@Scott: Glad to hear it may be useful to you! If you encounter any bugs, or
if you think of a related feature you'd like to see, please do open an
issue in the github repo. I'll try my best to accommodate.
@Sisyphuss: As Stefan notes, this is an additional feature. I intend it to
complement the fix in issue #4345, which actually provides the cleanest
environment for using merge!().
As soon as I figure out git I will be able to turn this into a real
package. I intend for that to happen asap.
D
On Tuesday, May 5, 2015 at 8:31:17 AM UTC-4, Scott Jones wrote:
>
> Great! +1 This will solve a lot of my problems about trying to maintain
> good software engineering practices with Julia, (but not all, it doesn't
> address being able to keep the implementation separate from the
> abstraction...
> I really don't want others to have the ability to play with my private
> parts [as somebody else here so aptly put it])
>
> Scott
>
> On Monday, May 4, 2015 at 3:08:43 PM UTC-4, David Gold wrote:
>>
>> Based on recent discussions, it seems that at least some people would
>> like the option to have unqualified use of a function name dispatch
>> "across" modules when the argument on which the function is called
>> unambiguously specifies an exported method. While Julia doesn't do this
>> automatically, one option is for the user explicitly to "merge" functions
>> defined in different modules. I've been working on an implementation of
>> this functionality that doesn't require users to copy a bunch of method
>> definitions:
>>
>> julia> using MetaMerge
>>
>> julia> f() = nothing
>> f (generic function with 1 method)
>>
>> julia> module A
>>
>> export f
>> immutable Foo end
>> f(::Foo) = print("This is Foo.")
>> f(x::Int64) = x
>>
>> end
>>
>> julia> module B
>>
>> export f
>> immutable Bar end
>> f(::Bar) = print("This is Bar.")
>> f(x::Int64) = 2x
>>
>> end
>>
>> julia> using A, B
>> Warning: using A.f in module Main conflicts with an existing identifier.
>> Warning: using B.f in module Main conflicts with an existing identifier.
>>
>> julia> methods(f)
>> # 1 method for generic function "f":
>> f() at none:1
>>
>> julia> merge!(f, (A,f), (B,f))
>>
>> julia> methods(f)
>> # 3 methods for generic function "f":
>> f() at none:1
>> f(x1::Foo)
>> f(x1::Bar)
>>
>> julia> f(A.Foo())
>> This is Foo.
>> julia> f(B.Bar())
>> This is Bar.
>>
>>
>> One can also use merge!() while writing modules to allow for unqualified
>> use of a name within the module, such as in the definition of h below:
>>
>> julia> module C
>>
>> export f
>> using MetaMerge, A, B
>> f(::Union()) = nothing
>> merge!(f, (A,f), (B,f), conflicts_favor=A)
>> h(x::Int64) = f(x)
>>
>> end
>>
>> julia> using C
>> Warning: using C.f in module Main conflicts with an existing identifier.
>>
>> julia> C.h(2)
>> 2
>>
>>
>> The repo is here: https://github.com/davidagold/MetaMerge.jl (I've never
>> versioned anything before, so I apologize in advance if the numbers seem
>> silly/arbitrary). I hope it can be useful to some. Folks should feel free
>> to leave suggestions, bug reports or requests for other kinds of
>> functionality that they'd like to see from something like this. I'll do my
>> best to accommodate, though I'm rather new to programming and hence cannot
>> make any promises.
>>
>> Cheers,
>> David
>>
>
