Introduction

Jactl is a language that looks very much like a simplified Java with a few additional features stolen from Groovy and Perl. If you are familiar with Java it will be an easy language to pick up.

Here is an example Jactl that defines a recursive function for calculating factorials and then invokes it:

long fact(long x) {
  if (x <= 1) {
    return 1
  }
  return x * fact(x - 1)
}

long n = 7
println "Factorial of $n is: ${fact(n)}"

Functions will, by default, return the value of the last expression encountered in the function so return is often not needed and since Jactl is optionally typed we can rewrite the code above more like this:

def fact(x) { x <= 1 ? 1 : x * fact(x - 1) }

def n = 7
println "Factorial of $n is: ${fact(n)}"