shadow->proxy terminology update

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@10400 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/python/exceptproxy/Makefile

@@ -1,6 +1,6 @@
 TOP        = ../..
 SWIG       = $(TOP)/../preinst-swig
-CXXSRCS    = example.cxx
+CXXSRCS    = 
 TARGET     = example
 INTERFACE  = example.i
 LIBS       = -lm

Examples/python/exceptproxy/example.h

@@ -0,0 +1,54 @@
+/* File : example.h */
+
+// A simple exception
+class EmptyError { };
+class FullError { 
+ public:
+  int maxsize;
+  FullError(int m) : maxsize(m) { }
+};
+
+#if defined(_MSC_VER)
+  #pragma warning(disable: 4290) // C++ exception specification ignored except to indicate a function is not __declspec(nothrow)
+#endif
+
+template<typename T> class Queue {
+  int maxsize;
+  T   *items;
+  int nitems;
+  int last;
+ public: 
+  Queue(int size) {
+    maxsize = size;
+    items = new T[size];
+    nitems = 0;
+    last = 0;
+  }
+  ~Queue() {
+    delete [] items;
+  }
+  void enqueue(T x) throw(FullError) {
+    if (nitems == maxsize) {
+      throw FullError(maxsize);
+    }
+    items[last] = x;
+    last = (last + 1) % maxsize;
+    nitems++;
+  }
+  T dequeue()  {
+    T x;
+    if (nitems == 0) throw EmptyError();
+    x = items[(last + maxsize - nitems) % maxsize];
+    nitems--;
+    return x;
+  }
+  int length() {
+    return nitems;
+  }
+};
+
+
+#if defined(_MSC_VER)
+  #pragma warning(default: 4290) // C++ exception specification ignored except to indicate a function is not __declspec(nothrow)
+#endif
+

Examples/python/exceptproxy/example.i

@@ -0,0 +1,114 @@
+/* This is a rather sophisticated example that illustrates exception handling,
+   templates, and proxy classes. 
+
+   (i) The %exception directive is used to attach exception handlers
+       to specific methods.
+
+   (ii) Exception classes are automatically converted to proxy class
+       objects.
+
+   (iii) The %template directive is used to expand the templates
+*/
+
+%module example
+
+%{
+#include "example.h"
+%}
+
+/* Define some exception handlers for specific methods.   In
+   the header file, the enqueue method throws FullError and
+   the dequeue method throws EmptyError.  Since we don't
+   want to define an exception handler for everything, we
+   simply write a handler each method individually.
+
+   Note: the *::enqueue syntax means that we simply define
+   the handler for any class with this method defined.
+*/
+
+/*
+  First we need to 'disable' the default swig throw mechanism for the
+  FullError class. We do this by rethrowing the exception.
+
+  Note that this is necessary since the class appears in a throw
+  declaration:
+
+
+    void enqueue(T x) throw(FullError);
+
+  hence, swig recognizes it as an exception class and it will generate
+  the necessary code to catch it and rethrow it to the python side.
+   
+*/
+%typemap(throws) FullError "(void)$1; throw;";
+
+
+%exception *::enqueue {
+   try {
+      $action
+   } catch(FullError& e) {
+     FullError *ecopy = new FullError(e);
+     PyObject *err = SWIG_NewPointerObj(ecopy, SWIGTYPE_p_FullError, 1);
+     PyErr_SetObject(SWIG_Python_ExceptionType(SWIGTYPE_p_FullError), err);
+     SWIG_fail;
+   }
+}
+
+/* Some notes about the code above:
+
+   (0) $action gets replaced with the actual method call.
+
+   (1) We are going to return a copy of the exception object (FullError)
+       to pass back to the Python interpreter.  This is why the copy
+       constructor is being called.
+
+   (2) The SWIG_NewPointerObj() call automatically wraps the exception object
+       into a proxy class.  The SWIGTYPE_p_FullError is the type-descriptor
+       used for type checking.  The "1" indicates that Python will have
+       ownership of the resulting object.
+
+   (3) The PyErr_SetObject call sets the Python exception.  However,
+       the SWIGTYPE_p_FullError->clientdata reference may not be
+       obvious.  This is actually the Python proxy class object
+       for FullError.  Recall that in Python, exceptions are defined
+       as classes.  Therefore, this works perfectly as the argument to
+       PyErr_SetObject()!   A neat trick perhaps.
+*/
+
+/*
+  Now, the EmpytError doesn't appear in a throw declaration, and hence
+  we need to 'mark' it as an exception class. In python, classes that 
+  are used as exception are 'special', and need to be wrapped as
+  'classic' ones.
+
+  This is a python issue, and if you don't mark the class, you will
+  see 'interesting' behaviours at the python side.
+  
+
+*/
+%exceptionclass EmptyError;
+%exceptionclass FullError;
+
+%exception *::dequeue {
+   try {
+      $action
+   } catch(EmptyError& e) {
+      EmptyError *ecopy = new EmptyError(e);
+      PyObject *err = SWIG_NewPointerObj(ecopy, SWIGTYPE_p_EmptyError, 1);
+      PyErr_SetObject(SWIG_Python_ExceptionType(SWIGTYPE_p_EmptyError), err);
+      SWIG_fail;
+   }
+}
+
+/* Grab the original header file */
+%include "example.h"
+
+/* Instantiate a few templates */
+
+%template(intQueue) Queue<int>;
+%template(doubleQueue) Queue<double>;
+
+
+
+
+

