add parameter to enable splitting guided by length constraints

src/smt/params/smt_params.h

@@ -26,6 +26,7 @@ Revision History:
 #include "smt/params/theory_array_params.h"
 #include "smt/params/theory_bv_params.h"
 #include "smt/params/theory_str_params.h"
+#include "smt/params/theory_seq_params.h"
 #include "smt/params/theory_pb_params.h"
 #include "smt/params/theory_datatype_params.h"
 #include "smt/params/preprocessor_params.h"
@@ -79,6 +80,7 @@ struct smt_params : public preprocessor_params,
                     public theory_array_params,
                     public theory_bv_params,
                     public theory_str_params,
+                    public theory_seq_params,
                     public theory_pb_params,
                     public theory_datatype_params {
     bool             m_display_proof;

src/smt/params/smt_params_helper.pyg

@@ -71,6 +71,7 @@ def_module_params(module_name='smt',
                           ('theory_case_split', BOOL, False, 'Allow the context to use heuristics involving theory case splits, which are a set of literals of which exactly one can be assigned True. If this option is false, the context will generate extra axioms to enforce this instead.'),
                           ('string_solver', SYMBOL, 'seq', 'solver for string/sequence theories. options are: \'z3str3\' (specialized string solver), \'seq\' (sequence solver), \'auto\' (use static features to choose best solver)'),
                           ('core.validate', BOOL, False, 'validate unsat core produced by SMT context'),
+                          ('seq.split_w_len', BOOL, True, 'enable splitting guided by length constraints'),
                           ('str.strong_arrangements', BOOL, True, 'assert equivalences instead of implications when generating string arrangement axioms'),
                           ('str.aggressive_length_testing', BOOL, False, 'prioritize testing concrete length values over generating more options'),
                           ('str.aggressive_value_testing', BOOL, False, 'prioritize testing concrete string constant values over generating more options'),

src/smt/params/theory_seq_params.cpp

@@ -0,0 +1,23 @@
+/*++
+Copyright (c) 2018 Microsoft Corporation
+
+Module Name:
+
+    theory_seq_params.cpp
+
+Abstract:
+
+    Parameters for sequence theory plugin
+
+Revision History:
+
+
+--*/
+
+#include "smt/params/theory_seq_params.h"
+#include "smt/params/smt_params_helper.hpp"
+
+void theory_seq_params::updt_params(params_ref const & _p) {
+    smt_params_helper p(_p);
+    m_split_w_len = p.seq_split_w_len();
+}

src/smt/params/theory_seq_params.h

@@ -0,0 +1,38 @@
+/*++
+Copyright (c) 2018 Microsoft Corporation
+
+Module Name:
+
+    theory_seq_params.h
+
+Abstract:
+
+    Parameters for sequence theory plugin
+
+Revision History:
+
+
+--*/
+
+#ifndef THEORY_SEQ_PARAMS_H
+#define THEORY_SEQ_PARAMS_H
+
+#include "util/params.h"
+
+struct theory_seq_params {
+    /*
+     * Enable splitting guided by length constraints
+     */
+    bool m_split_w_len;
+
+
+    theory_seq_params(params_ref const & p = params_ref()):
+        m_split_w_len(true)
+    {
+        updt_params(p);
+    }
+
+    void updt_params(params_ref const & p);
+};
+
+#endif /* THEORY_SEQ_PARAMS_H */