Lilang is a toy compiled language with syntax simillar to C written in Python. The compiler uses sly and llvmlite projects. Sly for lexing and parsing, llvmlite for code generation. The purpose of this project is to learn and experiment with compiler design.
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Dependencies
gcc>=9.3pip>=20.0.2git
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Clone git repo:
git clone https://github.com/presztak/lilang.gitcd lilang
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Build and install
python setup.py bdist_wheelpip install dist/lilang-*.whl
pip install -e .[dev]
python -m unittest discover -s tests
isort lilang
flake8
Source code of the Hello world program is below.
Filename: hello_world.li
prints("Hello world");
$ lilang hello_world.li
$ ./bin/hello_world
An integer is a number without a fractional component. It takes up 32 bits of space.
Syntax:
int x = 10;
printi(x);
A bool is a data type which can store true or false.
Syntax:
bool b = true;
String is a data type which contains collection of characters in double quotes.
Syntax:
string s = "Hello";
prints(s);
An Array is a collection of multiple values. Lilang supports arrays of integers and bools. In Lilang, the values going into an array are written as a comma-separated list inside square brackets.
Syntax:
int[] x = [1, 2, 3, 4];
printi(x[0]);
Multi-dimensional arrays can be defined using multiple squere brackets.
Syntax:
int[][] x = [[1, 2], [3, 4]];
printi(x[0][1]);
Use the if statement to specify a block of code to be executed if a condition is true.
If statement start with if keyword, which is followed by condition in parentheses. The block of code we want to execute if the condition is true is placed after the condition inside curly brackets. If the condition is not true then else block will be executed.
Syntax:
int x = 1;
if (x < 5) {
prints("true");
} else {
prints("false");
}
The while loop loops through a block of code as long as a specified condition is true.
While statement start with while keyword, which is followed by condition in parentheses. The block of code we want to execute if the condition is true is placed after the condition inside curly brackets.
Sytax:
int x = 0;
while (x < 10) {
printi(x);
x = x + 1;
}
for statement is a repetition control structure that allows you to write a loop that needs to execute a specific number of times.
It has three parts:
- init expresion
- contidion expresion
- increment expresion
The block of code to execute is placed in curly brackets.
Syntax:
for (int i = 0; i < 10; i += 1;) {
printi(i);
}
The break statement ends the loop immediately when it is encountered.
Syntax:
for (int i = 0; i < 10; i += 1;) {
if (i > 5) {
break;
}
printi(i);
}
The continue statement skips the current iteration of the loop and continues with the next iteration.
Syntax:
for (int i = 0; i < 10; i += 1;) {
if (i < 5) {
continue;
}
printi(i);
}
Function is a block of code designed to perform a particular task.
Function definition start with return type, which is followed by name of function. In parentheses we define arguments of the function. The block of code we want to execute is placed inside curly brackets.
Syntax:
void f() {
printi(10);
}
f();
Function with arguments:
int f(int a, int b) {
return a + b;
}
printi(f(5, 6));
Lilang supports functions with variable number of arguments.
Syntax:
int f(int ...b) {
return b[0] + b[2];
}
printi(f(1, 3, 4));
Type casting refers to changing an entity of one datatype into another.
Syntax:
bool a = bool(10);
int b = int(a);
There are two variables:
argcwhich is int and contains number of arguments. If no argument is supplied, argc will be 1 (name of program itself counts as 1)argvwhich is array of strings and contains arguments names. argv[0] holds the name of program.
Syntax:
for (int i = 0; i < argc; i += 1;) {
prints(argv[i]);
}
More examples can be found in 'tests' directory.