[Gretl-devel] Re: Incrementing using the '++' operator

On Sun, 16 Jun 2019, Artur Tarassow wrote: > I really like the C-style if-else syntax as well as the C-style '++' and > '--' operators for incrementing and decrementing a number, respectively. But > I am surprised to see that the following does not work: > > <hansl> > scalar s = 0 > loop i=1..2 -q >     catch s = (i==1) ? 1 : +1    # no effect >     s >     catch s = (i==1) ? 1 : s++    # no effect >     s >     catch s = (i==1) ? 1 : s+1    # works as intended >     s > endloop > </hansl> > > Why is the 2nd approach not working here? According to the C standard an operation such as s = s++ leads to undefined behavior. In general, "s++" means, yield the current value of s then increment s, but with s itself on the left it's not clear what has to be done. So, not a gretl bug.