add support for symbols as keys

[alex-s-gardner]

This adds support for symbol indexing into a ZGroup

[coveralls]

Pull Request Test Coverage Report for Build 7008504781

• 1 of 3 (33.33%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.2%) to 87.067%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/ZGroup.jl	1	3	33.33%

Totals
Change from base Build 6484107136:	-0.2%
Covered Lines:	754
Relevant Lines:	866

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💛 - Coveralls

[alex-s-gardner]

Doc errors appear unrelated to this PR

[meggart]

Thanks a lot for preparing this. I just looked at it and really like the idea to make the interface more DataFrame-like. I got carried away a bit and implemented dot syntax for subsetting as well so that you can use g.a to access array "a" from group g. Autocompletion works as well which should make working with groups much more ergonomic. However, this would technically be breaking because an array name might shadow the name of field of ZGroup so I had to define some accessors to disambiguate.

Could you have a look if this works for you?

[coveralls]

Pull Request Test Coverage Report for Build 7043631258

• 47 of 56 (83.93%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.09%) to 87.177%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/ZGroup.jl	33	42	78.57%

Files with Coverage Reduction	New Missed Lines	%
src/ZGroup.jl	1	84.16%

Totals
Change from base Build 6484107136:	-0.09%
Covered Lines:	775
Relevant Lines:	889

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 7113230225

• 55 of 55 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.2%) to 88.501%

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Totals
Change from base Build 6484107136:	1.2%
Covered Lines:	785
Relevant Lines:	887

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💛 - Coveralls

[alex-s-gardner]

in the depths of AGU prep right now but will review this asap

[alex-s-gardner]

This is fantastic!!! I took the changes for a quick spin and everything was intuitive and worked as expected. I see use of "z.metadata" which I think now needs to be removed and a "metadata()" function likely needs to be added.

[alex-s-gardner]

does z.metadata.chunks need to be updated now that we have . inexing

[meggart]

I don't think so. It is only ZGroups that have the new . indexing where we need to be careful, ZArrays would still behave the same

[alex-s-gardner]

does z.metadata.order need to be updated now that we have . inexing

[alex-s-gardner]

same comment for all occurrences ofz.metadata

[asinghvi17]

Adding a metadata function is a bit tricky, since one could mean either .zattrs or .zarray by "metadata".

The simplest solution would be to replace all z.metadata with getfield(z, :metadata) but that would make attribute inspection in general very hard. Some function to get .zarray attributes would be best, but I'm not sure what that is.