;; really simple calculator (add/subtract)
;;
loop while run = true:
src_in == get cli_opt(a);
if cli_opt = '0' then FAIL
else
continue
open_file(src_in) as #1
read (#1):
case of #1,1 :
if ';;' then continue
if "a" then var1 == "a"
case of #1,2 :
if ';;' then continue
if "+" then x = '+'
if "-" then x = '-'
case of #1,3 :
if ';;' then continue
if "b" then var2 == "b"
case of x:
if x = '+' then solution == var1 + var2
if x = '-' then solution == var1 - var2
else
FAIL
display solution