This could be useful to me :) I have a couple of functions that require JuMP but I don't want to add JuMP to my REQUIRE file. My usual tactic of checking isdefined(:JuMP) won't work because JuMP uses macros that are evaluated prior to runtime. However, I was unable to make the following code work:
@cond (isdefined(:JuMP)) begin function something_that_requires_jump(a...) ... end # function end # macro Is there an accepted way to do conditional includes of packages that contain macros? On Thursday, November 12, 2015 at 4:37:43 AM UTC-8, andrew cooke wrote: > > > ah, great. i won't make a new package then. thanks. > > On Thursday, 12 November 2015 09:30:21 UTC-3, Yichao Yu wrote: >> >> https://github.com/JuliaLang/julia/issues/7449 >> https://github.com/JuliaLang/Compat.jl/pull/131 >> https://github.com/JuliaLang/julia/issues/5892 >> >> On Thu, Nov 12, 2015 at 7:23 AM, andrew cooke <and...@acooke.org> wrote: >> > >> > when you're writing code that uses macros, supporting different >> versions of >> > julia seems to be more complex than normal. in particular, things >> like: >> > >> > if VERSION > XX >> > # code with macros here >> > end >> > >> > don't work as expected, because macro expansion occurs before runtime >> > evaluation. so the macros are expenaded whatever version. >> > >> > given that, i have found this simple macro to be useful; >> > >> > macro cond(test, block) >> > if eval(test) >> > block >> > end >> > end >> > >> > @cond VERSION >= v"0.4" begin >> > # code with macros here >> > end >> > >> > anyway, my questions are: (1) is the above sensible and (2) does this >> > already exist? >> > >> > thanks, >> > andrew >> > >> >
