func:each

each(val, fn)

Iterate the items of a collection:

• Grid: iterate the rows as (row, index)
• List: iterate the items as (value, index)
• Dict: iterate the name/value pairs (value, name)
• Str: iterate the characters as numbers (char, index)
• Range: iterate the integer range (integer)
• Stream: iterate items as (val); see Streams