peekiter

[dfdx]

Iterator wrapper that provides additional operation - peek(iter, state) - that allows to inspect head element without actually changing the iterator state. See #63 for discussion.

[mschauer]

Ah, 0.3 has no Nullable type, so this is a 0.4+ only iterator. But I think this can be fixed using @compat.

[dfdx]

using Compat should have already provided Nullable type, so this issue is a little bit trickier. I'll investigate it later today.

[dfdx]

Fixed. Turns out we returned Nullable(Nullable(val)) in peek(..). Julia 0.4 and 0.5 automatically unwrapped it into simpler Nullable(val), so using (not fully compatible) replacement from Compat on 0.3 actually uncovered a bug.

[kmsquire]

Seems useful. Can you add some documentation to the README?

Unless there is any objection, I'll merge this after it's documented.

[mschauer]

Not urgent, but what do you think about #63 (comment) making peekiter a noop for ranges?

[dfdx]

@kmsquire Done. Thanks for reminder. It's good to know that changes are being properly checked before merging!

@mschauer Ah, this is definitely a good addition. Should we also do the same thing for Array?

[dfdx]

If there are no more suggestions, could someone merge it, please?