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range.jl
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# This file is a part of Julia. License is MIT: https://julialang.org/license
(:)(a::Real, b::Real) = (:)(promote(a,b)...)
(:)(start::T, stop::T) where {T<:Real} = UnitRange{T}(start, stop)
(:)(start::T, stop::T) where {T} = (:)(start, oftype(stop-start, 1), stop)
# promote start and stop, leaving step alone
(:)(start::A, step, stop::C) where {A<:Real,C<:Real} =
(:)(convert(promote_type(A,C),start), step, convert(promote_type(A,C),stop))
# AbstractFloat specializations
(:)(a::T, b::T) where {T<:AbstractFloat} = (:)(a, T(1), b)
(:)(a::T, b::AbstractFloat, c::T) where {T<:Real} = (:)(promote(a,b,c)...)
(:)(a::T, b::AbstractFloat, c::T) where {T<:AbstractFloat} = (:)(promote(a,b,c)...)
(:)(a::T, b::Real, c::T) where {T<:AbstractFloat} = (:)(promote(a,b,c)...)
(:)(start::T, step::T, stop::T) where {T<:AbstractFloat} =
_colon(OrderStyle(T), ArithmeticStyle(T), start, step, stop)
(:)(start::T, step::T, stop::T) where {T<:Real} =
_colon(OrderStyle(T), ArithmeticStyle(T), start, step, stop)
_colon(::Ordered, ::Any, start::T, step, stop::T) where {T} = StepRange(start, step, stop)
# for T<:Union{Float16,Float32,Float64} see twiceprecision.jl
_colon(::Ordered, ::ArithmeticRounds, start::T, step, stop::T) where {T} =
StepRangeLen(start, step, floor(Int, (stop-start)/step)+1)
_colon(::Any, ::Any, start::T, step, stop::T) where {T} =
StepRangeLen(start, step, floor(Int, (stop-start)/step)+1)
"""
(:)(start, [step], stop)
Range operator. `a:b` constructs a range from `a` to `b` with a step size of 1 (a [`UnitRange`](@ref))
, and `a:s:b` is similar but uses a step size of `s` (a [`StepRange`](@ref)).
`:` is also used in indexing to select whole dimensions
and for [`Symbol`](@ref) literals, as in e.g. `:hello`.
"""
(:)(start::T, step, stop::T) where {T} = _colon(start, step, stop)
(:)(start::T, step, stop::T) where {T<:Real} = _colon(start, step, stop)
# without the second method above, the first method above is ambiguous with
# (:)(start::A, step, stop::C) where {A<:Real,C<:Real}
function _colon(start::T, step, stop::T) where T
T′ = typeof(start+zero(step))
StepRange(convert(T′,start), step, convert(T′,stop))
end
"""
range(start, stop; length, step)
range(start; length, stop, step)
range(;start, length, stop, step)
Construct a specialized array with evenly spaced elements and optimized storage (an [`AbstractRange`](@ref)) from the arguments.
Mathematically a range is uniquely determined by any three of `start`, `step`, `stop` and `length`.
Valid invocations of range are:
* Call `range` with any three of `start`, `step`, `stop`, `length`.
* Call `range` with two of `start`, `stop`, `length`. In this case `step` will be assumed
to be one. If both arguments are Integers, a [`UnitRange`](@ref) will be returned.
# Examples
```jldoctest
julia> range(1, length=100)
1:100
julia> range(1, stop=100)
1:100
julia> range(1, step=5, length=100)
1:5:496
julia> range(1, step=5, stop=100)
1:5:96
julia> range(1, 10, length=101)
1.0:0.09:10.0
julia> range(1, 100, step=5)
1:5:96
julia> range(stop=10, length=5)
6:10
julia> range(stop=10, step=1, length=5)
6:1:10
julia> range(start=1, step=1, stop=10)
1:1:10
```
If `length` is not specified and `stop - start` is not an integer multiple of `step`, a range that ends before `stop` will be produced.
```jldoctest
julia> range(1, 3.5, step=2)
1.0:2.0:3.0
```
Special care is taken to ensure intermediate values are computed rationally.
To avoid this induced overhead, see the [`LinRange`](@ref) constructor.
Both `start` and `stop` may be specified as either a positional or keyword arguments.
If both are specified as positional arguments, one of `step` or `length` must also be provided.
