Tox Programming Language

Tox is a small programming language designed to run on a Virtual Machine. The Virtual Machine executable is located in vm/. This programming language was built using the library ply.

Note: The Virtual Machine was developed by students at the University of Minho, Portugal.I did not develop the Virtual Machine, I only developed the programming language. To learn more about the Virtual Machine, please refer to the zip file vms-vf.zip in the vm/ directory. Also note that I made some modifications to the Virtual Machine in order to make it compatible with the Virtual Machine at EWVM. Those modifications include:

• Adding a new instructions to the Virtual Machine (AND, OR).
• Improving the memory consumption of the Virtual Machine by reducing the number of memory leaks.

Installation

Installing through pip:

git clone https://github.com/fabiocfabini/tox.git
cd tox
make install

Note: Only works on linux.

Quick Start

tox run examples/hello_world.tox

Features

Comments

To add one line comments, simply type // followed by the comment. For example:

// This is a comment

Multiline comments can be added by typing /* followed by the comment and */ at the end. For example:

/*
This is a multiline comment
*/

Data Types

Has of now, the language supports the following data types:

• int, float, string: These are the basic data types of the language;
• &int, &float, &string: These are the pointer data types of the language;
• vec<int>, vec<float>, vec<string>: These are the vector data types of the language;

Arithmetics

Basic arithmetics are supported by the language. These include:

• the +, -, *, / operators;
• the ==, !=, <, >, <=, >= operators;
• the &&, || operators;
• the ! operator;

Tox also supports pointer arithmetics. The following operations are supported:

• + adds an integer to a pointer;
• - subtracts an integer from a pointer and returns the difference between two pointers;
• >, <, >=, <= compares two pointers;

Variables

To declare a variable, simply type the variable name followed by : and the variable type. For example:

a: int

Variables declared in this way are initialized with the value 0. To declare a variable and initialize it with a value, simply type the variable name followed by : and the variable type followed by = and the value. For example:

a: int = 10

To modify the value of a variable, simply type the variable name followed by = and the value. For example:

a = 20

To typecast a variable, simply prefix the variable name with the type you want to typecast it to. For example:

a: int = 10
b: float = (float) a

Arrays

In tox arrays are declared in 3 different ways:

• Declaring an array of a specific size. This will initialize the array with the value 0;

a: vec<int>[10]

• Declaring an array through a list of values;

a: vec<int> = [10, 20, 30, 40, 50]

• Declaring an array with the ... operator;

a: vec<int> = [1 ... 10]

This will initialize the array with the values 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

To access an array element, simply type the array name followed by [ and the index of the element followed by ]. For example:

a[0]

Control Flow

The control flow of the language is similar to the control flow of C. These include:

• if, if else and if else if statements;

if expression {
    // code
}

// or

if expression {
    // code
} else {
    // code
}

// or

if expression {
    // code
} else if expression {
    // code
} else {
    // code
}

• while statements;

while expression {
    // code
}

• do while statements;

do {
    // code
} while(expression)

• for statements;

for(i: int = 0; i < 10; i = i + 1) {
    // code
}

Functions

To declare a function start with the key word func followed by the function name, the function parameters and the function return type. For example:

func sum(a: int, b: int) -> int {
    return a + b
}

To call a function, simply type the function name followed by the function parameters. For example:

sum(10, 20)