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replace the API of replace (#25697)
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Make nothing not special.
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@rfourquet @nalimilan
rfourquet authored and nalimilan committed Feb 1, 2018
1 parent ecb8b56 commit dce9d05
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98 changes: 33 additions & 65 deletions base/set.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -565,7 +565,7 @@ convert(::Type{T}, s::AbstractSet) where {T<:AbstractSet} = T(s)
## replace/replace! ##

# to make replace/replace! work for a new container type Cont, only
# replace!(prednew::Callable, A::Cont; count::Integer=typemax(Int))
# replace!(new::Callable, A::Cont; count::Integer=typemax(Int))
# has to be implemented

"""
Expand All @@ -591,15 +591,14 @@ Set([0, 2, 3])
"""
replace!(A, old_new::Pair...; count::Integer=typemax(Int)) = _replace!(A, eltype(A), count, old_new)

# we use this wrapper because using directly eltype(A) as the type
# parameter below for Some degrades performance
function _replace!(A, ::Type{K}, count::Integer, old_new::Tuple{Vararg{Pair}}) where K
@inline function prednew(x)
@inline function new(x)
for o_n in old_new
first(o_n) == x && return Some{K}(last(o_n))
first(o_n) == x && return last(o_n)
end
return x # no replace
end
replace!(prednew, A, count=count)
replace!(new, A, count=count)
end

"""
Expand All @@ -621,37 +620,26 @@ julia> replace!(isodd, A, 0, count=2)
```
"""
replace!(pred::Callable, A, new; count::Integer=typemax(Int)) =
replace!(x -> if pred(x) Some(new) end, A, count=count)
replace!(x -> ifelse(pred(x), new, x), A, count=count)

"""
replace!(prednew::Function, A; [count::Integer])
replace!(new::Function, A; [count::Integer])
For each value `x` in `A`, `prednew(x)` is called and must
return either `nothing`, in which case no replacement occurs,
or a value, possibly wrapped as a [`Some`](@ref) object, which
will be used as a replacement for `x`.
Replace each element `x` in collection `A` by `new(x)`.
If `count` is specified, then replace at most `count` values in total
(replacements being defined as `new(x) !== x`).
# Examples
```jldoctest
julia> replace!(x -> isodd(x) ? 2x : nothing, [1, 2, 3, 4])
julia> replace!(x -> isodd(x) ? 2x : x, [1, 2, 3, 4])
4-element Array{Int64,1}:
2
2
6
4
julia> replace!(Union{Int,Nothing}[0, 1, 2, nothing, 4], count=2) do x
x !== nothing && iseven(x) ? Some(nothing) : nothing
end
5-element Array{Union{Nothing,Int64},1}:
nothing
1
nothing
nothing
4
julia> replace!(Dict(1=>2, 3=>4)) do kv
if first(kv) < 3; first(kv)=>3 end
first(kv) < 3 ? first(kv)=>3 : kv
end
Dict{Int64,Int64} with 2 entries:
3 => 4
Expand All @@ -661,10 +649,10 @@ julia> replace!(x->2x, Set([3, 6]))
Set([6, 12])
```
"""
function replace!(prednew::Callable, A::Union{AbstractArray,AbstractDict,AbstractSet};
function replace!(new::Callable, A::Union{AbstractArray,AbstractDict,AbstractSet};
count::Integer=typemax(Int))
count < 0 && throw(DomainError(count, "`count` must not be negative"))
count != 0 && _replace!(prednew, A, min(count, typemax(Int)) % Int)
count != 0 && _replace!(new, A, min(count, typemax(Int)) % Int)
A
end

Expand Down Expand Up @@ -706,44 +694,31 @@ julia> replace(isodd, [1, 2, 3, 1], 0, count=2)
```
"""
replace(pred::Callable, A, new; count::Integer=typemax(Int)) =
replace!(x -> if pred(x) Some(new) end, copy(A), count=count)
replace!(pred, copy(A), new, count=count)

