initial stab at new bv-sls based on repair actions

src/ast/sls/bv_sls.h

@@ -0,0 +1,99 @@
+/*++
+Copyright (c) 2024 Microsoft Corporation
+
+Module Name:
+
+    bv_sls.h
+
+Abstract:
+
+    A Stochastic Local Search (SLS) engine
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2024-02-07
+    
+--*/
+#pragma once
+
+#include "util/lbool.h"
+#include "util/params.h"
+#include "util/scoped_ptr_vector.h"
+#include "util/uint_set.h"
+#include "ast/ast.h"
+#include "ast/sls/sls_stats.h"
+#include "ast/sls/sls_powers.h"
+#include "ast/sls/sls_valuation.h"
+#include "ast/sls/bv_sls_terms.h"
+#include "ast/sls/bv_sls_eval.h"
+#include "ast/bv_decl_plugin.h"
+#include "model/model.h"
+
+namespace bv {
+
+
+    class sls {
+
+        struct config {
+            unsigned    m_max_restarts = 1000;
+            unsigned    m_max_repairs = 100000;
+        };
+
+        ast_manager&        m;
+        bv_util             bv;
+        sls_terms           m_terms;
+        sls_eval            m_eval;
+        sls_stats           m_stats;
+        indexed_uint_set    m_repair_down, m_repair_up;
+        ptr_vector<expr>    m_todo;
+        random_gen          m_rand;
+        config              m_config;
+        
+        
+        bool eval_is_correct(app* e);
+        bool try_repair_down(app* e);
+        bool try_repair_up(app* e);
+
+        bool try_repair_down(app* e, unsigned i);
+
+    public:
+        sls(ast_manager& m);
+                
+        /**
+        * Add constraints
+        */
+        void assert_expr(expr* e) { m_terms.assert_expr(e); }
+
+        /*
+        * Invoke init after all expressions are asserted. 
+        * No other expressions can be asserted after init.
+        */
+        void init();
+
+        /**
+        * Invoke init_eval to initialize, or re-initialize, values of
+        * uninterpreted constants.
+        */
+        void init_eval(std::function<bool(expr*, unsigned)>& eval);
+
+        /**
+        * Run (bounded) local search to find feasible assignments.
+        */
+        lbool operator()();
+
+        void updt_params(params_ref const& p) {}
+        void collect_statistics(statistics & st) const { m_stats.collect_statistics(st); }
+        void reset_statistics() { m_stats.reset(); }
+
+        sls_stats const& get_stats() const { return m_stats; }
+
+        std::ostream& display(std::ostream& out);
+
+        /**
+        * Retrieve valuation
+        */
+        sls_valuation const& wval(expr* e) const { return m_eval.wval0(e); }
+
+        model_ref get_model();
+    };
+}