Comments

//
// Foobar
#!/usr/bin/env io
/* multiline
comment
*/

Strings

"this is a \"test\".\nThis is only a test."
"""this is a "test".
This is only a test."""

Numbers

123
123.456
0.456
123e-4
123e4
123.456e-7
123.456e2

Full example

"Hello, world!" println
A := Object clone    // creates a new, empty object named "A"
factorial := method(n,
    if(n == 0, return 1)
    res := 1
    Range 1 to(n) foreach(i, res = res * i)
)