!!! compat "Julia 1.1"
`stop` as a positional argument requires at least Julia 1.1.
!!! compat "Julia 1.7"
`start` as a keyword argument requires at least Julia 1.7.
"""
function range end
range(start; stop=nothing, length::Union{Integer,Nothing}=nothing, step=nothing) =
_range(start, step, stop, length)
function range(start, stop; length::Union{Integer,Nothing}=nothing, step=nothing)
# For code clarity, the user must pass step or length
# See https://github.com/JuliaLang/julia/pull/28708#issuecomment-420034562
if step === length === nothing
msg = """
Neither `step` nor `length` was provided. To fix this do one of the following:
* Pass one of them
* Use `$(start):$(stop)`
* Use `range($start, stop=$stop)`
"""
throw(ArgumentError(msg))
end
_range(start, step, stop, length)
end
range(;start=nothing, stop=nothing, length::Union{Integer, Nothing}=nothing, step=nothing) =
_range(start, step, stop, length)
_range(start::Nothing, step::Nothing, stop::Nothing, len::Nothing) = range_error(start, step, stop, len)
_range(start::Nothing, step::Nothing, stop::Nothing, len::Any ) = range_error(start, step, stop, len)
_range(start::Nothing, step::Nothing, stop::Any , len::Nothing) = range_error(start, step, stop, len)
_range(start::Nothing, step::Nothing, stop::Any , len::Any ) = range_stop_length(stop, len)
_range(start::Nothing, step::Any , stop::Nothing, len::Nothing) = range_error(start, step, stop, len)
_range(start::Nothing, step::Any , stop::Nothing, len::Any ) = range_error(start, step, stop, len)
_range(start::Nothing, step::Any , stop::Any , len::Nothing) = range_error(start, step, stop, len)
_range(start::Nothing, step::Any , stop::Any , len::Any ) = range_step_stop_length(step, stop, len)
_range(start::Any , step::Nothing, stop::Nothing, len::Nothing) = range_error(start, step, stop, len)
_range(start::Any , step::Nothing, stop::Nothing, len::Any ) = range_start_length(start, len)
_range(start::Any , step::Nothing, stop::Any , len::Nothing) = range_start_stop(start, stop)
_range(start::Any , step::Nothing, stop::Any , len::Any ) = range_start_stop_length(start, stop, len)
_range(start::Any , step::Any , stop::Nothing, len::Nothing) = range_error(start, step, stop, len)
_range(start::Any , step::Any , stop::Nothing, len::Any ) = range_start_step_length(start, step, len)
_range(start::Any , step::Any , stop::Any , len::Nothing) = range_start_step_stop(start, step, stop)
_range(start::Any , step::Any , stop::Any , len::Any ) = range_error(start, step, stop, len)
range_stop_length(stop, length) = (stop-length+1):stop
range_step_stop_length(step, stop, length) = reverse(range_start_step_length(stop, -step, length))
range_start_length(a::Real, len::Integer) = UnitRange{typeof(a)}(a, oftype(a, a+len-1))
range_start_length(a::AbstractFloat, len::Integer) = range_start_step_length(a, oftype(a, 1), len)
range_start_length(a, len::Integer) = range_start_step_length(a, oftype(a-a, 1), len)
range_start_stop(start, stop) = start:stop
function range_start_step_length(a::AbstractFloat, step::AbstractFloat, len::Integer)
range_start_step_length(promote(a, step)..., len)
end
function range_start_step_length(a::Real, step::AbstractFloat, len::Integer)
range_start_step_length(float(a), step, len)
end
function range_start_step_length(a::AbstractFloat, step::Real, len::Integer)
range_start_step_length(a, float(step), len)
end
function range_start_step_length(a::T, step::T, len::Integer) where {T <: AbstractFloat}
_rangestyle(OrderStyle(T), ArithmeticStyle(T), a, step, len)
end
function range_start_step_length(a::T, step, len::Integer) where {T}
_rangestyle(OrderStyle(T), ArithmeticStyle(T), a, step, len)
end
_rangestyle(::Ordered, ::ArithmeticWraps, a::T, step::S, len::Integer) where {T,S} =
StepRange{typeof(a+zero(step)),S}(a, step, a+step*(len-1))
_rangestyle(::Any, ::Any, a::T, step::S, len::Integer) where {T,S} =
StepRangeLen{typeof(a+zero(step)),T,S}(a, step, len)
range_start_step_stop(start, step, stop) = start:step:stop
function range_error(start, step, stop, length)
hasstart = start !== nothing
hasstep = step !== nothing
hasstop = stop !== nothing
haslength = start !== nothing
hint = if hasstart && hasstep && hasstop && haslength
"Try specifying only three arguments"
elseif !hasstop && !haslength
"At least one of `length` or `stop` must be specified."
