example:
// set var
set n 0
set t 3
set one 1
set two 2
set nl \n
set file open file.txt w
// show text
show 1
show 2
show 3
show % one
// file tools
file write data // write
set file_read read file
// input
set inp input /:
// if
if n == 0 show n==0
if n != 1 show n!=1
// operators: +=, -=, *=, /=
n += 1 . int
n -= % one int
file_read += % nl str
n *= 2 . int
// load script.ns
load main1.ns
// run
run ls
run echo 1 2 3
// end
end