A CIL Tutorial - Department of Computer Science - ETH Zürich

CHAPTER 14. IMPLEMENTING A SIMPLE DSL 124
../test/tut14.c
argument(int, boolarg) {
.short_form = "b",
.help_text = "A boolean argument",
};
The program also accepts an argument called intarg that species a particular integer. Setting the
has opt eld to ARG HAS OPT indicates that the argument takes an option, which is parsed using
the given format specier. It can be passed with --intarg n or -i n, and then the value n will be
accessable in the program through the variable intarg. We have also stated a requirement that the
given number must bigger than 0.
../test/tut14.c
argument(int, intarg, mandatory) {
.short_form = "i",
.help_text = "An integer argument (>0)",
.format = "%d",
.requires = arg_assert(intarg > 0),
.has_opt = ARG_HAS_OPT,
};
int main(int argc, char *argv[])
{
printf("%d %d\n", boolarg, intarg);
return 0;
}
This example can be compiled by saying:
$ ciltutcc --enable-tut14 -o tut14 test/tut14.c
Then we can run tut14 and supply the correct arguments:
$ ./tut14 -i 4 --boolarg
1 4
But now let's see what happens when we get it wrong:
$ ../tut14 --intarg -5
Improper arguemnts
-b,boolarg A boolean argument (0)
-i,intarg An integer argument (>0) (mandatory)