Julia: Incorrect method counting after function redefinition.

[SalchiPapa]

This is appreciated just when showing the function, methods(f) is correct:

julia> foo() = :foo
foo (generic function with 1 method)

julia> foo() = :foo
WARNING: Method definition foo() in module Main at REPL[56]:1 overwritten at REPL[56]:1.
foo (generic function with 2 methods)

julia> foo() = :foo
WARNING: Method definition foo() in module Main at REPL[56]:1 overwritten at REPL[56]:1.
foo (generic function with 3 methods)

julia> foo() = :foo
WARNING: Method definition foo() in module Main at REPL[56]:1 overwritten at REPL[56]:1.
foo (generic function with 4 methods)

julia> methods(foo)
# 1 method for generic function "foo":
foo() in Main at REPL[56]:1

julia> foo
foo (generic function with 4 methods)

julia> VERSION
v"0.6.0-dev.1781"

[yuyichao]

This isn't wrong. The four are all callable

[SalchiPapa]

But it's misleading that display says one thing and methods another. Maybe we need to tell it has 1 method with 4 versions?

julia> methods(foo)
# 1 method for generic function "foo":
foo() in Main at REPL[56]:1

julia> foo
foo (generic function with 1 method and 4 versions)

Something like that makes more sense to me IMHO.

[nalimilan]

This isn't wrong. The four are all callable

How can they be called?

[yuyichao]

How can they be called?

If some code was executing in the corresponding world, calling foo in that world will run the corresponding method.

[JeffBezanson]

I also think this is a bug. Calling methods(f) implicitly passes a world number, and the result is for that world. The method count should use the equivalent of length(methods(f)). The default behavior should be to give results for a specific default world.

[vtjnash]

would you object to us instead always printing the world counter:

# 1 method for generic function "foo" *in the current world*:
# 1 method for generic function "foo" *in world 12345*:

Altering the count to exclude methods with max-age cutoffs shouldn't be hard either.

[JeffBezanson]

I think "in the current world" should be the default, and therefore implied, so it doesn't need to be printed.

[dpsanders]

Is there documentation about worlds somewhere?

[SalchiPapa]

@dpsanders there is a new Redefining Methods subject in the Methods chapter of the manual:

• https://github.com/JuliaLang/julia/blob/master/doc/src/manual/methods.md#redefining-methods

[stevengj]

Closed by #19889.