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More Occam's Razor C to Java Translator Theory of Morality II


Simulating the Elisp dynamic scoping mechanism in C++ Free Stuff

Abstract

To add dynamic scoping to C++, the C++ equivalent of Elisp's "unwind-protect" and Java's "finally" mechanism needs to be used. In the absence of exceptions this is very simple to code:

int global;

void foo()
{
    int global_temp = global;
    global = new_value;

    /* rest of foo method */

    global = global_temp;
}

In the case that exceptions are used then destructors must be used, using a design pattern that C++ creator Bjarne Stroustrup calls Resource Acquisition Is Initialization (or R.A.I.I. for short). An alternative approach to this one is to prefer to use C++ preprocessor macro calls to ordinary function/method calls. Here is an example where the F3 and F4 macro functions can access the variable x from the function f1.

#define F4 \
call_other_1(x);  \

#define F3 \
call_other_2(x)   \

#define F2 \
F3();         \
F4();         \

void f1()
{
   int x;
   F2();
}
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| Main Menu | Research Projects | Photo Album | Curriculum Vitae | The Greatest Artists |
| Email Address | Computer Games | Web Design | Java Training Wheels | The Fly (A Story) |
| Political Activism | Scruff the Cat | My Life Story | Smoking Cessation | Other Links |
| Debugging Macros | String Class I | Linked List System I | Java for C Programmers | Naming Convention |
| String Class II | How I use m4 | Strings III | Symmetrical I/O | Linked Lists II |
| Run-Time Type Info | Virtual Methods | An Array System | Science & Religion | Submodes |
| Nested Packages | Memory Leaks | Garbage Collection | Internet & Poverty | What is Knowledge? |
| Limits of Evolution | Emacs Additions | Function Plotter | Romantic Love | The Next Big Thing |
| Science Fiction | Faster Compilation | Theory of Morality | Elisp Scoping | Elisp Advice |
| S.O.G.M. Pattern | Safe Properties | School Bullying | Charisma Control | Life and Death |
| Splitting Java | Multiple Ctors | Religious Beliefs | Conversation 1 | Conversation 2 |
| J.T.W. Language | Emacs Additions II | Build Counter | Relation Plotter | Lisp++ Language |
| Memory Leaks II | Super Constructors | CRUD Implementation | Order a Website Form | There Is An Afterlife |
| More Occam's Razor | C to Java Translator | Theory of Morality II
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