[MISC] Change value_list_validator construction.

[smehringer]

Part of #1196

I noticed that you cannot construct a value_list_validator from a simple range (only from a vector or initialiser list). I added construction from a range, as well as construction from a parameter pack which makes initialiser lists obsolete, but this is an API break. @seqan/core Should I still provide an initialiser list constructor?

Also: where in the changelog did we report API changes?

// What worked before and still works now:
std::vector<int> v{0, 1, 2};
seqan3::value_list_validator{v}; // l/rvalue std::vector 

// What works now that hasn't worked before:
seqan3::value_list_validator{0, 1, 2}; // parameter pack
seqan3::value_list_validator{v | views::take(2)}; // ranges/views

// What worked before but does not work anymore:
seqan3::value_list_validator{{0, 1, 2}}; // initialiser list

[h-2]

I added construction from a range, as well as construction from a parameter pack which makes initialiser lists obsolete, but this is an API break.

Why is it an API break? If the range interface accepts anything that was accepted before and has the same semantics, the API is preserved. We explicitly state that people may not rely on the exact signature, only on the implied semantics.

[smehringer]

Sorry, I added some examples for clarity. There is a syntax break since I cannot use {{...}} anymore. I thought this was ugly anyway so since we are not API stable yet I would like to remove this version.

[smehringer]

@seqan/core ping

[rrahn]

I just looked into it to get an overview of the implied changes. Found some things

[codecov]

Codecov Report

Merging #1298 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1298      +/-   ##
==========================================
+ Coverage   97.41%   97.41%   +<.01%     
==========================================
  Files         216      216              
  Lines        8671     8675       +4     
==========================================
+ Hits         8447     8451       +4     
  Misses        224      224

Impacted Files	Coverage Δ
include/seqan3/argument_parser/validators.hpp	88.69% <100%> (+0.27%)	⬆️

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[eseiler]

This explanation could also go into the class docs. I was actually wondering why it's double for all arithmetic types...

[rrahn]

In general these files seem not to follow our style guide which they actually should but that is for another time. It seems we need to go through the tutorials anyway before the release. But maybe you can mark it already as a card so we do not forget about it.

[smehringer]

which style do you mean specifically?

[rrahn]

the all-or-nothing rule:
if you break on a line, then put every argument on a separate line

parser.add_option(args.aggregate_by, 
                  'a', 
                  "aggregate-by", 
                  "Choose your method of aggregation.",
                  option_spec::DEFAULT, 
                  value_list_validator{{"median", "mean"}});