I think I got that much down:
function macroexpand(ex::Expr)
if ex.head == :module
Expr(:module, ex.args[1], ex.args[2], macroexpand(ex.args[3]))
else
macroexpand(ex)
end
end
the issue is that now I want to resolve all imports and such in the module
so that when I expand it, I get properly qualified names for the macros.
so if I had
module M
include("X.jl")
import X: @y, @z
f(x) = X.@y(3)
end
It would still be able to find X.@y.
Evaluating the include/import myself would be kind of risky since someone
could clobber a module name in my global namespace (of the program that's
running to macroexpand this stuff).
Is there a way to sandbox it?
On Monday, March 21, 2016 at 1:00:01 PM UTC-7, Yichao Yu wrote:
>
> On Mon, Mar 21, 2016 at 3:57 PM, <[email protected] <javascript:>>
> wrote:
> > So there's no way to macroexpand the module in the module scope itself?
> > I don't mind evaluating the module, but how do I then dump out the
> > macroexpanded version of it?
> >
> > If there's a way to "clear" global scope then it would also be possible
> to
> > eval the module, expand in global scope, clean global scope,
> rinse/repeat on
> > next module.
> > Is there a way to do that instead?
> >
>
> If you want to just repeat what the global interpreter is doing, you
> can parse the module, create the module yourself, then macroexpand,
> print and evaluate each statement.
>
> >
> > On Monday, March 21, 2016 at 11:55:47 AM UTC-7, Tim Holy wrote:
> >>
> >> 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
> >>
> >
>
