Support anonymous function in splitdef/combinedef

[tkf]

These examples work now:

https://github.com/MikeInnes/MacroTools.jl/blob/8c003bc25d4298d2305d1ff20af2c0e9c2c013f0/test/split.jl#L58-L70

close #93

[cstjean]

LGTM

I'm not super happy with the exponentially increasing number of branches, though. I wonder if we shouldn't rewrite it as

all_args = kwargs === nothing ? args : Expr(:parameters, kwargs...)
fcall = func === nothing ? args : Expr(:call, func, all_args...)
fcall_with_rtype = rtype === nothing ? fcall : :($fcall::$rtype)
fcall_with_rtype_and_where = ...
etc.

It could be done in another PR. It looks like it could be a lot shorter.

[tkf]

if we shouldn't rewrite it as

It sounds like a great idea. I just tried to stick with the existing pattern.

[MasonProtter]

Perhaps MacroTools.jl should just use https://github.com/invenia/ExprTools.jl for splitdef and combinedef? ExprTools.jl's implementation is a bit more robust and performant from what I understand.

[cstjean]

That's #132

[MasonProtter]

🤦 oops, I should read more carefully.

[devmotion]

Is it possible to tag a release with these changes? I'd like to use this functionality and since I'm already using MacroTools it would be nice to avoid having to add ExprTools (which handles anonymous functions fine) as an additional dependency.