The Toy Programming language

An interpreted language implemented in C++

Table of Contents

• Installation
• Short Guide
• Real Application Example
• Builtin Functions
• Contacts

Installation

In order to work with the language, you need to build it on your local machine. You have to clone the project from this repo and build it using CMake

Attention! You need to exclude 'tests' from directories listed in root CMakeLists.txt because the testing library (Google Test) is gitignored

git clone https://github.com/it1shka/toylang
cd toylang
codium CMakeLists.txt # open CMakeLists.txt in any text editor

After doing if everything is done successfully, you will see CMakeLists.txt file (it will look similar to the one listed below):

project(toy_lang)
# Exclude "tests" folder from the array below -- it's important!
set(DIRECTORIES "utils" "lexer" "parser" "interpreter" "app" "tests") # Exclude the last

foreach(directory ${DIRECTORIES})
    message("Adding a subdirectory: ${directory}")
    add_subdirectory(${directory})
endforeach()

Finally, you are ready to build:

cmake .
cmake --build app

And you can find an executable following the path: "toylang/app/toy_lang_app":

cd app
./toy_lang_app help

Short Guide

1. Variable declaration

let a = 1;
let b = a + 2;
let c;

2. For loop

for (i from 1 to 10) {
    echo "Hello, " + i;
}

let sum = 0;
for (i from 1 to 100 step 2) {
    sum += i;
}

3. While loop

while (true) {
    println("Infinite cycle");
}

let a = 0;
while (a < 10) a += 1;

4. Flow operators (break, continue, return)

let running = true;
while (running) {
    if (input() == 'exit') break;
    else continue; # Just for illustration purposes,
                   # makes no sense
}

fun add(a, b) {
    return a + b;
}

fun doSomething() {
    echo "Doing something";
    return; # For illustration purposes
            # makes no sense
}

5. If-Else statement

let info = [input("Name: "), input("Surname: ")];
if (info == ["Tikhon", "Belousov"]) echo "you are author";
else {
    echo "you are user";
}

6. Functions

fun map(arr, fn) {
    let output = array();
    for (i from 0 to size(arr)) {
        let elem = arr[i];
        output += fn(elem);
    }
    return output;
}

fun main() {
    let numbers = [1, 2, 3, 4, 5];
    let doubled = map(numbers, lambda(x) { return x * 2; });
    echo doubled;
}

7. Import/Export

# library.toy
exports.add = lambda(a, b) {
    return a + b;
};

# lib2.toy
fun subtract(a, b) {
    return a - b;
}
exports = subtract;

# main.toy
import library as lib;
import lib2;
echo lib.add(1, 2);
echo lib2(2, 1);

8. Output to the console

echo "Hello world!"; # Prints to the output and hits new line
println("Hello, ", "world!"); # The same as echo, but accepts multiple args
print("Hello, world!"); # Prints without new line

9. Creating objects and values

let a = 1.123123123;
let b = "Hello";
let c = 'world';
let d = true and false;
let nothing = nil;
let names = ['Tikhon', 'Sasha', "Mateusz", "Jan"];
let add = lambda(a, b) { return a + b; };
let me = obj {
    "name": "Tikhon",
    "surname": "Belousov",
    "age": 19,
};

10. Math operators:

=, or, and, ==, !=, <, >, <=, >=, -, +, *, /, div, mod, ^, not

11. OOP

fun Cat(name) {
    
    let foodEaten = 0;

    fun meow() {
        echo "Cat " + name + "said meow!";
    }
    
    fun purr() {
        echo "Cat " + name + "said purrrrr!";
    }
    
    fun feed(food) {
        foodEaten += food;
    }
    
    fun hungry() {
        return foodEaten < 100;
    }
    
    return obj {
        "meow": meow,
        "purr": purr,
        "feed": feed,
        "hungry": hungry,
    };
}

Real Application Example

I built a minesweeper console app in my language. You can find it here

Builtin Functions

Below there is a list of functions included in language prelude

1. size(array) Returns the size (number of elements) of the given array.

2. chars(string) Converts a string into an array of individual characters.

3. abs(number) Returns the absolute value of the given number.

4. all(array) Returns true if all elements in the array evaluate to true; false otherwise.

5. any(array) Returns true if any element in the array evaluates to true; false otherwise.

6. print(...args) Prints the string representations of the provided arguments to the standard output.

7. println(...args) Prints the string representations of the provided arguments to the standard output, followed by a newline.

8. array(...args) Creates an array containing the provided arguments.

9. input(...args) Prints the string representations of the provided arguments, then reads a line of input from the user.

10. bool(value) Converts the given value to a boolean.

11. number(value) Converts the given value to a number.

12. max(array) Returns the maximum value in the array.

13. min(array) Returns the minimum value in the array.

14. range(start, end, step) Generates an array of numbers from start to end with the specified step size.

15. typeof(value) Returns the type of the given value as a string.

16. str(value) Converts the given value to its string representation.

17. sum(array) Computes the sum of all elements in the array.

18. slice(array, start, end) Returns a sub-array from the specified start index to the end index.

19. reversed(array) Returns a new array with the elements in reverse order.

20. read(filename) Reads the contents of a file specified by the filename.

21. write(filename, content) Writes the content to a file specified by the filename.

22. round(number) Rounds the given number to the nearest integer.

23. trunc(number) Truncates the given number towards zero.

24. keys(object) Returns an array of keys from the given object.

25. values(object) Returns an array of values from the given object.

26. wait(milliseconds) Pauses the execution for the specified number of milliseconds.

27. cls() Clears the console screen.

28. rand(lower, upper) Generates a random number between the lower and upper bounds.

29. randint(lower, upper) Generates a random integer between the lower and upper bounds.

Contacts

In case you have some suggestions / bugs to share with me, feel free to contact me via email 2tishbel@gmail.com