"""
replace(prednew::Function, A; [count::Integer])
replace(new::Function, A; [count::Integer])
Return a copy of `A` where for each value `x` in `A`, `prednew(x)` is called
and must return either `nothing`, in which case no replacement occurs,
or a value, possibly wrapped as a [`Some`](@ref) object, which
will be used as a replacement for `x`.
Return a copy of `A` where each value `x` in `A` is replaced by `new(x)`
# Examples
```jldoctest
julia> replace(x -> isodd(x) ? 2x : nothing, [1, 2, 3, 4])
julia> replace(x -> isodd(x) ? 2x : x, [1, 2, 3, 4])
4-element Array{Int64,1}:
2
2
6
4
julia> replace(Union{Int,Nothing}[0, 1, 2, nothing, 4], count=2) do x
x !== nothing && iseven(x) ? Some(nothing) : nothing
end
5-element Array{Union{Nothing,Int64},1}:
nothing
1
nothing
nothing
4
julia> replace(Dict(1=>2, 3=>4)) do kv
if first(kv) < 3; first(kv)=>3 end
first(kv) < 3 ? first(kv)=>3 : kv
end
Dict{Int64,Int64} with 2 entries:
3 => 4
1 => 3
```
"""
replace(prednew::Callable, A; count::Integer=typemax(Int)) = replace!(prednew, copy(A), count=count)
replace(new::Callable, A; count::Integer=typemax(Int)) = replace!(new, copy(A), count=count)

# Handle ambiguities
replace!(a::Callable, b::Pair; count::Integer=-1) = throw(MethodError(replace!, (a, b)))
Expand All @@ -758,19 +733,15 @@ replace(a::AbstractString, b::Pair, c::Pair) = throw(MethodError(replace, (a, b,
askey(k, ::AbstractDict) = k.first
askey(k, ::AbstractSet) = k

function _replace_update_dict!(repl::Vector{<:Pair}, x, y::Some)
push!(repl, x => y.value)
true
end

_replace_update_dict!(repl::Vector{<:Pair}, x, ::Nothing) = false
_replace_update_dict!(repl::Vector{<:Pair}, x, y) = _replace_update_dict!(repl, x, Some(y))

function _replace!(prednew::Callable, A::Union{AbstractDict,AbstractSet}, count::Int)
function _replace!(new::Callable, A::Union{AbstractDict,AbstractSet}, count::Int)
repl = Pair{eltype(A),eltype(A)}[]
c = 0
for x in A
c += _replace_update_dict!(repl, x, prednew(x))
y = new(x)
if x !== y
push!(repl, x => y)
c += 1
end
c == count && break
end
for oldnew in repl
Expand All @@ -783,18 +754,15 @@ end

### AbstractArray

function _replace_update!(A::AbstractArray, i::Integer, y::Some)
@inbounds A[i] = y.value
true
end

_replace_update!(A::AbstractArray, i::Integer, ::Nothing) = false
_replace_update!(A::AbstractArray, i::Integer, y) = _replace_update!(A, i, Some(y))

function _replace!(prednew::Callable, A::AbstractArray, count::Int)
function _replace!(new::Callable, A::AbstractArray, count::Int)
c = 0
for i in eachindex(A)
c += _replace_update!(A, i, prednew(A[i]))
@inbounds Ai = A[i]
y = new(Ai)
if Ai !== y
@inbounds A[i] = y
c += 1
end
c == count && break
end
end
89 changes: 38 additions & 51 deletions test/sets.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -492,65 +492,52 @@ end
end

@testset "replace! & replace" begin
maybe1(v, p) = if p Some(v) end
maybe2(v, p) = if p v end

for maybe = (maybe1, maybe2)
a = [1, 2, 3, 1]
@test replace(x->maybe(2x, iseven(x)), a) == [1, 4, 3, 1]
@test replace!(x->maybe(2x, iseven(x)), a) === a
@test a == [1, 4, 3, 1]
@test replace(a, 1=>0) == [0, 4, 3, 0]
for count = (1, 0x1, big(1))
@test replace(a, 1=>0, count=count) == [0, 4, 3, 1]
end
@test replace!(a, 1=>2) === a
@test a == [2, 4, 3, 2]
@test replace!(x->2x, a, count=0x2) == [4, 8, 3, 2]

