WIP: Get fieldtypes from defaults

[mauro3]

Resolves #131

julia> @with_kw struct MT5{I}                                                                                                                                                                   
           r::typeof=5                                                                                                                                                                          
           a::I                                                                                                                                                                                 
       end                                                                                                                                                                                      
MT5                                                                                                                                                                                             
                                                                                                                                                                                                
julia> MT5(5.5, 1)                                                                                                                                                                              
ERROR: InexactError: Int64(5.5)                                                                                                                                                                 
Stacktrace:                                                                                                                                                                                     
 [1] Int64 at ./float.jl:710 [inlined]                                                                                                                                                          
 [2] convert at ./number.jl:7 [inlined]                                                                                                                                                         
 [3] MT5 at /home/mauro/julia/dot-julia-dev/Parameters/src/Parameters.jl:489 [inlined]                                                                                                          
 [4] MT5(::Float64, ::Int64) at /home/mauro/julia/dot-julia-dev/Parameters/src/Parameters.jl:512                                                                                                
 [5] top-level scope at REPL[3]:1                                                                                                                                                               
                                                                                                                                                                                                
julia> MT5(5, 1)                                                                                                                                                                                
MT5{Int64}                                                                                                                                                                                      
  r: Int64 5                                                                                                                                                                                    
  a: Int64 1                                                                                                                                                                                    

and

julia> @with_kw struct MT2 @deftype typeof
           r=5
           a
       end
MT2

julia> MT2(4.5,1)
ERROR: InexactError: Int64(4.5)
Stacktrace:
 [1] Int64 at ./float.jl:710 [inlined]
 [2] convert at ./number.jl:7 [inlined]
 [3] MT2(::Float64, ::Int64) at /home/mauro/julia/dot-julia-dev/Parameters/src/Parameters.jl:489
 [4] top-level scope at REPL[3]:1

julia> MT2(4,1)
MT2
  r: Int64 4
  a: Int64 1

[codecov]

Codecov Report

Merging #138 (ecbf8df) into master (cf8fec6) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #138   +/-   ##
=======================================
  Coverage   93.66%   93.66%           
=======================================
  Files           1        1           
  Lines         284      284           
=======================================
  Hits          266      266           
  Misses         18       18           

Impacted Files	Coverage Δ
src/Parameters.jl	93.66% <100.00%> (ø)

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[bgroenks96]

So it isn't working for me, but I think it's because Julia is somehow not using the updated version (error line numbers don't make sense).

What is the general best practice for doing this? I initially did develop ... on my fork and then checked out the branch. But even after doing activate . it didn't seem to recompile Parameters.jl. Same thing happens when I do add <url>#m3/typeof. So I'm a bit at a loss how to get Julia to recompile and/or use the right version without deleting my entire .julia folder and starting from scratch...

[mauro3]

You first create a dev of Parameters. E.g. start the repl and do ], dev Parameters. That will create ~/.julia/dev/Parameters, a git repo. quit the repl, cd to ~/.julia/dev/Parameters, do git checkout m3/typeof. Starting as julia --project should get your repl started with Parameters as active project. Probably start with ] and test to see whether test currently pass. Then start edidting. Once you want to commit, maybe make a new branch git checkout -b bt/typeof-addons, git commit -am "...". The add your fork as remote git remote add bgroenks96 ...url..., then git push bgroenks96. The open the PR.

Does that help?

[bgroenks96]

Hi @mauro3 . Sorry for the long delay on this... I got caught up in other things.

I am of course familiar with git and everything, that's not so much the issue. The issue was just that julia didn't seem to recompile Parameters, or was for some reason using the wrong version, I still don't really know. I set everything up on a separate machine with a clean environment and now it works. I am working on tests now!

[bgroenks96]

@mauro3 So far so good except for one somewhat contrived issue with @deftype and field-dependent default values:

@with_kw struct I131c @deftype typeof
    a = 5
    b = 1.0
    c = a + b
end

throws error ERROR: LoadError: UndefVarError: a not defined.

Like I said, this is somewhat contrived, and one workaround is to just explicitly declare the type ::Float64 on c. We could just document this and open a new issue for later, unless you have a quick fix in mind...?

[mauro3]

Ok, that is a good catch. It might be a bit hard to support this, I'll see.