Non-mutating versions of pop, popfirst, etc. (#66)

src/ArrayInterface.jl

@@ -4,7 +4,7 @@ using Requires
 using LinearAlgebra
 using SparseArrays
 
-using Base: OneTo
+using Base: OneTo, @propagate_inbounds
 
 Base.@pure __parameterless_type(T) = Base.typename(T).wrapper
 parameterless_type(x) = parameterless_type(typeof(x))
@@ -543,6 +543,103 @@ function restructure(x::Array,y)
   reshape(convert(Array,y),size(x)...)
 end
 
+"""
+    insert(collection, index, item)
+
+Return a new instance of `collection` with `item` inserted into at the given `index`.
+"""
+Base.@propagate_inbounds function insert(collection, index, item)
+  @boundscheck checkbounds(collection, index)
+  ret = similar(collection, length(collection) + 1)
+  @inbounds for i in firstindex(ret):(index - 1)
+      ret[i] = collection[i]
+  end
+  @inbounds ret[index] = item
+  @inbounds for i in (index + 1):lastindex(ret)
+      ret[i] = collection[i - 1]
+  end
+  return ret
+end
+
+function insert(x::Tuple, index::Integer, item)
+  @boundscheck if !checkindex(Bool, static_first(x):static_last(x), index)
+    throw(BoundsError(x, index))
+  end
+  return unsafe_insert(x, Int(index), item)
+end
+
+@inline function unsafe_insert(x::Tuple, i::Int, item)
+  if i === 1
+    return (item, x...)
+  else
+    return (first(x), unsafe_insert(Base.tail(x), i - 1, item)...)
+  end
+end
+
+"""
+    deleteat(collection, index)
+
+Return a new instance of `collection` with the item at the given `index` removed.
+"""
+@propagate_inbounds function deleteat(collection::AbstractVector, index)
+  @boundscheck if !checkindex(Bool, eachindex(collection), index)
+    throw(BoundsError(collection, index))
+  end
+  return unsafe_deleteat(collection, index)
+end
+@propagate_inbounds function deleteat(collection::Tuple, index)
+  @boundscheck if !checkindex(Bool, static_first(collection):static_last(collection), index)
+    throw(BoundsError(collection, index))
+  end
+  return unsafe_deleteat(collection, index)
+end
+
+function unsafe_deleteat(src::AbstractVector, index::Integer)
+  dst = similar(src, length(src) - 1)
+  @inbounds for i in indices(dst)
+    if i < index
+      dst[i] = src[i]
+    else
+      dst[i] = src[i + 1]
+    end
+  end
+  return dst
+end
+
+@inline function unsafe_deleteat(src::AbstractVector, inds::AbstractVector)
+  dst = similar(src, length(src) - length(inds))
+  dst_index = firstindex(dst)
+  @inbounds for src_index in indices(src)
+    if !in(src_index, inds)
+      dst[dst_index] = src[src_index]
+      dst_index += one(dst_index)
+    end
+  end
+  return dst
+end
+
+@inline function unsafe_deleteat(src::Tuple, inds::AbstractVector)
+  dst = Vector{eltype(src)}(undef, length(src) - length(inds))
+  dst_index = firstindex(dst)
+  @inbounds for src_index in OneTo(length(src))
+    if !in(src_index, inds)
+      dst[dst_index] = src[src_index]
+      dst_index += one(dst_index)
+    end
+  end
+  return Tuple(dst)
+end
+
+@inline function unsafe_deleteat(x::Tuple, i::Integer)
+  if i === one(i)
+    return Base.tail(x)
+  elseif i == length(x)
+    return Base.front(x)
+  else
+    return (first(x), unsafe_deleteat(Base.tail(x), i - one(i))...)
+  end
+end
+
 function __init__()
 
   @require SuiteSparse="4607b0f0-06f3-5cda-b6b1-a6196a1729e9" begin

src/ranges.jl

@@ -42,12 +42,6 @@ known_step(::Type{<:AbstractUnitRange{T}}) where {T} = one(T)
 
 # add methods to support ArrayInterface
 
-_get(x) = x
-_get(::Static{V}) where {V} = V
-_get(::Type{Static{V}}) where {V} = V
-_convert(::Type{T}, x) where {T} = convert(T, x)
-_convert(::Type{T}, ::Val{V}) where {T,V} = Val(convert(T, V))
-
 """
     OptionallyStaticUnitRange{T<:Integer}(start, stop) <: OrdinalRange{T,T}
 
