Classy

A simple framework for object-oriented programming in C

Just a small project I've been working on to use object-oriented programming principles in C. The syntax and internal workings are roughly modeled after Objective-C, but obviously more lightweight.

I hated how the only way for me to use classes was either to:

Use structs and function pointers, and call with a class->function(args) format
Use C++ (!?)

I basically am just using various macros to achieve the first option, but without all the boilerplate.

This actually doesn't follow many of the basic programming principles of OO programming, but I think it's still a cool project.

Creating a Class:

2 files are used for class creation, a header (.h) and a class (.c) file

The Header File:

In the header file, the class's instance variables and methods are encased between two keywords

    classHead(className) 
    
    ***IVARS AND FUNCTIONS GO HERE***
    
    endHead(className)

Within this interface, instance variables are declared using traditional C syntax, and methods are created as so:

    varType varName
    m_func(className, functionName, args)

Then, outside the interface, methods must again be declared with and then with the syntax

    func(className, functionName, args)

Example myClass.h

classHead(myClass)
  int myIvar;
  void m_func(myClass, myFunction, int arg1, String *arg2, boolean arg3);
endHead(myClass)

void func(myClass, myFunction, int arg1, String *arg2, boolean arg3);

The Class File

In the class file, the class's instance variables and methods must be instantiated with a similar syntax to the interface:

    classDef(className)
    
    ***METHOD AND IVAR INSTANTIATION HERE***
    
    endDef

Inside these keywords, the functions are instantiated with the macro

    mImp(className, functionName)

The instance variables are instantiated either with

    vImp(varName) = INITIAL_VALUE

    self->varName = initialValue.

Finally, outside the definition, the functions are defined with the same syntax as in the header:

  func(className, functionName, args) { IMPLEMENTATION }

Example myClass.m

classHead(myClass)
  vImp(myIvar) = 0; // or self->myIvar = 0
  mImp(myClass, myFunction);
endHead(myClass)

void func(myClass, myFunction, int arg1, String *arg2, boolean arg3) {
  printf("%d, %s, %d", arg1, arg2->cString, arg3);
}

When in a function definition, the keyword "self" can be used to reference the current instance of the class, similarly to Java's "this" or Objective-C's "self". Ex:

void func(myClass, myFunction, int arg1, String *arg2, boolean arg3) {
  printf("%d", self->myIvar);
}

Using a Class

Create a new instance

To create a new instance of a class, use the function

create(classType)

When calling an instance method of a particular class, use the syntax

i$(className, functionName, args)

Provided Classes

A few basic classes are provided as examples of sorts. These include:

a linked list: LinkedList
a dynamically resizing Array: ArrayList
a hashmap: Dictionary
a String: String