Examples/python/exceptproxy/runme.py

@@ -0,0 +1,45 @@
+# file: runme.py
+import example
+
+q = example.intQueue(10)
+
+print "Inserting items into intQueue"
+
+try:
+      for i in range(0,100):
+            q.enqueue(i)
+except example.FullError,e:
+      print "Maxsize is", e.maxsize
+
+print "Removing items"
+
+try:
+      while 1:
+            q.dequeue()
+except example.EmptyError,e:
+      pass
+
+
+q = example.doubleQueue(1000)
+
+print "Inserting items into doubleQueue"
+
+try:
+      for i in range(0,10000):
+            q.enqueue(i*1.5)
+except example.FullError,e:
+      print "Maxsize is", e.maxsize
+
+print "Removing items"
+
+try:
+      while 1:
+            q.dequeue()
+except example.EmptyError,e:
+      pass
+
+
+
+
+
+      

Examples/python/shadow/example.cxx

@@ -1,31 +0,0 @@
-/* File : example.c */
-
-#include "example.h"
-#include <math.h>
-#ifndef M_PI
-#  define M_PI 3.14159265358979323846
-#endif
-
-/* Move the shape to a new location */
-void Shape::move(double dx, double dy) {
-  x += dx;
-  y += dy;
-}
-
-int Shape::nshapes = 0;
-
-double Circle::area() {
-  return M_PI*radius*radius;
-}
-
-double Circle::perimeter() {
-  return 2*M_PI*radius;
-}
-
-double Square::area() {
-  return width*width;
-}
-
-double Square::perimeter() {
-  return 4*width;
-}

Examples/python/shadow/example.h

@@ -1,39 +0,0 @@
-/* File : example.h */
-
-class Shape {
-public:
-  Shape() {
-    nshapes++;
-  }
-  virtual ~Shape() {
-    nshapes--;
-  };
-  double  x, y;   
-  void    move(double dx, double dy);
-  virtual double area() = 0;
-  virtual double perimeter() = 0;
-  static  int nshapes;
-};
-
-class Circle : public Shape {
-private:
-  double radius;
-public:
-  Circle(double r) : radius(r) { };
-  virtual double area();
-  virtual double perimeter();
-};
-  
-class Square : public Shape {
-private:
-  double width;
-public:
-  Square(double w) : width(w) { };
-  virtual double area();
-  virtual double perimeter();
-};
-
-
-
-
-  

Examples/python/shadow/example.i

@@ -1,10 +0,0 @@
-/* File : example.i */
-%module example
-
-%{
-#include "example.h"
-%}
-
-/* Let's just grab the original header file here */
-%include "example.h"
-

Examples/python/shadow/index.html

@@ -1,19 +0,0 @@
-<html>
-<head>
-<title>SWIG:Examples:python:proxy</title>
-</head>
-
-<body bgcolor="#ffffff">
-
-
-<tt>SWIG/Examples/python/proxy/</tt>
-<hr>
-
-<H2>Wrapping a simple C++ class</H2>
-
-<p>
-This example illustrates the wrapping of some C++ classes by proxy classes.
-
-<hr>
-</body>
-</html>

Examples/python/shadow/runme.py

@@ -1,51 +0,0 @@
-# file: runme.py
-
-# This file illustrates the proxy class C++ interface generated
-# by SWIG.
-
-import example 
-
-# ----- Object creation -----
-
-print "Creating some objects:"
-c = example.Circle(10)
-print "    Created circle", c
-s = example.Square(10)
-print "    Created square", s
-
-# ----- Access a static member -----
-
-print "\nA total of", example.cvar.Shape_nshapes,"shapes were created"
-
-# ----- Member data access -----
-
-# Set the location of the object
-
-c.x = 20
-c.y = 30
-
-s.x = -10
-s.y = 5
-
-print "\nHere is their current position:"
-print "    Circle = (%f, %f)" % (c.x,c.y)
-print "    Square = (%f, %f)" % (s.x,s.y)
-
-# ----- Call some methods -----
-
-print "\nHere are some properties of the shapes:"
-for o in [c,s]:
-      print "   ", o
-      print "        area      = ", o.area()
-      print "        perimeter = ", o.perimeter()
-
-print "\nGuess I'll clean up now"
-
-# Note: this invokes the virtual destructor
-del c
-del s
-
-s = 3
-print example.cvar.Shape_nshapes,"shapes remain"
-print "Goodbye"
-