@@ -57,28 +51,23 @@ at compile time. An `OptionallyStaticUnitRange` is intended to be constructed in
 from other valid indices. Therefore, users should not expect the same checks are used
 to ensure construction of a valid `OptionallyStaticUnitRange` as a `UnitRange`.
 """
-struct OptionallyStaticUnitRange{T <: Integer, F <: Integer, L <: Integer} <: AbstractUnitRange{T}
+struct OptionallyStaticUnitRange{F <: Integer, L <: Integer} <: AbstractUnitRange{Int}
   start::F
   stop::L
 
-  function OptionallyStaticUnitRange{T}(start, stop) where {T<:Real}
-    if _get(start) isa T
-      if _get(stop) isa T
-        return new{T,typeof(start),typeof(stop)}(start, stop)
+  function OptionallyStaticUnitRange(start, stop)
+    if eltype(start) <: Int
+      if eltype(stop) <: Int
+        return new{typeof(start),typeof(stop)}(start, stop)
       else
-        return OptionallyStaticUnitRange{T}(start, _convert(T, stop))
+        return OptionallyStaticUnitRange(start, Int(stop))
       end
     else
-      return OptionallyStaticUnitRange{T}(_convert(T, start), stop)
+      return OptionallyStaticUnitRange(Int(start), stop)
     end
   end
 
-  function OptionallyStaticUnitRange(start, stop)
-    T = promote_type(typeof(_get(start)), typeof(_get(stop)))
-    return OptionallyStaticUnitRange{T}(start, stop)
-  end
-
-  function OptionallyStaticUnitRange(x::AbstractRange)
+ function OptionallyStaticUnitRange(x::AbstractRange)
     if step(x) == 1
       fst = static_first(x)
       lst = static_last(x)
@@ -94,12 +83,12 @@ Base.:(:)(::Static{L}, U::Integer) where {L} = OptionallyStaticUnitRange(Static(
 Base.:(:)(::Static{L}, ::Static{U}) where {L,U} = OptionallyStaticUnitRange(Static(L), Static(U))
 
 Base.first(r::OptionallyStaticUnitRange) = r.start
-Base.step(r::OptionallyStaticUnitRange{T}) where {T} = oneunit(T)
+Base.step(::OptionallyStaticUnitRange) = Static(1)
 Base.last(r::OptionallyStaticUnitRange) = r.stop
 
-known_first(::Type{<:OptionallyStaticUnitRange{<:Any,Static{F}}}) where {F} = F
-known_step(::Type{<:OptionallyStaticUnitRange{T}}) where {T} = one(T)
-known_last(::Type{<:OptionallyStaticUnitRange{<:Any,<:Any,Static{L}}}) where {L} = L
+known_first(::Type{<:OptionallyStaticUnitRange{Static{F}}}) where {F} = F
+known_step(::Type{<:OptionallyStaticUnitRange}) = 1
+known_last(::Type{<:OptionallyStaticUnitRange{<:Any,Static{L}}}) where {L} = L
 
 function Base.isempty(r::OptionallyStaticUnitRange)
   if known_first(r) === oneunit(eltype(r))
@@ -112,10 +101,8 @@ end
 unsafe_isempty_one_to(lst) = lst <= zero(lst)
 unsafe_isempty_unit_range(fst, lst) = fst > lst
 
-unsafe_isempty_unit_range(fst::T, lst::T) where {T} = Integer(lst - fst + one(T))
-
-unsafe_length_one_to(lst::T) where {T<:Int} = T(lst)
-unsafe_length_one_to(lst::T) where {T} = Integer(lst - zero(lst))
+unsafe_length_one_to(lst::Int) = lst
+unsafe_length_one_to(::Static{L}) where {L} = lst
 
 Base.@propagate_inbounds function Base.getindex(r::OptionallyStaticUnitRange, i::Integer)
   if known_first(r) === oneunit(r)
@@ -144,15 +131,15 @@ end
 @inline _try_static(::Static{M}, ::Static{N}) where {M, N} = @assert false "Unequal Indices: Static{$M}() != Static{$N}()"
 function _try_static(::Static{N}, x) where {N}
     @assert N == x "Unequal Indices: Static{$N}() != x == $x"
-    Static{N}()
+    return Static{N}()
 end
 function _try_static(x, ::Static{N}) where {N}
     @assert N == x "Unequal Indices: x == $x != Static{$N}()"
-    Static{N}()
+    return Static{N}()
 end
 function _try_static(x, y)
     @assert x == y "Unequal Indicess: x == $x != $y == y"
-    x
+    return x
 end
 
