$ is variable interpolation inside macros, thus I don't think you can
also do string interpolation (which also uses $) inside macros. But
something like this should work:
julia> macro A(str)
esc(quote
a=5
b=7
c=$str*".tmp"
end)
end
julia> @A("myfile")
"myfile.tmp"
julia> c
"myfile.tmp"
Note that if you didn't `esc` the whole macro (which is the usual case),
then you'd write `$(esc(str))` inside the macro to get to the variable.
On Thu, 2014-06-26 at 22:57, [email protected] wrote:
> Just to be clear: I’m aware that there’s probably no way to get this
> working with e.g. any string variable. But I don’t see a reason why it
> shouldn’t be possible when passing a constant, or especially a literal
> constant, to the macro, such as with @foo("bar") (rather than bar="bar";
> @foo(bar), which I understand might be impossible).
>
> // T
>
> On Thursday, June 26, 2014 11:54:55 PM UTC+2, Tomas Lycken wrote:
>
> This gets me quite far - thanks a lot! However, to make it work, I have to
>> hard-code the value of datafile, since I can’t figure out how to get the
>> macro to create the string "$datafile.jld" correctly. This is probably OK
>> for my use case - I only have two datafiles, so I can create two macros :P
>> But it would be nice to learn how to do it, if it’s possible.
>>
>> Basically, is there a way to make the following work?
>>
>> @macro foo(bar)
>> esc(quote
>> "$bar.baz"
>> end)
>> end
>>
>> Currently @foo("fizz") is just the string literal "$bar.baz".
>>
>> // T
>>
>> On Thursday, June 26, 2014 9:25:18 PM UTC+2, Mauro wrote:
>>
>> Maybe something like this should work:
>>>
>>> julia> macro A()
>>> esc(quote
>>> a=5
>>> b=7
>>> end)
>>> end
>>>
>>> julia> function f(x)
>>> @A
>>> x+a+b
>>> end
>>> f (generic function with 1 method)
>>>
>>> julia> f(5)
>>> 17
>>>
>>> If you don't want your variable names to be mangled then do the `esc`.
>>>
>>> So, basically just write normal code in the `esc(quote ... end)` bit.
>>>
>>> On Thu, 2014-06-26 at 19:21, [email protected] wrote:
>>> > That explains it, thanks.
>>> >
>>> > In my actual problem, what I wanted to do in the included file was
>>> > something like this:
>>> >
>>> > ```
>>> > sall,sloops,slost,Nbins,psibins,initialhist,finalhist,vols =
>>> > jldopen("$datafile.jld") do f
>>> > read(f, "sall"),
>>> > read(f, "sloops"),
>>> > read(f, "sloss"),
>>> > read(f, "Nbins"),
>>> > read(f, "psibins"),
>>> > read(f, "initialhist"),
>>> > read(f, "finalhist"),
>>> > read(f, "vols")
>>> > end
>>> > ```
>>> >
>>> > where `datafile` is the variable defined in the function. In other
>>> words,
>>> > including the file would define and assign to all those variables. Is
>>> it
>>> > maybe possible to write a macro that does this?
>>> >
>>> > // T
>>> >
>>> > On Thursday, June 26, 2014 8:17:29 PM UTC+2, Simon Kornblith wrote:
>>> >>
>>> >> include evaluates at top-level, so this would only work if foo were a
>>> >> global variable. It not possible to include in a function context for
>>> the
>>> >> same reason it is not possible to eval in a function context.
>>> >>
>>> >> Simon
>>> >>
>>> >> On Thursday, June 26, 2014 1:03:00 PM UTC-4, Tomas Lycken wrote:
>>> >>>
>>> >>> I have the following two files:
>>> >>>
>>> >>> *includetest1.jl*:
>>> >>>
>>> >>> module IncludeTest
>>> >>>
>>> >>> function testinclude()
>>> >>> foo = "foo"
>>> >>> println(foo)
>>> >>> include("includetest2.jl")
>>> >>> end
>>> >>>
>>> >>> end
>>> >>>
>>> >>> *includetest2.jl*
>>> >>>
>>> >>> println(foo)
>>> >>>
>>> >>> If I now try to execute this the function from the REPL, I get errors
>>> >>> stating that foo is not defined:
>>> >>>
>>> >>> julia> include("includetest1.jl")
>>> >>>
>>> >>> julia> IncludeTest.testinclude()
>>> >>> foo
>>> >>> ERROR: foo not defined
>>> >>> in include at boot.jl:244
>>> >>> while loading [...]/includetest2.jl, in expression starting on line 1
>>> >>>
>>> >>> I thought include was supposed to just insert the contents of the
>>> file
>>> >>> in whatever context you’re in? If include is not the way to do this,
>>> is
>>> >>> there another?
>>> >>>
>>> >>> For completeness:
>>> >>>
>>> >>>
>>> >>> julia> versioninfo()
>>> >>> Julia Version 0.3.0-prerelease+3884
>>> >>> Commit 3e6a6c7* (2014-06-25 10:41 UTC)
>>> >>> Platform Info:
>>> >>> System: Linux (x86_64-linux-gnu)
>>> >>> CPU: Intel(R) Core(TM) i7-2630QM CPU @ 2.00GHz
>>> >>> WORD_SIZE: 64
>>> >>> BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY)
>>> >>> LAPACK: libopenblas
>>> >>> LIBM: libopenlibm
>>> >>>
>>> >>> // T
>>> >>>
>>> >>>
>>> >>
>>>
>>> --
>>>
>>>
>>
>
--
