anarchy golf - the source code

replace last occurrence FIXED by pooq

do
input""a$,b$,c$
if""=a$end
i=rinstr(c$,a$)
if i?mid$(c$,1,i-1),b$,mid$(c$,i+len(a$))
if!i?c$
loop

Note that non-ascii characters in the above source code will be escaped (such as \x9f).