d = Dict(1=>2, 3=>4)
@test replace(x->x.first > 2, d, 0=>0) == Dict(1=>2, 0=>0)
@test replace!(x->maybe(x.first=>2*x.second, x.first > 2), d) === d
@test d == Dict(1=>2, 3=>8)
@test replace(d, (3=>8)=>(0=>0)) == Dict(1=>2, 0=>0)
@test replace!(d, (3=>8)=>(2=>2)) === d
@test d == Dict(1=>2, 2=>2)
for count = (1, 0x1, big(1))
@test replace(x->x.second == 2, d, 0=>0, count=count) in [Dict(1=>2, 0=>0),
Dict(2=>2, 0=>0)]
end
s = Set([1, 2, 3])
@test replace(x->maybe(2x, x>1), s) == Set([1, 4, 6])
for count = (1, 0x1, big(1))
@test replace(x->maybe(2x, x>1), s, count=count) in [Set([1, 4, 3]), Set([1, 2, 6])]
end
@test replace(s, 1=>4) == Set([2, 3, 4])
@test replace!(s, 1=>2) === s
@test s == Set([2, 3])
@test replace!(x->2x, s, count=0x1) in [Set([4, 3]), Set([2, 6])]
a = [1, 2, 3, 1]
@test replace(x -> iseven(x) ? 2x : x, a) == [1, 4, 3, 1]
@test replace!(x -> iseven(x) ? 2x : x, a) === a
@test a == [1, 4, 3, 1]
@test replace(a, 1=>0) == [0, 4, 3, 0]
for count = (1, 0x1, big(1))
@test replace(a, 1=>0, count=count) == [0, 4, 3, 1]
end
@test replace!(a, 1=>2) === a
@test a == [2, 4, 3, 2]
@test replace!(x->2x, a, count=0x2) == [4, 8, 3, 2]

d = Dict(1=>2, 3=>4)
@test replace(x->x.first > 2, d, 0=>0) == Dict(1=>2, 0=>0)
@test replace!(x -> x.first > 2 ? x.first=>2*x.second : x, d) === d
@test d == Dict(1=>2, 3=>8)
@test replace(d, (3=>8)=>(0=>0)) == Dict(1=>2, 0=>0)
@test replace!(d, (3=>8)=>(2=>2)) === d
@test d == Dict(1=>2, 2=>2)
for count = (1, 0x1, big(1))
@test replace(x->x.second == 2, d, 0=>0, count=count) in [Dict(1=>2, 0=>0),
Dict(2=>2, 0=>0)]
end
s = Set([1, 2, 3])
@test replace(x -> x > 1 ? 2x : x, s) == Set([1, 4, 6])
for count = (1, 0x1, big(1))
@test replace(x -> x > 1 ? 2x : x, s, count=count) in [Set([1, 4, 3]), Set([1, 2, 6])]
end
@test replace(s, 1=>4) == Set([2, 3, 4])
@test replace!(s, 1=>2) === s
@test s == Set([2, 3])
@test replace!(x->2x, s, count=0x1) in [Set([4, 3]), Set([2, 6])]

for count = (0, 0x0, big(0))
@test replace([1, 2], 1=>0, 2=>0, count=count) == [1, 2] # count=0 --> no replacements
end
for count = (0, 0x0, big(0))
@test replace([1, 2], 1=>0, 2=>0, count=count) == [1, 2] # count=0 --> no replacements
end

# test collisions with AbstractSet/AbstractDict
@test replace!(x->2x, Set([3, 6])) == Set([6, 12])
@test replace!(x->2x, Set([1:20;])) == Set([2:2:40;])
@test replace!(kv -> (2kv[1] => kv[2]), Dict(1=>2, 2=>4, 4=>8, 8=>16)) == Dict(2=>2, 4=>4, 8=>8, 16=>16)

# test Some(nothing)
# test nothing & Some(nothing) (should behave as any other value)
a = [1, 2, nothing, 4]
@test replace(x -> x === nothing ? 0 : Some(nothing), a) == [nothing, nothing, 0, nothing]
@test replace(x -> x === nothing ? 0 : nothing, a) == [1, 2, 0, 4]
@test replace!(x -> x !== nothing ? Some(nothing) : nothing, a) == [nothing, nothing, nothing, nothing]
@test replace(iseven, Any[1, 2, 3, 4], nothing) == [1, nothing, 3, nothing]
@test replace(Any[1, 2, 3, 4], 1=>nothing, 3=>nothing) == [nothing, 2, nothing, 4]
s = Set([1, 2, nothing, 4])
@test replace(x -> x === nothing ? 0 : Some(nothing), s) == Set([0, nothing])
@test replace(x -> x === nothing ? 0 : nothing, s) == Set([1, 2, 0, 4])
@test replace(x -> x !== nothing ? Some(nothing) : nothing, s) == Set([nothing])
@test replace(iseven, Set(Any[1, 2, 3, 4]), nothing) == Set([1, nothing, 3, nothing])
@test replace(Set(Any[1, 2, 3, 4]), 1=>nothing, 3=>nothing) == Set([nothing, 2, nothing, 4])
@test replace(x -> x === nothing ? Some(nothing) : nothing, a) == [nothing, nothing, Some(nothing), nothing]
@test replace(x -> x === nothing ? Some(nothing) : nothing, Set(a)) == Set([Some(nothing), nothing])

# avoid recursive call issue #25384
@test_throws MethodError replace!("")
Expand Down

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