added compiler extensions class

components/compiler/context.hpp

@@ -3,14 +3,23 @@
 
 namespace Compiler
 {
+    class Extensions;
+
     class Context
     {
+            const Extensions *mExtensions;
+            
         public:
         
+            Context() : mExtensions (0) {}
+        
             virtual ~Context() {}
             
             virtual bool canDeclareLocals() const = 0;
             ///< Is the compiler allowed to declare local variables?
+            
+            void setExtensions (const Extensions *extensions = 0);
+            ///< Set compiler extensions.
     };
 }
 

components/compiler/extensions.cpp

@@ -0,0 +1,18 @@
+
+#include "extensions.hpp"
+
+namespace Compiler
+{
+
+    Extensions::Extensions() : mNextKeywordIndex (-1) {}
+
+    int Extensions::searchKeyword (const std::string& keyword) const
+    {
+        std::map<std::string, int>::const_iterator iter = mKeywords.find (keyword);
+        
+        if (iter==mKeywords.end())
+            return 0;
+            
+        return iter->second;
+    }
+}

components/compiler/extensions.hpp

@@ -0,0 +1,28 @@
+#ifndef COMPILER_EXTENSIONS_H_INCLUDED
+#define COMPILER_EXTENSINOS_H_INCLUDED
+
+#include <string>
+#include <map>
+
+namespace Compiler
+{
+    /// \brief Collection of compiler extensions
+    
+    class Extensions
+    {
+            int mNextKeywordIndex;
+            std::map<std::string, int> mKeywords;
+    
+        public:
+    
+            Extensions();
+    
+            int searchKeyword (const std::string& keyword) const;
+            ///< Return extension keyword code, that is assigned to the string \a keyword.
+            /// - if no match is found 0 is returned.
+            /// - keyword must be all lower case.
+    };
+}
+
+#endif
+

components/compiler/scanner.cpp

@@ -9,6 +9,7 @@
 #include "exception.hpp"
 #include "errorhandler.hpp"
 #include "parser.hpp"
+#include "extensions.hpp"
 
 namespace Compiler
 {
@@ -271,8 +272,22 @@ namespace Compiler
             if (lowerCase==keywords[i])
                 break;
 
-        cont =
-            keywords[i] ? parser.parseKeyword (i, loc, *this) : parser.parseName (name, loc, *this);
+        if (keywords[i])
+        {
+            cont = parser.parseKeyword (i, loc, *this);
+            return true;
+        }
+        
+        if (mExtensions)
+        {
+            if (int keyword = mExtensions->searchKeyword (lowerCase))
+            {
+                cont = parser.parseKeyword (keyword, loc, *this);
+                return true;            
+            }
+        }
+
+        cont = parser.parseName (name, loc, *this);
 
         return true;
     }
@@ -445,8 +460,10 @@ namespace Compiler
 
     // constructor
 
-    Scanner::Scanner (ErrorHandler& errorHandler, std::istream& inputStream)
-    : mErrorHandler (errorHandler), mStream (inputStream), mPutback (Putback_None)
+    Scanner::Scanner (ErrorHandler& errorHandler, std::istream& inputStream,
+        const Extensions *extensions)
+    : mErrorHandler (errorHandler), mStream (inputStream), mExtensions (extensions),
+      mPutback (Putback_None)
     {
     }
 

components/compiler/scanner.hpp

@@ -10,6 +10,7 @@ namespace Compiler
 {
     class ErrorHandler;
     class Parser;
+    class Extensions;
 
     /// \brief Scanner
     ///
@@ -28,6 +29,7 @@ namespace Compiler
             TokenLoc mLoc;
             TokenLoc mPrevLoc;
             std::istream& mStream;
+            const Extensions *mExtensions;
             putback_type mPutback;
             int mPutbackCode;
             int mPutbackInteger;
@@ -86,7 +88,8 @@ namespace Compiler
 
         public:
 
-            Scanner (ErrorHandler& errorHandler, std::istream& inputStream);
+            Scanner (ErrorHandler& errorHandler, std::istream& inputStream,
+                const Extensions *extensions = 0);
 		    ///< constructor
 
             void scan (Parser& parser);