Hello all! :wave: I’ve been collecting a few of the most cursed corner cases of Julia WATs that I know of here (WIP), but I would appreciate if people could share their own rare specimens as well. Please ping me with your contributions and I’ll post with proper credit. Here’s an example of what I…

I still don’t get it, since Union{} is not a valid tuple field type: Tuple{Union{},Union{}} ERROR: Tuple field type cannot be Union{} so it should be ignored for the purposes of the expression above. I think this is a bug and you should open an issue. (But let’s wait for others, I am not an exper…

[image] Tamas_Papp: Would someone kindly explain why this is? EDIT: this is now fixed (in a PR, soon to be merged, I guess). See Intransitivities in subtyping It’s AFAIK not possible, even in theory, to implement the subtyping (<:) so that it always returns true when a human would expect tha…

A relevant PR, to expand the <: doc string: doc: expand the `<:` doc string JuliaLang:master ← nsajko:doc_subtype opened 12:26PM - 22 Jan 24 UTC (UTC) [nsa…

This thread/post would be a great source of cases for a “clippy” style linter. Rusts linting is top class and we should definitely learn from it, to help avoid errors that people might stumble upon, but that can’t be fixed by changing syntax/parsing.

[image] Larbino1: This thread/post would be a great source of cases for a “clippy” style linter. In principle I agree with you, but TBH I’m not sure if VS Code ever pointed out an actual issue to me (except syntax errors), while it sadly points out many false positives. IMO the linting for Ju…

I completely agree, the current VSCode linter needs work. I’m just a user, I’ve never worked on linting, and I appreciate there must be huge number of challenges, especially in a much more dynamic/flexible language like Julia. However, I think linting is a very useful tool and its a shame that we d…

[image] Tamas_Papp: I think this is a bug and you should open an issue. Given the refusal to construct Tuple{Union{},Union{}} I would agree with that. Otherwise I don’t see how that subtype check is false.

Here’s a confusing one, from the Julia subtyping paper: julia> (Vector{T} where {S,T}){Int} # WAT? Vector{Int64} (alias for Array{Int64, 1}) Naively one would expect for the type application to apply Int to the unused type parameter. However the unused type parameter seems to have already been de…

[image] nsajko: Here’s a confusing one, from the Julia subtyping paper: julia> (Vector{T} where {S,T}){Int} # WAT? Vector{Int64} (alias for Array{Int64, 1}) The unused S is just discarded at runtime: julia> Vector{T} where {S,T} Vector (alias for Array{T, 1} where T) Also occurs in where …

julia> struct A{T,S} end julia> bar(::Union{A{T,2}, A{1,T}}) where T = T julia> bar(A{1,2}()) 1 I think I would prefer if that was an ambiguity error (or at least a warning when running under special command-line flags or debug builds), such as e.g. julia> baz(::A{T,2}) where T = T baz (generic fu…

A most harrowing collection of Julia WATs

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A most harrowing collection of Julia WATs

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