Scopes and contexts
All Ferret code exists within a private scope.
Execution of a Ferret program begins at the file level. There's
main routine-- we just jump right into the first line.
By default, variables are accessible only within the scope where
they're defined. So,
$who below would not be accessible in another
file since it belongs to the private top level file scope.
$who = "World" say("Hello, $who!")
$who to another file, we'll add both files to
package Greeting and
share the variable.
package Greeting share $who = "World"
package Greeting share $who say("Hello, $who!")