Type piracy with Base.readuntil

[mortenpi]

HTTP.jl/src/IOExtras.jl

Lines 114 to 124 in a3a5768

	function Base.readuntil(buf::IOBuffer,
	find_delimiter::F #= Vector{UInt8} -> Int =#
	)::ByteView where {F <: Function}
	l = find_delimiter(view(buf.data, buf.ptr:buf.size))
	if l == 0
	return nobytes
	end
	bytes = view(buf.data, buf.ptr:buf.ptr + l - 1)
	buf.ptr += l
	return bytes
	end

This could be causing some issues for us in our use case, although that needs a bit more investigation. But regardless, it might be a good idea to try to get rid of it, just in case?

[mortenpi]

I noticed more type piracy in IOExtras:

HTTP.jl/src/IOExtras.jl

Lines 54 to 84 in a3a5768

	if isdefined(Base, :startwrite)
	"$_doc"
	Base.startwrite(io) = nothing
	else
	"$_doc"
	startwrite(io) = nothing
	end
	if isdefined(Base, :closewrite)
	"$_doc"
	Base.closewrite(io) = nothing
	else
	"$_doc"
	closewrite(io) = nothing
	end
	if isdefined(Base, :startread)
	"$_doc"
	Base.startread(io) = nothing
	else
	"$_doc"
	startread(io) = nothing
	end
	if isdefined(Base, :closeread)
	"$_doc"
	Base.closeread(io) = nothing
	else
	"$_doc"
	closeread(io) = nothing
	end

I see it was discussed quite extensively, but never really resolved.

[mortenpi]

So #1083 fixed the readuntil case, but the startread / closeread / startwrite / closewrite functions are still there.

HTTP.jl/src/IOExtras.jl

Lines 46 to 84 in bbe1746

	_doc = """
	startwrite(::IO)
	closewrite(::IO)
	startread(::IO)
	closeread(::IO)
	Signal start/end of write or read operations.
	"""
	@static if isdefined(Base, :startwrite)
	"$_doc"
	Base.startwrite(io) = nothing
	else
	"$_doc"
	startwrite(io) = nothing
	end
	@static if isdefined(Base, :closewrite)
	"$_doc"
	Base.closewrite(io) = nothing
	else
	"$_doc"
	closewrite(io) = nothing
	end
	@static if isdefined(Base, :startread)
	"$_doc"
	Base.startread(io) = nothing
	else
	"$_doc"
	startread(io) = nothing
	end
	@static if isdefined(Base, :closeread)
	"$_doc"
	Base.closeread(io) = nothing
	else
	"$_doc"
	closeread(io) = nothing
	end

Not quite sure how to handle those, since those are exported and/or sometimes extend a Base function.

It seems like IOExtras assumes that they might be defined in Base, although that's only actually true for closewrite. And so HTTP sometimes exports Base.closewrite and sometimes HTTP.IOExtras.closewrite (depending on Julia version). And if it exports Base.closewrite, it does type piracy on it by defining a Base.closewrite(::Any) method. Changing HTTP to always export HTTP.IOExtras.closewrite might be breaking though, since it's also exported from Base.

The other cases are not really a problem though, and we could just remove the isdefined checks. I guess if we really want, we could use a @static if hasmethod() in IOExtras instead, and trust that the trivial fallback methods more or less make sense for other users of the function.