Reorganizing code base

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/ast/used_vars.h

@@ -0,0 +1,59 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    used_vars.h
+
+Abstract:
+
+    Functor used to collect the set of used variables.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2008-01-14.
+
+Revision History:
+
+--*/
+#ifndef _USED_VARS_H_
+#define _USED_VARS_H_
+
+#include"ast.h"
+#include"expr_delta_pair.h"
+
+class used_vars {
+    ptr_vector<sort> m_found_vars;
+    typedef hashtable<expr_delta_pair, obj_hash<expr_delta_pair>, default_eq<expr_delta_pair> > cache;
+    cache                    m_cache;
+    svector<expr_delta_pair> m_todo;
+
+    void process(expr * n, unsigned delta);
+
+public:
+    
+    void operator()(expr * n) {
+        m_found_vars.reset();
+        process(n, 0);
+    }
+
+    void reset() {
+        m_found_vars.reset();
+    }
+
+    void process(expr * n) {
+        process(n, 0);
+    }
+
+    unsigned get_max_found_var_idx_plus_1() const { return m_found_vars.size(); }
+
+    sort * get(unsigned var_idx) const { return m_found_vars[var_idx]; }
+    sort * contains(unsigned var_idx) const { return var_idx < m_found_vars.size() ? m_found_vars[var_idx] : 0; }
+    
+    bool uses_all_vars(unsigned num_decls) const;
+    bool uses_a_var(unsigned num_decls) const;
+    unsigned get_num_vars() const;
+};
+
+#endif /* _USED_VARS_H_ */
+