New function to retrieve polarity value of a variable.

src/sat/satoko/solver.c

@@ -195,7 +195,7 @@ static inline unsigned solver_decide(solver_t *s)
         if (solver_has_marks(s) && !var_mark(s, next_var))
             next_var = UNDEF;
     }
-    return var2lit(next_var, vec_char_at(s->polarity, next_var));
+    return var2lit(next_var, var_polarity(s, next_var));
 }
 
 static inline void solver_new_decision(solver_t *s, unsigned lit)

src/sat/satoko/solver.h

@@ -132,6 +132,11 @@ static inline char var_value(solver_t *s, unsigned var)
     return vec_char_at(s->assigns, var);
 }
 
+static inline char var_polarity(solver_t *s, unsigned var)
+{
+    return vec_char_at(s->polarity, var);
+}
+
 static inline unsigned var_dlevel(solver_t *s, unsigned var)
 {
     return vec_uint_at(s->levels, var);