 ###
@@ -172,24 +159,19 @@ end
   end
 end
 
-function Base.length(r::OptionallyStaticUnitRange{T}) where {T}
+function Base.length(r::OptionallyStaticUnitRange)
   if isempty(r)
-    return zero(T)
+    return 0
   else
-    if known_one(r) === one(T)
+    if known_first(r) === 0
       return unsafe_length_one_to(last(r))
     else
       return unsafe_length_unit_range(first(r), last(r))
     end
   end
 end
 
-function unsafe_length_unit_range(fst::T, lst::T) where {T<:Union{Int,Int64,Int128}}
-  return Base.checked_add(Base.checked_sub(lst, fst), one(T))
-end
-function unsafe_length_unit_range(fst::T, lst::T) where {T<:Union{UInt,UInt64,UInt128}}
-  return Base.checked_add(lst - fst, one(T))
-end
+unsafe_length_unit_range(start::Integer, stop::Integer) = Int(start - stop + 1)
 
 """
     indices(x[, d])
@@ -231,4 +213,3 @@ end
   lst = _try_static(static_last(x), static_last(y))
   return Base.Slice(OptionallyStaticUnitRange(fst, lst))
 end
-

src/static.jl

@@ -6,6 +6,10 @@ Use `Static(N)` instead of `Val(N)` when you want it to behave like a number.
 struct Static{N} <: Integer
     Static{N}() where {N} = new{N::Int}()
 end
+
+const Zero = Static{0}
+const One = Static{1}
+
 Base.@pure Static(N::Int) = Static{N}()
 Static(N::Integer) = Static(convert(Int, N))
 Static(::Static{N}) where {N} = Static{N}()
@@ -33,41 +37,44 @@ end
 Base.promote_rule(::Type{<:Static}, ::Type{<:Static}) = Int
 Base.:(%)(::Static{N}, ::Type{Integer}) where {N} = N
 
-Base.iszero(::Static{0}) = true
+Base.eltype(::Type{T}) where {T<:Static} = Int
+Base.iszero(::Zero) = true
 Base.iszero(::Static) = false
-Base.isone(::Static{1}) = true
+Base.isone(::One) = true
 Base.isone(::Static) = false
+Base.zero(::Type{T}) where {T<:Static} = Zero()
+Base.one(::Type{T}) where {T<:Static} = One()
 
 for T = [:Real, :Rational, :Integer]
     @eval begin
-        @inline Base.:(+)(i::$T, ::Static{0}) = i
+        @inline Base.:(+)(i::$T, ::Zero) = i
         @inline Base.:(+)(i::$T, ::Static{M}) where {M} = i + M
-        @inline Base.:(+)(::Static{0}, i::$T) = i
+        @inline Base.:(+)(::Zero, i::$T) = i
         @inline Base.:(+)(::Static{M}, i::$T) where {M} = M + i
-        @inline Base.:(-)(i::$T, ::Static{0}) = i
+        @inline Base.:(-)(i::$T, ::Zero) = i
         @inline Base.:(-)(i::$T, ::Static{M}) where {M} = i - M
-        @inline Base.:(*)(i::$T, ::Static{0}) = Static{0}()
-        @inline Base.:(*)(i::$T, ::Static{1}) = i
+        @inline Base.:(*)(i::$T, ::Zero) = Zero()
+        @inline Base.:(*)(i::$T, ::One) = i
         @inline Base.:(*)(i::$T, ::Static{M}) where {M} = i * M
-        @inline Base.:(*)(::Static{0}, i::$T) = Static{0}()
-        @inline Base.:(*)(::Static{1}, i::$T) = i
+        @inline Base.:(*)(::Zero, i::$T) = Zero()
+        @inline Base.:(*)(::One, i::$T) = i
         @inline Base.:(*)(::Static{M}, i::$T) where {M} = M * i
     end
 end
-@inline Base.:(+)(::Static{0}, ::Static{0}) = Static{0}()
-@inline Base.:(+)(::Static{0}, ::Static{M}) where {M} = Static{M}()
-@inline Base.:(+)(::Static{M}, ::Static{0}) where {M} = Static{M}()
+@inline Base.:(+)(::Zero, ::Zero) = Zero()
+@inline Base.:(+)(::Zero, ::Static{M}) where {M} = Static{M}()
+@inline Base.:(+)(::Static{M}, ::Zero) where {M} = Static{M}()
 
