HDF5 high-level wrapper for nested Dicts

General Usage
,
3

Here’s my version of how I write this taking advantage of multiple dispatch.

julia> function write_dicts_to_hdf5_groups(
           parent::Union{HDF5.File, HDF5.Group},
           dict::Dict
       )
           for (key, value) in dict
               write_dicts_to_hdf5_groups(parent, key, value)
           end
       end
write_dicts_to_hdf5_groups (generic function with 3 methods)

julia> function write_dicts_to_hdf5_groups(
           parent::Union{HDF5.File, HDF5.Group},
           key::AbstractString,
           dict::Dict
       )
           group = create_group(parent, key)
           write_dicts_to_hdf5_groups(group, dict)
       end
write_dicts_to_hdf5_groups (generic function with 3 methods)

julia> function write_dicts_to_hdf5_groups(
           parent::Union{HDF5.File, HDF5.Group},
           key::AbstractString,
           value
       )
           write(parent, key, value)
       end
write_dicts_to_hdf5_groups (generic function with 3 methods)

julia> h5open("allthestuff.h5", "w") do h5f
           write_dicts_to_hdf5_groups(h5f, allthestuff)
       end

julia> run(`h5ls -r allthestuff.h5`)
/                        Group
/a                       Dataset {9}
/e                       Group
/e/medium                Group
/e/medium/epsilon        Dataset {SCALAR}
/e/medium/mu             Dataset {SCALAR}
/e/particle              Group
/e/particle/epsilon      Dataset {SCALAR}
/e/particle/mu           Dataset {SCALAR}
/g                       Group
/g/a                     Dataset {SCALAR}
/g/c                     Dataset {SCALAR}
/g/shape                 Dataset {SCALAR}
/m                       Dataset {9, 30, 30}
Process(`h5ls -r allthestuff.h5`, ProcessExited(0))

Another approach here would be to encode the dict as a compound datatype. Basically convert the Dict to a NamedTuple and then write that.

Dicts are hard to read and write since we do not know the type of the members up front. A NamedTuple is fully typed.

A big question is if there is a large array somewhere in the tree then the current approach would be better.