Icon is a high-level, general-purpose programming language with goal-directed evaluation and built-in support for strings and lists. It was developed at the University of Arizona.

How to test

Prerequisites: Icon compiler (icont)

  • Ubuntu/Debian: sudo apt install icont
  • macOS: Available via MacPorts — sudo port install icon
icont -s fibonacci.icn && ./fibonacci

Expected output:

0
1
1
2
3
5
8
13
21
34

Source Code

procedure main()
    a := 0
    b := 1
    every 1 to 10 do {
        write(a)
        c := a + b
        a := b
        b := c
    }
end

Local Testing Screenshot Image