2026-08-12 –, Room 1
Type-piracy is often said to be "defining foreign behavior over foreign types".
Sounds intuitive, but in practice things get complicated quickly: A basic type like ForeignType{Float64} may be "obviously foreign", but how do we extend that notion to Julia's full type language including Union and where? Are all forms of type-piracy equally bad, or is "type-privateering" a thing? Most importantly, how does this affect your code in practice?
This talk will attempt to construct a mathematically precise definition for the "essence" of type-piracy. We'll discuss how determining type-piracy might be automated and what it would mean to make this a "first-class" restriction in Julia. Do we lose expressivity, gain performance? What designs would this affect in practice?
Along the way, we'll examine cases of "type-piracy in the wild" in the community (and even in Julia's own standard libraries!). These controversial case studies will serve as a litmus test to see if we can conquer the type seas, or if the age of the type-privateer continues.
A compiler engineer at JuliaHub.