The Sidef Programming Language
** ** **** * ********* *********
* * ** * * **** ** ** ** ** ** ** **
** ** **** *** ********* * * *
** ** ** **** * * ****** ******
* * * * * * * * * **** ** ** ** ** ** **
** ** ** **** ****** ****** * *
** ** **** * * * ********* ***
* * ** * * **** ** ** ** ** ** ** **
** ** **** ********* ********* *
A modern, high-level programming language for versatile general-purpose applications
Website • Tutorial • Documentation • Try Online • Discussions
🌟 Why Sidef?
Sidef is a modern, expressive programming language that combines the elegance of Ruby, the versatility of Raku, and the mathematical power of a built-in computer algebra system. It features exact rational arithmetic by default, an extensive number theory library (1,000+ functions), and seamless Perl module integration — making it equally at home for scripting, mathematical research, and general-purpose programming.
# Exact rational arithmetic — no floating-point surprises
say (1/3 + 1/6) #=> 1/2
# Built-in number theory
say (2**127 - 1) #=> 170141183460469231731687303715884105727 (Mersenne prime)
say factor(2**64 - 1) #=> [3, 5, 17, 257, 641, 65537, 6700417]
# Expressive, concise syntax
say 71.primes #=> [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71]
✨ Key Features
Programming Paradigms
- Object-oriented programming with multiple dispatch
- Functional programming and pattern matching
- Lexical scoping and closures
- Keyword arguments and optional lazy evaluation
Numeric Computing
- Exact rational numbers by default
- Arbitrary-precision integers, floats, and complex numbers
- 1,000+ built-in number theory functions (backed by GMP, MPFR, MPC)
- Gaussian integers, quaternions, matrices, polynomials
Language & Integration
- Regular expressions and string interpolation
- Optional dynamic type checking
- Seamless Perl module integration
- REPL with interactive help (
-Hflag)
🚀 Quick Start
Prerequisites
Sidef requires Perl 5.18+ and the following C libraries:
| Library | Purpose | |---------|---------| | GMP | Big integers and rationals | | MPFR | Arbitrary-precision floats | | MPC | Arbitrary-precision complex numbers |
Debian/Ubuntu:
sudo apt-get install libgmp-dev libmpfr-dev libmpc-dev
Arch Linux:
sudo pacman -S gmp mpfr libmpc
Termux:
pkg install perl make clang libgmp libmpfr libmpc
Installation
Via CPAN:
cpan Sidef
# or (skip tests for faster install):
cpan -T Sidef
# or with cpanminus:
cpanm Sidef
Build from source:
git clone https://github.com/trizen/sidef.git
cd sidef
perl Makefile.PL
make
make test
make install
Via AUR:
trizen -S sidef
Platform packages:
- Arch Linux: AUR package
- Slackware: SlackBuilds
- Other systems: See pkgs.org
Hello World
say "Hello, World!"
sidef hello.sf
sidef -E 'say "Hello, World!"'
sidef -i # start the REPL
Try It Online
Experiment with Sidef instantly at Try It Online without any installation.
🔤 Language at a Glance
Variables and Types
var name = "Sidef" # String
var num = 42 # Number (exact integer)
var ratio = 3/7 # Rational (exact)
var arr = [1, 2, 3] # Array
var hash = Hash(a => 1, b => 2) # Hash
var block = {|n| n.is_prime } # Block
Functions and Pattern Matching
func greet(name) { "Hello, #{name}!" }
say greet("world") #=> Hello, world!
# Multi-dispatch / pattern matching
func fib({|n| n == 0 }) { 0 }
func fib({|n| n == 1 }) { 1 }
func fib(n) { fib(n-1) + fib(n-2) }
say fib(10) #=> 55
Object-Oriented Programming
class Animal(name, sound) {
method speak { say "#{name} says #{sound}!" }
}
class Dog(name) < Animal(name, "woof") {
method fetch { say "#{name} fetches the ball!" }
}
var d = Dog("Rex")
d.speak #=> Rex says woof!
d.fetch #=> Rex fetches the ball!
Functional Programming
var nums = 1..10 # Range object
# Map, filter, reduce
var evens = nums.grep { .is_even } #=> [2, 4, 6, 8, 10]
var squares = nums.map { |n| n**2 } #=> [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
var total = nums.reduce { |a, b| a + b } #=> 55
say evens
say squares
say total
Number Theory
say primes(50, 100) # array of primes in range [50, 100]
say prrime_count(10**9) # number of primes up to 10^9
say prime(100) # 100th prime => 541
say 12.divisors # [1, 2, 3, 4, 6, 12]
say euler_phi(100) # Euler's totient => 40
say gcd(48, 18) # => 6
say is_prime(2**521 - 1) # Mersenne prime check => true
Lazy Evaluation
# Infinite lazy list of primes
var lazy_primes = (2..Inf -> lazy.grep { .is_prime })
say lazy_primes.first(10) #=> [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
⌨️ Command-Line Reference
sidef [options] [script.sf] [script-arguments]
| Flag | Description |
|------|-------------|
| -E 'code' | Execute a one-line program |
| -e 'code' | Alias for -E |
| -i [file] | Start the interactive REPL (optionally loading a file) |
| -c | Compile script to a stand-alone Perl program |
| -C | Check syntax only (parse without execution) |
| -r | Deparse program back to Sidef code |
| -R lang | Deparse to another language (perl, sidef) |
| -P int | Set floating-point precision in bits (default: 192) |
| -O level | Optimization level: 0 (none), 1 (recommended), 2 (max) |
| -s | Enable precompilation (cache compiled code) |
| -t | Test mode: treat all arguments as script files |
| -D | Dump the Abstract Syntax Tree (AST) |
| -H | Interactive help mode for exploring documentation |
Examples:
sidef -E 'say 10.of { |i| i**2 }' # one-liner
sidef -i # start REPL
sidef -i script.sf # run script in REPL
sidef -C script.sf # syntax check
sidef -c -o output.pl script.sf # compile to Perl
sidef -P 400 -E 'say sqrt(2)' # 400-bit precision
sidef -O1 script.sf # with optimization
sidef -r script.sf # deparse to Sidef
sidef -t tests/*.sf # run test files
🖥️ Interactive Mode (REPL)
Start the REPL with sidef -i:
$ sidef -i
sidef> say "Hello!"
