C3 language

Introduction

As an example language, the c3 language was created. As pointed out clearly in c2lang, the C language is widely used, but has some strange contraptions. These include the following:

  • The include system. This results in lots of code duplication and file creation. Why would you need filenames in source code?
  • The comma statement: x = a(), 2; assigns 2 to x, after calling function a.
  • C is difficult to parse with a simple parser. The parser has to know what a symbol is when it is parsed. This is also referred to as the lexer hack.

In part for these reasons (and of course, for fun), C3 was created.

The hello world example in c3 is:

module hello;
import io;

function void main()
{
    io.println("Hello world");
}

Language reference

Modules

Modules in C3 live in file, and can be defined in multiple files. Modules can import each other by using the import statement.

For example:

pkg1.c3:

module pkg1;
import pkg2;

pkg2.c3:

module pkg2;
import pkg1;

Functions

Function can be defined by using the function keyword, followed by a type and the function name.

module example;

function void compute()
{
}

function void main()
{
    main();
}

Variables

Variables require the var keyword, and can be either global are function local.

module example;

var int global_var;

function void compute()
{
    var int x = global_var + 13;
    global_var = 200 - x;
}

Types

Types can be specified when a variable is declared, and also typedeffed.

module example;
var int number;
var int* ptr_num;
type int* ptr_num_t;
var ptr_num_t number2;

If statement

The following code example demonstrates the if statement. The else part is optional.

module example;

function void compute(int a)
{
    var int b = 10;
    if (a > 100)
    {
        b += a;
    }

    if (b > 50)
    {
        b += 1000;
    }
    else
    {
        b = 2;
    }
}

While statement

The while statement can be used as follows:

module example;

function void compute(int a)
{
    var int b = 10;
    while (b > a)
    {
        b -= 1;
    }
}

For statement

The for statement works like in C. The first item is initialized before the loop. The second is the condition for the loop. The third part is executed when one run of the loop is done.

module example;

function void compute(int a)
{
    var int b = 0;
    for (b = 100; b > a; b -= 1)
    {
        // Do something here!
    }
}

Other

C3 does not contain a preprocessor. For these kind of things it might be better to use a templating engine such as ninja2.