Julia

Overview

Julia is a dynamically typed programming language that provides high performance. It is often used as an alternative to Python or Matlab for data visualization.

Julia has many things in common with Lua including:

dynamic types
no semicolons
no parentheses are conditions in if statements and loops
use of the endkeyword
1-based indexes
parallel assignment

Julia differs from Lua in that it is:

much faster than Lua and Python
much larger (not ideal for embedding in another app; 26MB vs 750KB)
supports the ternary operator

Julia source files have an extension of .jl.

Julia is great for applications that involve math. It supports a very concise syntax for defining functions like polynomials.

Julia uses the LLVM compiler infrastructure.

Installing

To install in macOS using Homebrew, enter brew install julia.

Running

To start a REPL, enter julia.

To execute a Julia source file, enter julia {file-name}.jl.

Examples

# Can precede a variable with a constant for implicit multiplication.
f(x) = 3x^2 + 7x - 2

for x = 0:5
  println("f($x) = $(f(x))")
end

g(x, y) = 3x^2 + 5x*y - 6y^2 + 4x - y + 8

# Can use Unicode characters and π is a predefined constant.
circleArea(r) = π*r^2

Jupyter Notebooks

Jupyter Notebooks can be configured to run Julia code as described here.

A popular alternative is JuliaHub which is the successor to JuliaBox.

Outstanding Queestions

Can Julia functions be called from Swift?
Can a Julia function return more than one value?
What happens if you call a function with too few or too many arguments?
Are anonymous functions restricted to only having one statement?
Is “broadcast” like the JavaScript Array map method?
How can Julia use packages implemented in other languages?