On Mon, Mar 21, 2016 at 2:55 PM, Tim Holy <[email protected]> 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.
Right, it can't for the reason I mentioned (without evaluating the whole module). It can of course, in principle, blindly expand the macro in the current global scope but that won't be what the code is actually doing so I don't think it will be useful. > > 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 >