elseif !hasstep && !haslength
"At least one of `length` or `step` must be specified."
elseif !hasstart && !hasstop
"At least one of `start` or `stop` must be specified."
else
"Try specifying more arguments."
end
msg = """
Cannot construct range from arguments:
start = $start
step = $step
stop = $stop
length = $length
$hint
"""
throw(ArgumentError(msg))
end
## 1-dimensional ranges ##
"""
AbstractRange{T}
Supertype for ranges with elements of type `T`.
[`UnitRange`](@ref) and other types are subtypes of this.
"""
abstract type AbstractRange{T} <: AbstractArray{T,1} end
RangeStepStyle(::Type{<:AbstractRange}) = RangeStepIrregular()
RangeStepStyle(::Type{<:AbstractRange{<:Integer}}) = RangeStepRegular()
convert(::Type{T}, r::AbstractRange) where {T<:AbstractRange} = r isa T ? r : T(r)
## ordinal ranges
"""
OrdinalRange{T, S} <: AbstractRange{T}
Supertype for ordinal ranges with elements of type `T` with
spacing(s) of type `S`. The steps should be always-exact
multiples of [`oneunit`](@ref), and `T` should be a "discrete"
type, which cannot have values smaller than `oneunit`. For example,
`Integer` or `Date` types would qualify, whereas `Float64` would not (since this
type can represent values smaller than `oneunit(Float64)`.
[`UnitRange`](@ref), [`StepRange`](@ref), and other types are subtypes of this.
"""
abstract type OrdinalRange{T,S} <: AbstractRange{T} end
"""
AbstractUnitRange{T} <: OrdinalRange{T, T}
Supertype for ranges with a step size of [`oneunit(T)`](@ref) with elements of type `T`.
[`UnitRange`](@ref) and other types are subtypes of this.
"""
abstract type AbstractUnitRange{T} <: OrdinalRange{T,T} end
"""
StepRange{T, S} <: OrdinalRange{T, S}
Ranges with elements of type `T` with spacing of type `S`. The step
between each element is constant, and the range is defined in terms
of a `start` and `stop` of type `T` and a `step` of type `S`. Neither
`T` nor `S` should be floating point types. The syntax `a:b:c` with `b > 1`
and `a`, `b`, and `c` all integers creates a `StepRange`.
# Examples
```jldoctest
julia> collect(StepRange(1, Int8(2), 10))
5-element Vector{Int64}:
1
3
5
7
9
julia> typeof(StepRange(1, Int8(2), 10))
StepRange{Int64, Int8}
julia> typeof(1:3:6)
StepRange{Int64, Int64}
```
"""
struct StepRange{T,S} <: OrdinalRange{T,S}
start::T
step::S
stop::T
function StepRange{T,S}(start, step, stop) where {T,S}
sta = convert(T, start)
ste = convert(S, step)
sto = convert(T, stop)
new(sta, ste, steprange_last(sta,ste,sto))
end
end
# to make StepRange constructor inlineable, so optimizer can see `step` value
function steprange_last(start::T, step, stop) where T
if isa(start,AbstractFloat) || isa(step,AbstractFloat)
throw(ArgumentError("StepRange should not be used with floating point"))
end
if isa(start,Integer) && !isinteger(start + step)
throw(ArgumentError("StepRange{<:Integer} cannot have non-integer step"))
end
z = zero(step)
step == z && throw(ArgumentError("step cannot be zero"))
if stop == start
last = stop
else
if (step > z) != (stop > start)
last = steprange_last_empty(start, step, stop)
else
# Compute absolute value of difference between `start` and `stop`
# (to simplify handling both signed and unsigned T and checking for signed overflow):
absdiff, absstep = stop > start ? (stop - start, step) : (start - stop, -step)
# Compute remainder as a nonnegative number:
if T <: Signed && absdiff < zero(absdiff)
# handle signed overflow with unsigned rem
remain = convert(T, unsigned(absdiff) % absstep)
else
remain = absdiff % absstep
end
# Move `stop` closer to `start` if there is a remainder:
last = stop > start ? stop - remain : stop + remain
end
end
last
end
function steprange_last_empty(start::Integer, step, stop)
