Add convert method to `Dictionary`

[serenity4]

This implements a very basic method to automatically convert between Dictionary types. I am not sure whether there is anything more to do.

Solves #66.

[codecov[bot]]

Codecov Report

Merging #67 (eadc8af) into master (03d79e4) will increase coverage by 0.90%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #67      +/-   ##
==========================================
+ Coverage   74.02%   74.93%   +0.90%     
==========================================
  Files          19       19              
  Lines        1721     1871     +150     
==========================================
+ Hits         1274     1402     +128     
- Misses        447      469      +22     

Impacted Files	Coverage Δ
src/Dictionary.jl	67.71% <100.00%> (+3.36%)	:arrow_up:
src/Indices.jl	87.97% <0.00%> (-0.49%)	:arrow_down:
src/find.jl	100.00% <0.00%> (ø)
src/insertion.jl	71.00% <0.00%> (+0.19%)	:arrow_up:
src/AbstractIndices.jl	78.53% <0.00%> (+0.21%)	:arrow_up:
src/filter.jl	63.20% <0.00%> (+0.26%)	:arrow_up:
src/show.jl	93.75% <0.00%> (+0.41%)	:arrow_up:
src/ArrayIndices.jl	96.47% <0.00%> (+0.58%)	:arrow_up:
src/broadcast.jl	51.38% <0.00%> (+0.61%)	:arrow_up:
src/map.jl	44.32% <0.00%> (+0.80%)	:arrow_up:
... and 8 more

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[serenity4]

Yes, it would be nice to make it work for all types of dictionaries. I'm not sure if there is a generic way to do it on AbstractDictionary that could work regardless of the implementation, though it might be reasonable to have a default conversion behavior that can be customized for dictionary implementations.

[andyferris]

I know in Base there are methods like convert(::Type{AbstractVector{T}}, v::Vector) where {T} = Vector{T}(v). I think we could do that kind of thing here? I'm happy to merge this now and address it in the future though.

[andyferris]

FYI https://github.com/JuliaRegistries/General/pull/45174

[serenity4]

Thanks! Indeed there might be a way to do it cleanly. I personally needed this for Dictionary at the moment, but I'd be happy to revisit that in the future if needed.