David and others: I created a new repo (https://github.com/tbreloff/ModuleSafety.jl) where I'm going to play around with some helper functions/macros to help with to safely use "using" and module-local methods. If anyone wants to brainstorm on useful functionality or contribute, please feel free.
On Friday, May 1, 2015 at 1:40:19 PM UTC-4, David Gold wrote: > > Thank you both, Isaiah and Peter! I'm fairly new to programming and Julia, > and you've both helped along my understanding of Expr objects and macros a > great deal. I thought I'd share my results: > > _ > _ _ _(_)_ | A fresh approach to technical computing > (_) | (_) (_) | Documentation: http://docs.julialang.org > _ _ _| |_ __ _ | Type "help()" for help. > | | | | | | |/ _` | | > | | |_| | | | (_| | | Version 0.3.7 (2015-03-23 21:36 UTC) > _/ |\__'_|_|_|\__'_| | Official http://julialang.org/ release > |__/ | x86_64-apple-darwin13.4.0 > > julia> include("/Users/David/Local projects/metamerge.jl") > makemethod (generic function with 1 method) > > julia> module A > > export f > immutable Foo end > f(::Foo) = print("This is Foo.") > > end > > julia> module B > > export f > immutable Bar end > f(::Bar) = print("This is Bar.") > > end > > julia> f(x::Int64)=x > f (generic function with 1 method) > > julia> metamerge(A.f, A, B.f, B, f) > f (generic function with 3 methods) > > julia> methods(f) > # 3 methods for generic function "f": > f(x::Int64) at none:1 > f(x1::Foo) > f(x1::Bar) > > julia> f(A.Foo()) > This is Foo. > julia> f(B.Bar()) > This is Bar. > julia> f(1) > 1 > > > I've included the code in this gist: > https://gist.github.com/davidagold/cb77a5d9ebb8fa17ee66 --- just in case > anybody is interested. Of course, this doesn't do anything about > conflicting methods, but that functionality shouldn't be hard to add now > that I've gotten the basics of reflection down. > > Thanks again! > David > > > On Thursday, April 30, 2015 at 6:07:28 PM UTC-4, Peter Brady wrote: >> >> Looks like I deleted my post. >> >> If you can include the function name in the macro argument list this >> should work >> >> julia> macro repper(fname, args...) >> ex = Expr(:call, fname) >> for (i, arg) in enumerate(args) >> push!(ex.args, Expr(:(::), symbol("x$i"), arg)) >> end >> ex >> end >> >> julia> (@repper h Int64 Int64) = x1+x2 >> h (generic function with 1 method) >> >> julia> h(1, 2) >> 3 >> >> julia> h(1, 4) >> 5 >> >> >> >> >> On Thursday, April 30, 2015 at 3:19:38 PM UTC-6, David Gold wrote: >>> >>> I'm working (in 3.7) on a function that takes two functions f and g as >>> inputs, merges all non-conflicting methods of f and g into one function h, >>> and returns h. I'm trying to use macros to generate the signatures of each >>> method for h: >>> >>> macro argsgen(typle, n::Int64) >>> y = eval(:($typle)) >>> xn = symbol("x$n") >>> return :( $xn :: $(y[n]) ) >>> end >>> >>> macro repper(typle, n::Int64) >>> ex = "@argsgen($typle, 1)" >>> for i in 2:n >>> ex = string(ex, ", @argsgen($typle, $n)") >>> end >>> >>> return parse(ex) >>> end >>> >>> So, if f has a method with signature (x::Int64), then I can feed the >>> 1-tuple '(Int64,)' to @argsgen, which generates the proper signature: >>> >>> julia> ex1 = macroexpand( :(@argsgen((Int64,), 1) )) >>> :(x1::Int64) >>> >>> and I can thereby define a method for h: >>> >>> >>> julia> h(@argsgen((Int64,), 1)) = x1 + 1 >>> foobar (generic function with 1 method) >>> >>> julia> h(1) >>> 2 >>> >>> The problem is when I try to do this for a signature of more than one >>> argument, say (Int64, Int64). Above I've tried implementing a macro that >>> generates an expression of repeated '@argsgen' calls with the appropriate >>> second argument: >>> >>> ex = macroexpand( :( @repper (Int64, Int64) 2 ) ) >>> :((x1::Int64,x2::Int64)) >>> >>> which doesn't quite work when I attempt to use it for a signature: >>> >>> julia> h(@repper (Int64, Int64) 2) = x1 + x2 >>> ERROR: syntax: "(x1::Int64,x2::Int64)" is not a valid function argument >>> name >>> >>> How can I get @repper to return an expression that isn't a tuple, but >>> also has two @argsgen calls separated by a comma? I've tried a couple of >>> other ways of doing this, but each expression wants to be returned as a >>> tuple. And I can't find out how to make the tuple splat in such a way that >>> works as a signature for h. Any thoughts? (Also, I imagine the tupocalypse >>> will break this, but I can deal with that later.) >>> >>> Thank you all! >>> David >>> >>
