--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/util/symtable.hh	Wed Jan 31 15:32:38 2007 +0100
@@ -0,0 +1,121 @@
+/*
+ * (c) 2003 Mario de Sousa
+ *
+ * Offered to the public under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * This code is made available on the understanding that it will not be
+ * used in safety-critical situations without a full and competent review.
+ */
+
+/*
+ * An IEC 61131-3 IL and ST compiler.
+ *
+ * Based on the
+ * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
+ *
+ */
+
+
+/*
+ * A generic symbol table.
+ *
+ * This is used to create symbol tables such as a list of
+ * variables currently in scope, a list of previously defined
+ * functions, etc...
+ */
+
+
+
+#ifndef _SYMTABLE_HH
+#define _SYMTABLE_HH
+
+#include "../absyntax/absyntax.hh"
+
+#include <map>
+#include <string>
+
+
+
+
+template<typename value_type, value_type null_value> class symtable_c {
+  /* Case insensitive string compare copied from
+   * "The C++ Programming Language" - 3rd Edition
+   * by Bjarne Stroustrup, ISBN 0201889544.
+   */
+  class nocase_c {
+    public:
+      bool operator() (const std::string& x, const std::string& y) const {
+        std::string::const_iterator ix = x.begin();
+        std::string::const_iterator iy = y.begin();
+
+        for(; (ix != x.end()) && (iy != y.end()) && (toupper(*ix) == toupper(*iy)); ++ix, ++iy);
+        if (ix == x.end()) return (iy != y.end());
+        if (iy == y.end()) return false;
+        return (toupper(*ix) < toupper(*iy));
+      };
+  };
+
+  public:
+    typedef value_type value_t;
+
+  private:
+    /* Comparison between identifiers must ignore case, therefore the use of nocase_c */
+    typedef std::map<std::string, value_t, nocase_c> base_t;
+    base_t _base;
+
+  public:
+  typedef typename base_t::iterator iterator;
+  typedef typename base_t::const_iterator const_iterator;
+  typedef typename base_t::reverse_iterator reverse_iterator;
+  typedef typename base_t::const_reverse_iterator const_reverse_iterator;
+
+  private:
+      /* pointer to symbol table of the next inner scope */
+    symtable_c *inner_scope;
+    void reset(void); /* clear all entries... */
+
+  public:
+    symtable_c(void);
+
+    void push(void); /* create new inner scope */
+    int  pop(void);  /* clear most inner scope */
+
+    void set(const char *identifier_str, value_t value);
+    void set(const symbol_c *symbol, value_t value);
+    void insert(const char *identifier_str, value_t value);
+    void insert(const symbol_c *symbol, value_t value);
+
+    /* Search for an entry. Will return end_value() if not found */
+    value_t end_value(void) {return null_value;}
+    value_t find_value(const char *identifier_str);
+    value_t find_value(const symbol_c *symbol);
+
+    iterator find(const char *identifier_str) {return _base.find(identifier_str);}
+
+  /* iterators pointing to beg/end of map... */
+    iterator begin() 			{return _base.begin();}
+    const_iterator begin() const	{return _base.begin();}
+    iterator end()			{return _base.end();}
+    const_iterator end() const 		{return _base.end();}
+    reverse_iterator rbegin()		{return _base.rbegin();}
+    const_reverse_iterator rbegin() const {return _base.rbegin();}
+    reverse_iterator rend() 		{return _base.rend();}
+    const_reverse_iterator rend() const	{return _base.rend();}
+
+    /* debuging function... */
+    void print(void);
+};
+
+
+
+/* Templates must include the source into the code! */
+#include "symtable.cc"
+
+#endif /*  _SYMTABLE_HH */