Ostrich

Ostrich is an experimental interpreted programming language. The interpreter has been written in Golang. Ostrich is dynamically typed.

Getting Started

Install dependencies

Install Go on Ubuntu

sudo apt update
sudo apt upgrade
sudo apt install golang

Install Go on Arch Linux

sudo pacman -Syu
sudo pacman -Sy go

Run

git clone https://github.com/avadov/ostrich-interpreter.git
cd ostrich-interpreter
go run main.go

Basic Syntax

String literals

"This is a string"

Booleans

true
false

Variable declarations

let num = 123;
let name = "Some text";
let ok = true;
let result = 10 * (20 / 2);

Assignment statements

The assignment statement assigns a new value to a variable

name = "Another string"

Arithmetic operators

Unary:

- negation

Binary:

+ sum
- subtraction
* multiplication
/ division

Comparison operators

== equal
!= not equal
< less
> greater

String operators

+ concatenation

Arrays

An array is an ordered list of elements of possibly different types.

let myArray = [true, "Some text", 28, func(x) { x * x }];

Each element in the array can be accessed individually.

myArray[0];
myArray[3](2);

There are some built-in functions that work with arrays:

len(myArray) - the number of elements in myArray;
first(myArray) - returns the first element of myArray;
rest(myArray) - returns a new array containing all elements of myArray, except the first one (the cdr function). It returns a newly allocated array!;
last(myArray) - returns the last element of myArray;
push(myArray, "four") - allocates a new array with the same elements as the old one plus the new, pushed element. Doesn’t modify the given array.

Dictionaries

A dictionary maps keys to values.

let myHash = {"age": 33, true: "a boolean", 99: "an integer"};

The index operator gets values out of the dictionary:

myHash[true]
myHash["age"]
myHash[99]

Conditionals

if (x > 10) {
    puts("everything okay!");
} else {
    puts("x is too low!");
}

Functions

let add = func(a, b) { return a + b; };
add(5, 9);

Functions are ordinary variables. They can be passed as arguments to other functions.

let twice = func(f, x) {
    return f(f(x));
};

let addTwo = func(x) {
    return x + 2;
};

twice(addTwo, 2);

Output

Print the given arguments on new lines:

puts("hello", "world", 55, false)

License

Ostrich is available under the permissive MIT license.