# empty range has a special representation where stop = start-1
# this is needed to avoid the wrap-around that can happen computing
# start - step, which leads to a range that looks very large instead
# of empty.
if step > zero(step)
last = start - oneunit(stop-start)
else
last = start + oneunit(stop-start)
end
last
end
# For types where x+oneunit(x) may not be well-defined
steprange_last_empty(start, step, stop) = start - step
StepRange{T}(start, step::S, stop) where {T,S} = StepRange{T,S}(start, step, stop)
StepRange(start::T, step::S, stop::T) where {T,S} = StepRange{T,S}(start, step, stop)
"""
UnitRange{T<:Real}
A range parameterized by a `start` and `stop` of type `T`, filled
with elements spaced by `1` from `start` until `stop` is exceeded.
The syntax `a:b` with `a` and `b` both `Integer`s creates a `UnitRange`.
# Examples
```jldoctest
julia> collect(UnitRange(2.3, 5.2))
3-element Vector{Float64}:
2.3
3.3
4.3
julia> typeof(1:10)
UnitRange{Int64}
```
"""
struct UnitRange{T<:Real} <: AbstractUnitRange{T}
start::T
stop::T
UnitRange{T}(start, stop) where {T<:Real} = new(start, unitrange_last(start,stop))
end
UnitRange(start::T, stop::T) where {T<:Real} = UnitRange{T}(start, stop)
unitrange_last(::Bool, stop::Bool) = stop
unitrange_last(start::T, stop::T) where {T<:Integer} =
ifelse(stop >= start, stop, convert(T,start-oneunit(stop-start)))
unitrange_last(start::T, stop::T) where {T} =
ifelse(stop >= start, convert(T,start+floor(stop-start)),
convert(T,start-oneunit(stop-start)))
unitrange(x) = UnitRange(x)
if isdefined(Main, :Base)
# Constant-fold-able indexing into tuples to functionally expose Base.tail and Base.front
function getindex(@nospecialize(t::Tuple), r::UnitRange)
@_inline_meta
r.start > r.stop && return ()
if r.start == 1
r.stop == length(t) && return t
r.stop == length(t)-1 && return front(t)
r.stop == length(t)-2 && return front(front(t))
elseif r.stop == length(t)
r.start == 2 && return tail(t)
r.start == 3 && return tail(tail(t))
end
return (eltype(t)[t[ri] for ri in r]...,)
end
end
"""
Base.OneTo(n)
Define an `AbstractUnitRange` that behaves like `1:n`, with the added
distinction that the lower limit is guaranteed (by the type system) to
be 1.
"""
struct OneTo{T<:Integer} <: AbstractUnitRange{T}
stop::T
OneTo{T}(stop) where {T<:Integer} = new(max(zero(T), stop))
function OneTo{T}(r::AbstractRange) where {T<:Integer}
throwstart(r) = (@_noinline_meta; throw(ArgumentError("first element must be 1, got $(first(r))")))
throwstep(r) = (@_noinline_meta; throw(ArgumentError("step must be 1, got $(step(r))")))
first(r) == 1 || throwstart(r)
step(r) == 1 || throwstep(r)
return new(max(zero(T), last(r)))
end
end
OneTo(stop::T) where {T<:Integer} = OneTo{T}(stop)
OneTo(r::AbstractRange{T}) where {T<:Integer} = OneTo{T}(r)
oneto(r) = OneTo(r)
## Step ranges parameterized by length
"""
StepRangeLen{T,R,S}(ref::R, step::S, len, [offset=1]) where {T,R,S}
StepRangeLen( ref::R, step::S, len, [offset=1]) where { R,S}
A range `r` where `r[i]` produces values of type `T` (in the second
form, `T` is deduced automatically), parameterized by a `ref`erence
value, a `step`, and the `len`gth. By default `ref` is the starting
value `r[1]`, but alternatively you can supply it as the value of
`r[offset]` for some other index `1 <= offset <= len`. In conjunction
with `TwicePrecision` this can be used to implement ranges that are
free of roundoff error.