-@inline Base.:(-)(::Static{M}, ::Static{0}) where {M} = Static{M}()
+@inline Base.:(-)(::Static{M}, ::Zero) where {M} = Static{M}()
 
-@inline Base.:(*)(::Static{0}, ::Static{0}) = Static{0}()
-@inline Base.:(*)(::Static{1}, ::Static{0}) = Static{0}()
-@inline Base.:(*)(::Static{0}, ::Static{1}) = Static{0}()
-@inline Base.:(*)(::Static{1}, ::Static{1}) = Static{1}()
-@inline Base.:(*)(::Static{M}, ::Static{0}) where {M} = Static{0}()
-@inline Base.:(*)(::Static{0}, ::Static{M}) where {M} = Static{0}()
-@inline Base.:(*)(::Static{M}, ::Static{1}) where {M} = Static{M}()
-@inline Base.:(*)(::Static{1}, ::Static{M}) where {M} = Static{M}()
+@inline Base.:(*)(::Zero, ::Zero) = Zero()
+@inline Base.:(*)(::One, ::Zero) = Zero()
+@inline Base.:(*)(::Zero, ::One) = Zero()
+@inline Base.:(*)(::One, ::One) = One()
+@inline Base.:(*)(::Static{M}, ::Zero) where {M} = Zero()
+@inline Base.:(*)(::Zero, ::Static{M}) where {M} = Zero()
+@inline Base.:(*)(::Static{M}, ::One) where {M} = Static{M}()
+@inline Base.:(*)(::One, ::Static{M}) where {M} = Static{M}()
 for f ∈ [:(+), :(-), :(*), :(/), :(÷), :(%), :(<<), :(>>), :(>>>), :(&), :(|), :(⊻)]
     @eval @generated Base.$f(::Static{M}, ::Static{N}) where {M,N} = Expr(:call, Expr(:curly, :Static, $f(M, N)))
 end

test/runtests.jl

@@ -252,6 +252,9 @@ end
 @testset "Static" begin
     @test iszero(Static(0))
     @test !iszero(Static(1))
+    @test @inferred(one(Static)) === Static(1)
+    @test @inferred(zero(Static)) === Static(0)
+    @test eltype(one(Static)) <: Int
     # test for ambiguities and correctness
     for i ∈ [Static(0), Static(1), Static(2), 3]
         for j ∈ [Static(0), Static(1), Static(2), 3]
@@ -271,3 +274,22 @@ end
     end
 end
 
+@testset "insert/deleteat" begin
+    @test @inferred(ArrayInterface.insert([1,2,3], 2, -2)) == [1, -2, 2, 3]
+    @test @inferred(ArrayInterface.deleteat([1, 2, 3], 2)) == [1, 3]
+
+    @test @inferred(ArrayInterface.deleteat([1, 2, 3], [1, 2])) == [3]
+    @test @inferred(ArrayInterface.deleteat([1, 2, 3], [1, 3])) == [2]
+    @test @inferred(ArrayInterface.deleteat([1, 2, 3], [2, 3])) == [1]
+
+
+    @test @inferred(ArrayInterface.insert((1,2,3), 1, -2)) == (-2, 1, 2, 3)
+    @test @inferred(ArrayInterface.insert((1,2,3), 2, -2)) == (1, -2, 2, 3)
+    @test @inferred(ArrayInterface.insert((1,2,3), 3, -2)) == (1, 2, -2, 3)
+
+    @test @inferred(ArrayInterface.deleteat((1, 2, 3), 1)) == (2, 3)
+    @test @inferred(ArrayInterface.deleteat((1, 2, 3), 2)) == (1, 3)
+    @test @inferred(ArrayInterface.deleteat((1, 2, 3), 3)) == (1, 2)
+    @test ArrayInterface.deleteat((1, 2, 3), [1, 2]) == (3,)
+end
+