hello|
define split<1> as [
    set {} -> list|
    set '' -> word|
    set 0 -> i|
    do [
        do [
            set variable list + {variable word;} -> list|
            set '' -> word|
        ] else [
            set variable word + argument #1{variable i} -> word|
        ] if argument #1{variable i} = ' '|
        set variable i + 1 -> i|
    ] until variable i = do len<argument #1;>|
    do skip else set variable list + {variable word;} -> list if variable word = ''|
    return variable list|
]|

define calc<1> as [
    set {} -> middle|
    set 1 -> i|
    do [
        set variable middle + {argument #1{variable i};} -> middle|
        set variable i + 1 -> i|
    ] until variable i = do len<argument #1;> - 1|
    return variable middle|
]|

set do input<':';> -> x|
set do "split"<variable x;> -> list|
do print<do "calc"<variable list;>;>|
goodbye|