add char_decl_plugin

src/model/char_factory.h

@@ -0,0 +1,75 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    char_factory.h
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2011-14-11
+
+Revision History:
+
+--*/
+#pragma once
+
+#include "util/uint_set.h"
+#include "ast/char_decl_plugin.h"
+#include "ast/seq_decl_plugin.h"
+#include "model/model_core.h"
+#include "model/value_factory.h"
+
+class char_factory : public value_factory {
+    model_core&  m_model;
+    ast_manager& m;
+    seq_util     u;
+    uint_set     m_chars;
+    unsigned     m_next { 'A' };
+    expr_ref_vector m_trail;
+
+public:
+    
+    char_factory(ast_manager & m, family_id fid, model_core& md):
+        value_factory(m, fid),
+        m_model(md),
+        m(m),
+        u(m),
+        m_trail(m)
+    {
+    }
+        
+    expr* get_some_value(sort* s) override {
+        m_chars.insert('a');
+        return u.mk_char('a');
+    }
+
+    bool get_some_values(sort* s, expr_ref& v1, expr_ref& v2) override {
+        v1 = u.mk_char('a');
+        v2 = u.mk_char('b');
+        m_chars.insert('a');
+        m_chars.insert('b');
+        return true;
+    }
+
+    expr* get_fresh_value(sort* s) override {
+        while (m_chars.contains(m_next)) 
+            ++m_next;
+        if (m_next > u.max_char())
+            throw default_exception("Character range exhausted");
+        m_chars.insert(m_next);
+        return u.mk_char(m_next++);        
+    }
+
+    void register_value(expr* n) override {
+        unsigned ch;
+        if (u.is_const_char(n, ch)) 
+            m_chars.insert(ch);
+    }
+
+    void add_trail(expr* e) {
+        m_trail.push_back(e);
+    }    
+
+};
+