A PROJECT IN DEVELOPMENT

Language

Contents

• Overview
• Frontend
• Backend & CPU
• Syntax
• Tree Example
• Programs
• How to Build

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Overview 🏐

Volleyball Programming Language is a project composed of three main components: Frontend, Backend, and CPU Emulator.

Note

Language features. At the moment, all operations and functions have not been implemented since the session started) , so here are the important notes:

• The program must have the main function of "volleyball";
• Functions do not accept arguments, and the return type is void;
• It is also worth considering that this implementation of the language is written on global variables (there are no local ones.

Each module has its own responsibility and cooperates to process, compile, and execute code written in a custom programming language inspired by volleyball terminology.

Frontend

• This component reads a text file containing a program written in the volleyball language.
• It performs lexical analysis to tokenize numbers, variables, functions, and operators.
• Then, it applies recursive descent parsing to check the syntax and build nodes for a tree structure that stores: element type, value, and pointers to children.
• The frontend also includes graphviz integration to visualize the syntax tree.
• The final output of the frontend is an Abstract Syntax Tree (AST) stored in data/tree_file.txt.

Backend & CPU

• The backend starts by reading and reconstructing the AST.
• It then generates assembly code for a custom stack-based virtual machine.
• The CPU part contains:
  • Assembler — converts the assembly code into bytecode.
  • Processor — reads the bytecode, decodes, and executes the commands.

Syntax 📘

Operation	Keyword	Translation
if	block	блокировка
while	rally	розыгрыш
return	ace	ace
printf	serve	подача
scanf	receive	приём

Comparison Operator	Keyword	Translation
==	scores_equal	счёт сравнялся
!=	scores_diff	счёт разный
>	leading	впереди
<	losing	отстаём
>=	not_behind	не позади
<=	not_losing	не проигрываем

Tree Example 🌳

Programs 🎮

To add a new program written in this language, first check the syntax rules, write your code in the data directory to a text file and run it.

Example Program: EquationSolver

SolveSquare

play volleyball()
{
    receive(a);
    receive(b);
    receive(c);

    block(a scores_equal 0)
    {
        block(b scores_equal 0)
        {
            serve(999);
            ace 0;
        }

        SolveLinSq();
        ace 0;
    }

    discr = b * b - 4 * a * c;
    c = sqrt(discr);

    block(discr scores_equal 0)
    {
        y = (-1 * b) / (2 * a);
        serve(y);
        ace 0;
    }

    block(discr leading 0)
    {
        SolveQuadSq();
        ace 0;
    }

    block(discr losing 0)
    {
        serve(999);
    }

    ace 0;
}

play SolveLinSq()
{
    q = (-1 * c) / b;
    serve(q);
    ace 0;
}

play SolveQuadSq()
{
    x  = (-1 * b - c) / (2 * a);
    xx = (-1 * b + c) / (2 * a);

    serve(x);
    serve(xx);

    ace 0;
}

Example Program: Factorial

Factorial

play volleyball()
{
    receive(x);

    block (x scores_equal 0)
    {
        serve(1);
    }

    block (x scores_diff 0)
    {
        r = 1;
        c = 1;

        rally (c not_losing x)
        {
            c = c + 1;
            r = r * c;
        }

        serve(r);
    }

    ace 0;
}

How to Build ⚙️

cd CPU
make all
cd ../build
cmake ..
make

../run.sh frontend "SolveSquare.txt"
../run.sh backend
../run.sh asm
../run.sh proc