Hello!
sidef> x = 2**64
18446744073709551616
sidef> x.is_prime
false
sidef> is_prime(2**127 - 1)
true
sidef> 1..10 -> map { .square }.sum
385
sidef> quit
Use -H to open interactive documentation help:
sidef -H
🎯 Code Examples
Classes and Inheritance
class Shape {
method area { die "Not implemented" }
method describe { say "I am a #{self.class} with area #{self.area}" }
}
class Circle(r) < Shape {
method area { Num.pi * r**2 }
}
class Rectangle(w, h) < Shape {
method area { w * h }
}
Circle(5).describe #=> I am a Circle with area 78.539...
Rectangle(4, 6).describe #=> I am a Rectangle with area 24
Functional Array Processing
# FizzBuzz in one line
say (1..20 -> map { |n|
n%%15 ? "FizzBuzz" : (n%%3 ? "Fizz" : (n%%5 ? "Buzz" : n))
})
# Pipeline style
(1..50).grep { .is_prime } \
.map { .square } \
.first(5) \
.say #=> [4, 9, 25, 49, 121]
Number Theory One-Liners
say 100.by { .is_prime } # first 100 primes
say sum(1..100) #=> 5050
say prod(1..10) #=> 3628800 (10!)
say { .euler_phi }.map(1..10) #=> [1, 1, 2, 2, 4, 2, 6, 4, 6, 4]
The Y Combinator
Demonstrating functional programming with the Y combinator:
var y = ->(f) {->(g) {g(g)}(->(g) { f(->(*args) {g(g)(args...)})})}
var fac = ->(f) { ->(n) { n < 2 ? 1 : (n * f(n-1)) } }
say 10.of { |i| y(fac)(i) } #=> [1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880]
var fib = ->(f) { ->(n) { n < 2 ? n : (f(n-2) + f(n-1)) } }
say 10.of { |i| y(fib)(i) } #=> [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
Sierpinski Triangle
ASCII generation of the Sierpinski triangle:
func sierpinski_triangle(n) {
var triangle = ['*']
{ |i|
var sp = (' ' * 2**i)
triangle = (triangle.map {|x| sp + x + sp} +
triangle.map {|x| x + ' ' + x})
} * n
triangle.join("\n")
}
say sierpinski_triangle(4)
*
* *
* *
* * * *
* *
* * * *
* * * *
* * * * * * * *
* *
* * * *
* * * *
* * * * * * * *
* * * *
* * * * * * * *
* * * * * * * *
* * * * * * * * * * * * * * * *
Mandelbrot Set
ASCII visualization of the Mandelbrot set:
func mandelbrot(z, r=20) {
var c = z
r.times {
z = (z*z + c)
return true if (z.abs > 2)
}
return false
}
for y in (1 `downto` -1 `by` 0.05) {
for x in (-2 `upto` 0.5 `by` 0.0315) {
print(mandelbrot(Complex(x, y)) ? ' ' : '#')
}
print "\n"
}
#
# ### #
########
#########
######
## ## ############ #
### ################### #
#############################
############################
################################
################################
#################################### #
# # ###################################
########### ###################################
########### #####################################
############## ####################################
####################################################
######################################################
#########################################################################
######################################################
####################################################
############## ####################################
########### #####################################
########### ###################################
# # ###################################
#################################### #
################################
################################
############################
#############################
### ################### #
## ## ############ #
######
#########
########
# ### #
#
More Examples
Explore an extensive collection of Sidef programs at github.com/trizen/sidef-scripts
📚 Documentation & Learning Resources
| Resource | Description | |----------|-------------| | Beginner's Guide | Start here if you're new to Sidef | | Advanced Tutorial | Comprehensive language tutorial | | Number Theory Tutorial | Mathematical programming with Sidef | | Number Theory Reference | Complete function reference for number theory | | Number Theory Guide | Complete guide for computational number theory | | Computational Algebra Guide | Complete guide for computational algebra | | Sidef GitBook | Full language guide | | RosettaCode Examples | Practical code examples across many tasks |
💬 Community & Support
Have questions or need help? Join the conversation:
- Discussion Forum - Q&A and community discussions
- GitHub Issues - Bug reports and feature requests
📦 Distribution Availability
| Platform | Package | Link |
|----------|---------|------|
| CPAN | Sidef | metacpan.org |
| Package Search | Multiple distributions | pkgs.org |
| Arch Linux | sidef (AUR) | AUR Package |
| Slackware | perl-Sidef | SlackBuilds.org |
🤝 Contributing
Contributions of all kinds are welcome — bug reports, feature suggestions, documentation improvements, and pull requests. Please read CONTRIBUTING.md for guidelines on:
- Reporting bugs and suggesting features
- Setting up a development environment
- Code style and commit message conventions
- The pull request review process
📄 License and Copyright
Copyright © 2013-2026 Daniel Șuteu, Ioana Fălcușan
This program is free software; you can redistribute it and/or modify it under the terms of the Artistic License (2.0).
Full license: perlfoundation.org/artistic-license-20.html
Made with ❤️ by the Sidef community