incomplete inference with && and || branches #35090
Description
I have attached an MWE gist with an error for type inference discussed here on Discourse. It is relevant because I ran into this while working on this PR in Missings.jl
The MWE (though "minimum" is a stretch) defines a struct and then 3 mapreduce_impl functions. Two good, one bad.
The struct, TwoVectors, is two vectors x and y which both contain missing values. The goal is to mapreduce_impl across the x field while omitting elements where either x or y are missing.
All three mapreduce_impl functions have the same behavior, but the "bad" one doesn't infer correctly. They are all the exact same except for a section starting on the 4th line of each expression.
The "bad" one has this:
if a1 !== missing && !_anymissingindex(itr.others, ifirst)
return Some(Base.mapreduce_first(f, op, a1))
end
return nothing
The "good" one has this
if a1 === missing
return nothing
elseif _anymissingindex(itr.others, ifirst)
return nothing
end
return Some(Base.mapreduce_first(f, op, a1))
The "good2" one has this
a1 === missing || _anymissingindex(itr.others, ifirst) || return Some(Base.mapreduce_first(f, op, a1))
return nothing
The full @code_warntype output can be seen by calling MWEMissings.main().