#!/usr/bin/ruby
# https://rosettacode.org/wiki/Palindrome_detection#Sidef
func palindrome(s) {
    if (s.len <= 1) {
        true
    }
    elsif (s.char_at(0) != s.char_at(-1)) {
        false
    }
    else {
        __FUNC__(s.substr(1, -1))
    }
}
var str = 'In girum imus nocte et consumimur igni';
palindrome(str.lc - /\s+/g) || die "error!";
palindrome('sidef')         && die "error!";
palindrome('salàlas')       || die "error!";
say "** Test passed!";