Interesting. julia's `macroexpand` function doesn't seem to work for
expressions inside a module:
julia> macroexpand( :(module M @time(1+1) end))
:(module M
eval(x) = begin # none, line 1:
top(Core).eval(M,x)
end
eval(m,x) = begin # none, line 1:
top(Core).eval(m,x)
end # none, line 1:
@time 1 + 1
end)
which is the same thing you get back if you omit the `macroexpand`.
Try commenting out the module declaration and see if you like it better.
Best,
--Tim
On Monday, March 21, 2016 11:15:56 AM [email protected] wrote:
> The MacroExpandJL package seems promising, but maybe I'm not able to get it
> to work. After updating syntax to match julia 0.4,
> MacroExpandJL.macroexpand_jl(STDOUT, :(module M function f(x) 1+@m(2) end
> end))
> module M
> begin # line 1:
> function f(x) # line 1:
> 1 + @m 2
> end
> endend
>
> Notice how the @m 2 is still there. Also, why is everything wrapped in an
> extra do block inside the module? Is this a printing issue, because that
> expression doesn't have one.
>
> How would I go about evaluating a module and it's macros, macro expanding
> the whole thing, and then dumping it out? @eval seems like, name wise, it
> should do this but it doesn't.
> Do you first eval() the module, then @eval the module? That didn't work for
> me either.
>
> Predefining a macro and then trying to evaluate:
> > macro m(x) 1 end
> > @eval(:(module M function f(x) @m 2 end end))
> :
> :(module M
>
> eval(x) = begin # none, line 1:
> top(Core).eval(M,x)
> end
> eval(m,x) = begin # none, line 1:
> top(Core).eval(m,x)
> end # none, line 1:
> function f(x) # none, line 1:
> @m 2
> end
> end)
>
> Also doesn't work.
>
> On Monday, March 21, 2016 at 7:54:59 AM UTC-7, Tim Holy wrote:
> > On Monday, March 21, 2016 09:34:19 AM Stefan Karpinski wrote:
> > > Tim, I'm assuming that module must assume that no macros are defined
> >
> > *and*
> >
> > > then used within the module body. If that does occur, the only way to do
> > > macro expansion correctly is to evaluate the module since the module
> > > definition can depend on arbitrary previously evaluated code.
> >
> > Probably true. I haven't played with it in a long time, but it's possible
> > you
> > could load the module (so the macros are defined) and then parse the
> > file...but
> > I can't remember if that works.
> >
> > Best,
> > --Tim
> >
> > > On Sun, Mar 20, 2016 at 9:00 PM, Tim Holy <[email protected]
> >
> > <javascript:>> wrote:
> > > > It probably needs updating, but
> > > > https://github.com/timholy/MacroExpandJL.jl
> > > > might help. It lets you macroexpand a whole source file.
> > > >
> > > > Best,
> > > > --Tim
> > > >
> > > > On Sunday, March 20, 2016 08:53:49 PM Yichao Yu wrote:
> > > > > On Sun, Mar 20, 2016 at 8:26 PM, <[email protected]
> > > > > <javascript:>>
> >
> > wrote:
> > > > > > Hi all,
> > > > > >
> > > > > > I'd like to be able to load in a module, then macroexpand the
> >
> > whole
> >
> > > > thing,
> > > >
> > > > > > then print out the macroexpanded version.
> > > > > >
> > > > > > This should be a full, recursive macroexpand.
> > > > > >
> > > > > > I've noticed there is a function called macroexpand that normally
> >
> > does
> >
> > > > > > what
> > > > > >
> > > > > > i want:
> > > > > >> macro m(x) 1 end
> > > > > >
> > > > > > ..
> > > > > >
> > > > > >> @m(2)
> > > > > >
> > > > > > 1
> > > > > >
> > > > > >> macroexpand(:(1 + @m(2)))
> > > > > >>
> > > > > > :(1 + 1)
> > > > > >
> > > > > > so that is fine and dandy, but inside a module this doesn't seem
> >
> > to
> >
> > > > work:
> > > > > >> macroexpand(:(
> > > > > >>
> > > > > > module M
> > > > > > macro m(x) 1 end
> > > > > > x = 1 + @m(2)
> > > > > > end
> > > > > > ))
> > > > > > :
> > > > > > :(module M
> > > > > > :
> > > > > > eval(x) = begin # none, line 2:
> > > > > > top(Core).eval(M,x)
> > > > > >
> > > > > > end
> > > > > >
> > > > > > eval(m,x) = begin # none, line 2:
> > > > > > top(Core).eval(m,x)
> > > > > >
> > > > > > end # none, line 3:
> > > > > > $(Expr(:macro, :(m(x)), quote # none, line 3:
> > > > > > 1
> > > > > >
> > > > > > end)) # none, line 4:
> > > > > > x = 1 + @m(2)
> > > > > > end)
> > > > > >
> > > > > > As you can see in the second to last line, @m(2) is not expanded,
> >
> > and
> >
> > > > I'm
> > > >
> > > > > > confused as to why that is.
> > > > > >
> > > > > > Ideally, this macroexpanding of a module would allow me to also
> > > > > > resolve
> > > > > > imports and includes properly, so I could just slurp up a file and
> > > > > > dump
> > > > > > out
> > > > > > the macroexpanded version.
> > > > >
> > > > > TL;DR this is generally not possible without evaluating the whole
> > > > > module.
> > > > >
> > > > > Macros are executed at parse time and therefore resolved in global
> > > > > scope (since local scope doesn't even exist yet) or in another word
> > > > > module scope.
> > > > > Therefore when doing macro expansion in a new module, the macros
> >
> > needs
> >
> > > > > to be resolved in the new module and since there's no way to
> > > > > statically know what macros are available in a module you can't do
> > > > > that without evaluating the module.
> > > > >
> > > > > > Thank you!
> > > > > >
> > > > > > Vishesh
