> On 31 Jul 2024, at 06:10, Kevin Pye <kjpr...@pye.id.au> wrote: > > I am trying to build a replacement for the existing Physics::Constants > module, but running into problems when loading the pre-compiled version. I > want to use code like: > > unit module Physics::Constants; > > use Physics::Unit; > use Physics::Measure; > > constant \avogadro-constant is export(:DEFAULT, :fundamental, > :avogadro-constant) = Measure.new( > value => 6.02214076e+23, > error => 0, > units => 'mol⁻¹', > ); > > which compiles and runs quite well. However, when I try to run "mi6 test" > which will precompile and then load the code, I get the following output: > > $ mi6 test > ===SORRY!=== Error while compiling > /home/kevin/git/Physics-Constants/t/01-basic.rakutest > ===SORRY!=== Error while compiling > /home/kevin/git/Physics-Constants/lib/Physics/Constants.rakumod > (Physics::Constants) > An exception X::Comp::AdHoc occurred while evaluating a constant: > Cannot unbox a P6opaque (NQPMu) type object > at /home/kevin/git/Physics-Constants/lib/Physics/Constants.rakumod > (Physics::Constants):6 > Exception details: > ===SORRY!=== Error while compiling > Cannot unbox a P6opaque (NQPMu) type object > at line > > at .../Physics-Constants/t/01-basic.rakutest:2 > t/01-basic.rakutest .. Dubious, test returned 1 > No subtests run > > I am guessing that it can't deserialize the serialized Physics::Measure > object, but I could be quite wrong.
This appears to be an issue with resolving somewhere deep in the bowels. In RakuAST, the error is slightly more clear: ===SORRY!=== Cannot look up attributes in a RakuAST::Resolver type object. Did you forget a '.new'? I'm pretty sure we won't fix this in the legacy grammar. I'll be looking at fixing this in RakuAST. Meanwhile, I would also suggest making this an issue in the Physics::Measure repo https://github.com/librasteve/raku-Physics-Measure so that the author is alerted to this problem, and maybe can figure out what tickles it. > Any ideas on how to make this work? Put this in lib/Physics/Constants.rakumod: ===================== use Physics::Unit; use Physics::Measure; my $avogadro-constant := Measure.new( value => 6.02214076e+23, error => 0, units => 'mol⁻¹', ); sub EXPORT { Map.new: (:$avogadro-constant) # must have () to force positional Pair } ===================== And then run: $ raku -Ilib -MConstants -e 'say avogadro-constant' 6.02214076e+23mol⁻¹ ±0 In other words: drop the module statement. The namespace *from* which you export constants, is usually not important. And use an EXPORT sub (https://docs.raku.org/syntax/sub%20EXPORT) to export whatever values that were created when the mainline of the module runs. Disadvantages to this approach: - you lose the standard capability to selective importing - the constants are created at module load time, and not serialized HTH, Liz
