simplify union

[aplavin]

[codecov[bot]]

Codecov Report

Merging #113 (52d628e) into master (b3f0d6e) will decrease coverage by 0.16%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #113      +/-   ##
==========================================
- Coverage   98.81%   98.64%   -0.17%     
==========================================
  Files           3        3              
  Lines         253      222      -31     
==========================================
- Hits          250      219      -31     
  Misses          3        3              

Impacted Files	Coverage Δ
src/interval.jl	98.86% <100.00%> (-0.30%)	:arrow_down:

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[aplavin]

Anything wrong with this PR? It nicely gets rid of all those special cases.

Behavior doesn't change at all, as evidenced by no test changes. Just stumbled across this piece of code when fixing https://github.com/JuliaMath/IntervalSets.jl/pull/112.

[hyrodium]

I have checked some benchmarks, there weren't any degressions. I found some type instability, but this is the same behavior as on the current master.

julia> @code_warntype (1 .. 3) ∪ (2.0 .. 5.0)
MethodInstance for union(::ClosedInterval{Int64}, ::ClosedInterval{Float64})
  from union(d1::IntervalSets.TypedEndpointsInterval, d2::IntervalSets.TypedEndpointsInterval) in IntervalSets at /home/hyrodium/.julia/dev/IntervalSets/src/interval.jl:126
Arguments
  #self#::Core.Const(union)
  d1::ClosedInterval{Int64}
  d2::ClosedInterval{Float64}
Body::Union{ClosedInterval{Float64}, ClosedInterval{Int64}}
1 ── %1  = IntervalSets.isempty(d1)::Bool
└───       goto #3 if not %1
2 ──       return d2
3 ── %4  = IntervalSets.isempty(d2)::Bool
└───       goto #5 if not %4
4 ──       return d1
5 ── %7  = (∈)(d1)::Base.Fix2{typeof(in), ClosedInterval{Int64}}
│    %8  = IntervalSets.endpoints(d2)::Tuple{Float64, Float64}
│    %9  = IntervalSets.any(%7, %8)::Bool
└───       goto #7 if not %9
6 ──       goto #10
7 ── %12 = (∈)(d2)::Base.Fix2{typeof(in), ClosedInterval{Float64}}
│    %13 = IntervalSets.endpoints(d1)::Tuple{Int64, Int64}
│    %14 = IntervalSets.any(%12, %13)::Bool
└───       goto #9 if not %14
8 ──       goto #10
9 ── %17 = IntervalSets.ArgumentError("Cannot construct union of disjoint sets.")::Any
└───       IntervalSets.throw(%17)
10 ┄ %19 = IntervalSets._union(d1, d2)::ClosedInterval{Float64}
└───       return %19

Note that there is no this type instability with intersect.