Add module for Javascript target.

This module comes with a design that allows different code emitter implementations.
For the the phase of development the module is split into multiple files
which will be merged together when development converges.

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/branches/oliverb-javascript-v8@13737 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Source/Modules/javascript_emitter.h

@@ -0,0 +1,139 @@
+#ifndef JAVASCRIPT_EMITTER_H
+#define JAVASCRIPT_EMITTER_H
+
+#include "swigmod.h"
+
+/**
+ *  A class that wraps a code snippet used as template for code generation.
+ */
+class Template {
+    
+public:
+    Template(const String* code);
+    
+    ~Template();
+        
+    String* str();
+    
+    Template& Replace(const String* pattern, const String* repl);
+    
+private:
+    String* m_code;
+};
+
+class JSEmitter {
+
+public:
+    
+    enum JSEmitterType {
+        JavascriptCore,
+        V8,
+        QtScript
+    };    
+
+    JSEmitter();
+    
+    virtual ~JSEmitter();
+
+    /**
+     * Opens output files and temporary output DOHs.
+     */
+    virtual int Initialize(Node *n) = 0;
+    
+    /**
+     * Writes all collected code into the output file(s).
+     */
+    virtual int Dump(Node *n) = 0;
+    
+    /**
+     * Cleans up all open output DOHs.
+     */
+    virtual int Close() = 0;
+    
+    /**
+     * Switches the context for code generation.
+     * 
+     * Classes, global variables and global functions may need to
+     * be registered in certain static tables.
+     * This method should be used to switch output DOHs correspondingly.
+     */
+    virtual int SwitchContext(Node *n) { return SWIG_OK; };
+
+    /**
+     * Invoked at the beginning of the classHandler.
+     */
+    virtual int EnterClass(Node *n) { return SWIG_OK; };
+    
+    /**
+     * Invoked at the end of the classHandler.
+     */
+    virtual int ExitClass(Node *n) { return SWIG_OK; };
+
+    /**
+     * Invoked at the beginning of the variableHandler.
+     */
+    virtual int EnterVariable(Node *n) { return SWIG_OK; };
+
+    /**
+     * Invoked at the end of the variableHandler.
+     */
+    virtual int ExitVariable(Node *n) { return SWIG_OK; };
+
+    /**
+     * Invoked at the beginning of the functionHandler.
+     */
+    virtual int EnterFunction(Node *n) { return SWIG_OK; };
+
+    /**
+     * Invoked at the end of the functionHandler.
+     */
+    virtual int ExitFunction(Node *n) { return SWIG_OK; };
+    
+    /**
+     * Invoked by functionWrapper callback after call to Language::functionWrapper.
+     */
+    virtual int EmitWrapperFunction(Node *n);
+    
+    /**
+     * Registers a given code snippet for a given key name.
+     * 
+     * This method is called by the fragmentDirective handler
+     * of the JAVASCRIPT language module.
+     */
+    int RegisterTemplate(const String *name, const String *code);
+
+    /**
+     * Retrieve the code template registered for a given name.
+     */
+    const String* GetTemplate(const String *name);
+
+protected:
+    
+    virtual int EmitCtor(Node *n) = 0;
+    
+    virtual int EmitDtor(Node *n) = 0;
+
+    virtual int EmitFunction(Node *n, bool is_member) = 0;
+
+    virtual int EmitGetter(Node *n, bool is_member) = 0;
+
+    virtual int EmitSetter(Node *n, bool is_member) = 0;
+
+    bool IsSetterMethod(Node *n);
+
+    Node* GetBaseClass(Node *n);                            
+
+    const String* typemapLookup(Node *n, const_String_or_char_ptr tmap_method, 
+                            SwigType *type, int warning, Node *typemap_attributes = 0);
+    
+protected:
+
+    // empty string used at different places in the code
+    String *empty_string;
+    
+    Hash *templates;
+    
+    Wrapper* current_wrapper;
+};
+
+#endif // JAVASCRIPT_EMITTER_H