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
>
>
