On Tue, Jan 20, 2026 at 01:30:35PM +0100, Gabriele Monaco wrote: > On Tue, 2026-01-20 at 08:37 -0300, Wander Lairson Costa wrote: > > On Tue, Jan 20, 2026 at 09:59:11AM +0100, Gabriele Monaco wrote: > > > On Mon, 2026-01-19 at 17:45 -0300, Wander Lairson Costa wrote: > > > > Initialize loop variable `i` before the for loop in abbreviate_atoms > > > > function to fix pyright static type checker error. The previous code > > > > left `i` potentially unbound in edge cases where the range could be > > > > empty, though this would not occur in practice since the loop always > > > > executes at least once with the given range parameters. > > > > > > > > The initialization to zero ensures that `i` has a defined value before > > > > entering the loop scope, satisfying static analysis requirements > > > > while preserving the existing logic. The for loop immediately assigns > > > > i to the first value from the range, so the initialization value is > > > > never actually used in normal execution paths. > > > > > > > > This change resolves the pyright reportPossiblyUnbound error without > > > > altering the function's behavior or performance characteristics. > > > > > > So are we just pleasing the tool or is there a real implication of this? > > > > > > Apparently code like > > > > > > for i in range(len([]), -1, -1): > > > pass > > > print(i) > > > > > > works just fine since range() returns at least 0 (as you mentioned in the > > > commit > > > message) and i is not used before assignation in the loop, so I don't > > > really > > > see > > > a problem. > > > > > > Apparently pyright devs don't want ([1]) to implement a logic to sort out > > > the > > > /possibly/ unbound error here. > > > > > > From what I understand, this code is already not pythonic, so rather than > > > silence the warning to please this tool I'd just refactor the code not to > > > use i > > > after the loop (or leave it as it is, since it works fine). > > > > > > What do you think? > > > > You're right, I could have done: > > > > for atom in reversed(atoms): ... > > > > I'm missing what you mean with this, the range is iterating over the string > representation of atom (in reverse) not the array of atoms. >
Sorry, I misinterpreted you previous comment and picked the wrong piece of code. Yes, the basic goal was to make pyright happy. > You basically want i to be the length of the longest prefix common to at least > another atom. > > You could assign i to some python trick doing the exact same thing the loop > does, like: > > i = next((i for i in range(len(atom), -1, -1) > if sum(a.startswith(atom[:i]) for a in atoms) > 1)) > > next() is basically doing the break at the first occurrence from the > generator, > just now your i doesn't live (only) inside the loop. > > So now you save 2 lines and get any C developer scratch their head when they > look at the code, but hey, pyright is happy! > Or just leave the assignment. > If you do find the trick with next() readable or have any better idea, feel > free > to try though. > Definitely the next() trick is not worth to make pyright happy. > Thanks, > Gabriele > > > I will modify it in v2. > > > > > > > > Thanks, > > > Gabriele > > > > > > [1] - https://github.com/microsoft/pyright/issues/844 > > > > > > > > > > > Signed-off-by: Wander Lairson Costa <[email protected]> > > > > --- > > > > tools/verification/rvgen/rvgen/ltl2k.py | 1 + > > > > 1 file changed, 1 insertion(+) > > > > > > > > diff --git a/tools/verification/rvgen/rvgen/ltl2k.py > > > > b/tools/verification/rvgen/rvgen/ltl2k.py > > > > index fa9ea6d597095..94dc64af1716d 100644 > > > > --- a/tools/verification/rvgen/rvgen/ltl2k.py > > > > +++ b/tools/verification/rvgen/rvgen/ltl2k.py > > > > @@ -45,6 +45,7 @@ def abbreviate_atoms(atoms: list[str]) -> list[str]: > > > > > > > > abbrs = [] > > > > for atom in atoms: > > > > + i = 0 > > > > for i in range(len(atom), -1, -1): > > > > if sum(a.startswith(atom[:i]) for a in atoms) > 1: > > > > break > > > >
