs, Z3_ast const* eq_lhs, Z3_ast const* eq_rhs, Z3_ast conseq);
 
+
+    /**
+       \brief provide an initialization hint to the solver. The initialization hint is used to calibrate an initial value of the expression that
+       represents a variable. If the variable is Boolean, the initial phase is set according to \c value. If the variable is an integer or real,
+       the initial Simplex tableau is recalibrated to attempt to follow the value assignment.
+
+       def_API('Z3_solver_set_initial_value', VOID, (_in(CONTEXT), _in(SOLVER), _in(AST), _in(AST)))
+     */
+
+    void Z3_API Z3_solver_set_initial_value(Z3_context c, Z3_solver s, Z3_ast var, Z3_ast value);
+
+
     /**
        \brief Check whether the assertions in a given solver are consistent or not.
 

src/api/z3_optimization.h

@@ -139,6 +139,18 @@ extern "C" {
     */
     void Z3_API Z3_optimize_pop(Z3_context c, Z3_optimize d);
 
+    /**
+       \brief provide an initialization hint to the solver.
+       The initialization hint is used to calibrate an initial value of the expression that
+       represents a variable. If the variable is Boolean, the initial phase is set
+       according to \c value. If the variable is an integer or real,
+       the initial Simplex tableau is recalibrated to attempt to follow the value assignment.
+
+       def_API('Z3_optimize_set_initial_value', VOID, (_in(CONTEXT), _in(OPTIMIZE), _in(AST), _in(AST)))
+     */
+
+    void Z3_API Z3_optimize_set_initial_value(Z3_context c, Z3_optimize o, Z3_ast var, Z3_ast value);
+    
     /**
        \brief Check consistency and produce optimal values.
        \param c - context