#programming-language #interpreter #arabic #islamic

bin+lib qalam

Interpreter for the Qalam programming language. Qalam is a dead-simple, Islamic/Arabic terminology inspired, interpreted programming langauge.

1 unstable release

0.1.0 Aug 21, 2024

#196 in Programming languages

MIT license

140KB
3.5K SLoC

qalam

Islamic/Arabic terminology inspired, dead-simple, interpreted, programming language

Table of Contents

Introduction

As a learning exercise, to really hone my skills, I wanted to write a programming language myself. In order to accomplish this, I'm following the amazing tutorial called Crafting Interpreters by Robert Nystrom.

While Robert goes through the entire process, step-by-step, to create a programming language he calls Lox, I didn't want to simply follow a tutorial and copy-paste code. I have found that real learning occurs when you change up tutorials a little so that you can have a deeper understanding.

In order to do this, I decided to create my own syntax for the language with the same general features as Lox. I also decided to use Rust to make the language instead of Java so that I cannot possibly copy-paste code.

Using qalam

  1. Install the qalam interpreter
cargo install qalam
  1. Create a .qlm file with your source code
echo "qul \"hello world!\"" > main.qlm
  1. Run the qalam code
qalam main.qlm
>> hello world!

Syntax

Keywords

Syntax Meaning/Inspiration Usage
niyya Intention. Signifies the intention to store a value. Variable declarations
amal Good Deeds/Actions. Functions do things (actions/deeds) Function declarations
radd To return (Arabic) Return statement
qul To say (Arabic) Print statement
ghaib Unseen, hidden. Signifies a value is not present Null value
niyya a = 1;
niyya b = 2;

amal add(a, b) {
  radd a + b;
}

qul add(a, b);
// prints 3

Conditionals

Syntax Meaning/Inspiration Usage
shart Condition. If a condition is satisifed, do something. If statement
illa Else. Self-explanatory Else statement
ilshart Combination of shart and illa Else-if statement
haqq Truth. A boolean true is the epitome of truth. Boolean true value
batil Falsehood. A boolean false is the epitome of falsehood. Boolean false value
wa and (Arabic). Self-explanatory. And operator. Can also use &&
aw or (Arabic). Self-explanatory. Or operator. Can also use ||
la not (Arabic). Self-explanatory. Not operator. Can also use !
niyya a = haqq;
niyya b = batil;

shart(a wa b) {
  // do something
} ilshart(la a) {
  // do something
} illa {
  // do something
}

Loops

Syntax Meaning/Inspiration Usage
tawaf Circumbulate. The name for circumbulating around the Ka'bah for Hajj. Signifies going around and around. For loop
baynama While (Arabic). Self-explanatory While loop
iftar Breaking fast. The time when Muslims break fast is called iftar. Break statement
safar Journey or travel. Signifies the loop is going to continue on it's journey. Continue statement
tawaf(niyya i = 0; i < 10; i = i + 1) {
  qul i; 
  // prints 0 to 9
}

niyya a = haqq;
niyya i = 0;
baynama(a) {
  shart (i < 10) {
    qul i;
    // prints 0 
    i = i + 1;
    safar;
  } illa {
    iftar;
  }
}

Objects (Classes)

Syntax Meaning/Inspiration Usage
kitab Chapter (literal: Book) (Arabic). In Islamic books, chapters are called kitab. Classes are similar to chapters as they group related data together. Class definition
khalaq To create (Arabic). The constructor creates the class object. Class constructor function
nafs Self/Soul. Islamically, nafs is used to describe desires of the self. Represents the state of the instance (self). Instance accessor (this in JavaScript, self in Python/Rust)
ulya Most elevated, superior (Arabic). The superclass is superior to the subclass. Superclass accessor (super in JavaScript)
ibn Son of/Child of (Arabic). Subclasses inherit from the superclass as children inherit from parents Class inheritance operator
kitab Animal {
  khalaq(name, sound) {
    nafs.name = name;
    nafs.sound = sound;
  }

  speak() {
    qul nafs.sound;
  }
}

kitab Feline ibn Animal {
  khalaq(name, sound) {
    ulya.khalaq(name, sound);
  }

  purr() {
    qul "purr"
  }
}

niyya cat = Feline("Hurayra", "Meow");
cat.speak();
// prints "meow"
cat.purr()
// prints "purr"

Types

Below are the built-in types supported by qalam:

Type Description Initialization Example
number Numerical value. All numbers are stored as floating point values. Numbers without a fractional part are considered as integers. niyya num = 1.0;
string Collection of characters. Characters can be indexed with integers. Initialize with double quotes. niyya name = "Ammar";
bool Boolean true or false. haqq = true, batil = false. niyya is_foo = haqq;
array Collection of any values. Values can be indexed and set with integers. Initialize with square braces. niyya arr = [1, "one", haqq];

Native Functions

I've implemented a few native functions to the program:

Function Name Parameters Return Type Description
clock number Returns the time elapsed since the epoch in seconds
typeof arg: any string Returns type of argument as a string
str arg: any string Converts the argument to a string
str2num arg: string number Converts the argument to a number. Throws error if not possible.
substr arg: string, start: number (positive int), length: number (positive int) string Returns a substring of the argument starting at start with length of length
index_of arg: string, substring: string number Returns the index of the start of a substring in the argument. Returns -1 if not found.
replace arg: string, old_substr: string, new_substr: string string Replaces all occurrences of old_substr in the argument with new_substr.
len arg: string | array number Returns the length of a string or array.
max a: number, b: number number Returns the maximum of the inputs
min a: number, b: number number Returns the minimum of the inputs
pow base: number, exp: number number Raises the base to the power of the exponent
random min: number, max: number number Returns a random number in the range of min to max
random_int min: number (int), max: number (int) number Returns a random integer in the range of min to max
push arr: array, val: any ghaib Pushes a value to the end of an array
pop arr: array any Pops a value from the end of the array and returns it. If it does not exist, returns ghaib
Array size: number (positive int), value: any array Creates an array of size values all initialized to value.
code char: string number Returns the character code for a single character string.
floor num: number number Returns the closest integer less than or equal to num
ceil num: number number Returns the closest integer greater than or equal to num
round num: number number Returns the closest to num. If num is halfway between 2 integers, returns away from 0.

Complete Example

To showcase the functionalty of qalam, I've provided an example below of reversing a linked list:

kitab ListNode {
  khalaq(value, next) {
    nafs.value = value;
    nafs.next = next;
  }
}

amal list_to_string(head) {
  niyya string = "";
  niyya curr = head;
  baynama(curr != ghaib) {
    string += str(curr.value);
    shart(curr.next) {
      string += " -> ";
    }
    curr = curr.next; 
  }

  radd string;
}

niyya list = ListNode(1, ListNode(2, ListNode(3, ListNode(4, ListNode(5, ghaib)))));

amal reverse_list(head) {
  niyya prev = ghaib;
  niyya curr = head;
  niyya next = ghaib;
  baynama(curr != ghaib) {
    next = curr.next;
    curr.next = prev;
    prev = curr;
    curr = next;
  }

  radd prev;
}

qul "Original list:";
qul list_to_string(list);
qul "Reversed list:";
qul list_to_string(reverse_list(list));

Output

Original list:
1 -> 2 -> 3 -> 4 -> 5
Reversed list:
5 -> 4 -> 3 -> 2 -> 1

More Examples

I've provided many more examples, in the examples directory. You can run them with cargo run --example <name> or by running the main.qlm file inside the examples subdirectory with qalam <file_path>.

Speed

qalam is an interpreted language with dynamic types. However, since there are essentially zero optimizations done, it is extremely slow. I am also an extreme amateur when it comes to Rust programming, therefore, it is probably even slower than Robert's implementation in Java as I definitely did a million things wrong when using Rust.

In order to showcase how slow it actually is, I'll compare it's speed to JavaScript and Python (interpreted, dynamically typed languages). For the comparison, I'll use the calculation of the 30th fibonacci number using a recursive algorithm.

Below are the scripts for each language

Python

import time

def fib(n):
  if n <= 1:
    return n
  else:
    return fib(n - 1) + fib(n - 2)

start = time.time()
result = fib(30)
end = time.time()
print(f"{end - start}")

JavaScript

function fib(n) {
  if (n <= 1) {
    return n;
  } else {
    return fib(n - 1) + fib(n - 2);
  }
}

let start = Date.now() / 1000;
let result = fib(30);
let end = Date.now() / 1000;
console.log(`${end - start}`);

Qalam

amal fib(n) {
  shart(n <= 1) {
    radd n;
  } illa {
    radd fib(n - 1) + fib(n - 2);
  }
}

niyya start = clock();
niyya result = fib(30);
niyya end = clock();
qul(str(end - start));

Each test was run 10 times and the average runtime is tabulated below:

Language Average Runtime (s)
JavaScript 0.0185
Python 0.2238
Qalam 78.2590

JavaScript and Python take less than second each. Qalam takes more than a minute. It is extremely slow, however, I am still proud that it works lol.

Dependencies

~690KB
~12K SLoC