"The progressive development of man is vitally dependent on invention." Nikola Tesla

After cloning this repository on your computer, run the prompt below to generate the interpreter build.

g++ -g -std=c++20 $(find src/ -type f -name "*.cpp") -o langlang.out
./langlang.out <langlang_file>

g++ -I../googletest/googletest/include -I../googletest/googletest \
    -L../googletest/build/lib -lgtest -lgtest_main -pthread \
    $(find tests/ -type f -name "*.cpp") $(find src/*/ -type f -name "*.cpp") -o run_tests.out && ./run_tests.out
./run_tests.out

LangLang is an object-oriented programming language with robust features such as higher-order functions, conditional structures, loops, class support, and inheritance. It is designed to be expressive and easy to use, with built-in input (<<) and output (>>) capabilities for direct terminal interaction.

Copy and run the file below to have your first contact with LangLang

>> "Hello, World!";

Run with the command:

./langlang.out hello.ll

In LangLang, variables are declared using var, followed by the variable name, its type, and an initial value:

var x -> number := 5;
var name -> string := "John";

• ->: Defines the variable type.
• :=: Assigns an initial value.

LangLang supports the following data types:

• number: Represents integers or floating-point numbers.
• string: Represents character strings.
• func: Represents functions.
• <identifier>: User-defined classes can also be used as types.

LangLang supports comments using the following syntax:

<> This is a comment

LangLang supports conditional structures using the if-else syntax:

if (condition) {
  // code block
} else {
  // alternative block
}

Example:

if (10%3 == 1) {
  >> "Yes";
} else {
  >> "No";
}

LangLang supports both while and for loops for repeating blocks of code.

The while loop repeats a block of code as long as a condition is true:

while (x > 0) { 
	>> x;
	x := x - 1;
}

The for loop in LangLang is used to iterate over a range of values. Its syntax is:

for (var i -> number := start_value; i < end_value; i := i + step_value) {
  // code block
}

• start_value: Initial value of the loop variable.
• end_value: Condition to terminate the loop.
• step_value: Value by which the loop variable is incremented each iteration.

LangLang allows the creation of functions using the func keyword:

func function_name() -> return_type {
  // function body
  // return <value>
}

Example:

func counter() -> func -> void {
  var i -> number := 0;
  func count() -> void {
    i := i + 1;
    >> i;
  }
  return count;
}

Functions can return other functions, allowing a functional programming style:

var cc -> func -> void := counter();
cc();

LangLang is an object-oriented language, supporting the creation of classes and instances:

Classes are defined using the class keyword:

class person {
  var age -> number := 12;
  var name -> string := "John";

  func print() -> void {
    >> "Hello, I am" >> name;
  }
}

To create an instance of a class:

var p -> person := person();
p.print();

LangLang supports inheritance between classes. A child class inherits the properties and methods of the parent class:

class student : person {
  var code -> number;
  
  func print() -> void {
    >> "Hi, I am a student, my name is" >> name;
  }
}

LangLang has built-in support for input with << and output with >>:

>> "Enter your name:";
<< name;