Skip to content

add more methods and tests for reductions over empty arrays #29919

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
vtjnash merged 7 commits into from
Nov 2, 2023
Merged

add more methods and tests for reductions over empty arrays #29919

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
164e0da
add more methods and tests for reductions over empty arrays
simonbyrne Nov 3, 2018
61565c4
Merge branch 'master' into sb/reduce-empty
vtjnash Apr 9, 2021
41706b3
Update base/reduce.jl
vtjnash Apr 9, 2021
10880a3
Update base/reduce.jl
simonbyrne Nov 23, 2021
c4bfbc2
Update base/reduce.jl
simonbyrne Nov 23, 2021
d1cdd53
Update base/reduce.jl
simonbyrne Nov 23, 2021
129aeb5
Merge branch 'master' into sb/reduce-empty
simonbyrne Nov 23, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 7 additions & 2 deletions base/reduce.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -318,6 +318,9 @@ reduce_empty(::typeof(*), ::Type{<:AbstractChar}) = ""
reduce_empty(::typeof(&), ::Type{Bool}) = true
reduce_empty(::typeof(|), ::Type{Bool}) = false

reduce_empty(::typeof(max), T::Type{<:AbstractFloat}) = typemin(T)
reduce_empty(::typeof(min), T::Type{<:AbstractFloat}) = typemax(T)

reduce_empty(::typeof(add_sum), ::Type{Union{}}) = _empty_reduce_error()
reduce_empty(::typeof(add_sum), ::Type{T}) where {T} = reduce_empty(+, T)
reduce_empty(::typeof(add_sum), ::Type{T}) where {T<:SmallSigned} = zero(Int)
Expand Down Expand Up @@ -346,8 +349,10 @@ mapreduce_empty(::typeof(identity), op, T) = reduce_empty(op, T)
mapreduce_empty(::typeof(abs), op, T) = abs(reduce_empty(op, T))
mapreduce_empty(::typeof(abs2), op, T) = abs2(reduce_empty(op, T))

mapreduce_empty(f::typeof(abs), ::typeof(max), T) = abs(zero(T))
mapreduce_empty(f::typeof(abs2), ::typeof(max), T) = abs2(zero(T))
mapreduce_empty(::typeof(abs), ::typeof(max), T) = abs(zero(T))
mapreduce_empty(::typeof(abs), ::typeof(min), T::Type{<:AbstractFloat}) = typemax(T)
mapreduce_empty(::typeof(abs2), ::typeof(max), T) = abs2(zero(T))
mapreduce_empty(::typeof(abs2), ::typeof(min), T::Type{<:AbstractFloat}) = typemax(T)

# For backward compatibility:
mapreduce_empty_iter(f, op, itr, ItrEltype) =
Expand Down
17 changes: 17 additions & 0 deletions test/reduce.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -87,6 +87,8 @@ end
@test mapreduce(abs2, *, Float64[]) === 1.0
@test mapreduce(abs2, max, Float64[]) === 0.0
@test mapreduce(abs, max, Float64[]) === 0.0
@test mapreduce(abs2, min, Float64[]) === Inf
@test mapreduce(abs, min, Float64[]) === Inf
@test_throws ArgumentError mapreduce(abs2, &, Float64[])
@test_throws ArgumentError mapreduce(abs2, |, Float64[])

Expand Down Expand Up @@ -245,6 +247,21 @@ prod2(itr) = invoke(prod, Tuple{Any}, itr)
@test maximum(Int[]; init=-1) == -1
@test minimum(Int[]; init=-1) == -1

@test maximum(Float64[]) === -Inf
@test minimum(Float64[]) === +Inf

@test maximum(Float32[]) === -Inf32
@test minimum(Float32[]) === +Inf32

@test maximum(abs, Int[]) === 0
@test_throws ArgumentError minimum(abs, Int[])

@test maximum(abs, Float64[]) === 0.0
@test minimum(abs, Float64[]) === +Inf

@test maximum(abs, Float32[]) === 0.0f0
@test minimum(abs, Float32[]) === +Inf32

@test maximum(5) == 5
@test minimum(5) == 5
@test extrema(5) == (5, 5)
Expand Down