Descriptionvar is set to a, then body is repeatedly expanded, and var incremented, until
a = b. (var will be decremented if a > b). step can be used to cause the
increment to be other than +/- 1; its sign will automatically be adjusted to
make sure the loop terminates.
If the macro max-iteration is defined, it sets an upper limit to the number of
%for(i, 12, 3, %i%-, 2) => 12-10-8-6-4-