Re: [julia-users] Macro hygiene issue

[Cedric St-Jean]

Thank you, that solved it.

On Wed, Mar 2, 2016 at 10:54 AM, Yichao Yu  wrote:

> On Wed, Mar 2, 2016 at 10:51 AM, Cedric St-Jean 
> wrote:
> > Hi, I have a situation that looks a bit like this:
> >
> > module A
> > function foo end
> > end
> >
> > module B
> > import A: foo
> > macro define_foo(typ, value)
> > :(foo(::$(esc(typ))) = $(esc(value)))
> :(A.foo(...) = ...)
> > end
> > end
> >
> > module C
> > using B: @define_foo
> > @define_foo Int 19
> > end
> >
> > A.foo(20)
> >
> > In other words, A is defining a function foo, B defines a macro to define
> > methods of foo, and C uses the macro. This looks like it should work,
> but it
> > doesn't, because hygiene takes over and `foo` gets replaced with a
> gensym in
> > its expansion, since it's on the left-hand-side of an equality. Is there
> any
> > way around this?
>

Re: [julia-users] Macro hygiene issue

[Yichao Yu]

On Wed, Mar 2, 2016 at 10:51 AM, Cedric St-Jean  wrote:
> Hi, I have a situation that looks a bit like this:
>
> module A
> function foo end
> end
>
> module B
> import A: foo
> macro define_foo(typ, value)
> :(foo(::$(esc(typ))) = $(esc(value)))
:(A.foo(...) = ...)
> end
> end
>
> module C
> using B: @define_foo
> @define_foo Int 19
> end
>
> A.foo(20)
>
> In other words, A is defining a function foo, B defines a macro to define
> methods of foo, and C uses the macro. This looks like it should work, but it
> doesn't, because hygiene takes over and `foo` gets replaced with a gensym in
> its expansion, since it's on the left-hand-side of an equality. Is there any
> way around this?

[julia-users] Macro hygiene issue

[Cedric St-Jean]

Hi, I have a situation that looks a bit like this:

module A
function foo end
end

module B
import A: foo
macro define_foo(typ, value)
:(foo(::$(esc(typ))) = $(esc(value)))
end
end

module C
using B: @define_foo
@define_foo Int 19
end

A.foo(20)

In other words, A is defining a function foo, B defines a macro to define 
methods of foo, and C uses the macro. This looks like it should work, but 
it doesn't, because hygiene takes over and `foo` gets replaced with a 
gensym in its expansion, since it's on the left-hand-side of an equality. 
Is there any way around this?