"""
struct StepRangeLen{T,R,S} <: AbstractRange{T}
ref::R # reference value (might be smallest-magnitude value in the range)
step::S # step value
len::Int # length of the range
offset::Int # the index of ref
function StepRangeLen{T,R,S}(ref::R, step::S, len::Integer, offset::Integer = 1) where {T,R,S}
if T <: Integer && !isinteger(ref + step)
throw(ArgumentError("StepRangeLen{<:Integer} cannot have non-integer step"))
end
len >= 0 || throw(ArgumentError("length cannot be negative, got $len"))
1 <= offset <= max(1,len) || throw(ArgumentError("StepRangeLen: offset must be in [1,$len], got $offset"))
new(ref, step, len, offset)
end
end
StepRangeLen(ref::R, step::S, len::Integer, offset::Integer = 1) where {R,S} =
StepRangeLen{typeof(ref+zero(step)),R,S}(ref, step, len, offset)
StepRangeLen{T}(ref::R, step::S, len::Integer, offset::Integer = 1) where {T,R,S} =
StepRangeLen{T,R,S}(ref, step, len, offset)
## range with computed step
"""
LinRange{T}
A range with `len` linearly spaced elements between its `start` and `stop`.
The size of the spacing is controlled by `len`, which must
be an `Int`.
# Examples
```jldoctest
julia> LinRange(1.5, 5.5, 9)
9-element LinRange{Float64}:
1.5,2.0,2.5,3.0,3.5,4.0,4.5,5.0,5.5
```
Compared to using [`range`](@ref), directly constructing a `LinRange` should
have less overhead but won't try to correct for floating point errors:
```julia
julia> collect(range(-0.1, 0.3, length=5))
5-element Array{Float64,1}:
-0.1
0.0
0.1
0.2
0.3
julia> collect(LinRange(-0.1, 0.3, 5))
5-element Array{Float64,1}:
-0.1
-1.3877787807814457e-17
0.09999999999999999
0.19999999999999998
0.3
```
"""
struct LinRange{T} <: AbstractRange{T}
start::T
stop::T
len::Int
lendiv::Int
function LinRange{T}(start,stop,len) where T
len >= 0 || throw(ArgumentError("range($start, stop=$stop, length=$len): negative length"))
if len == 1
start == stop || throw(ArgumentError("range($start, stop=$stop, length=$len): endpoints differ"))
return new(start, stop, 1, 1)
end
lendiv = max(len-1, 1)
if T <: Integer && !iszero(mod(stop-start, lendiv))
throw(ArgumentError("LinRange{<:Integer} cannot have non-integer step"))
end
new(start,stop,len,lendiv)
end
end
function LinRange(start, stop, len::Integer)
T = typeof((stop-start)/len)
LinRange{T}(start, stop, len)
end
function range_start_stop_length(start::T, stop::S, len::Integer) where {T,S}
a, b = promote(start, stop)
range_start_stop_length(a, b, len)
end
range_start_stop_length(start::T, stop::T, len::Integer) where {T<:Real} = LinRange{T}(start, stop, len)
range_start_stop_length(start::T, stop::T, len::Integer) where {T} = LinRange{T}(start, stop, len)
range_start_stop_length(start::T, stop::T, len::Integer) where {T<:Integer} =
_linspace(float(T), start, stop, len)
## for Float16, Float32, and Float64 we hit twiceprecision.jl to lift to higher precision StepRangeLen
# for all other types we fall back to a plain old LinRange
_linspace(::Type{T}, start::Integer, stop::Integer, len::Integer) where T = LinRange{T}(start, stop, len)
function show(io::IO, r::LinRange)
print(io, "range(")
show(io, first(r))
print(io, ", stop=")
show(io, last(r))
print(io, ", length=")
show(io, length(r))
print(io, ')')
end
"""
`print_range(io, r)` prints out a nice looking range r in terms of its elements
as if it were `collect(r)`, dependent on the size of the
terminal, and taking into account whether compact numbers should be shown.
It figures out the width in characters of each element, and if they
end up too wide, it shows the first and last elements separated by a
horizontal ellipsis. Typical output will look like `1.0,2.0,3.0,…,4.0,5.0,6.0`.
`print_range(io, r, pre, sep, post, hdots)` uses optional
parameters `pre` and `post` characters for each printed row,
`sep` separator string between printed elements,
`hdots` string for the horizontal ellipsis.
"""
function print_range(io::IO, r::AbstractRange,
pre::AbstractString = " ",
sep::AbstractString = ",",
post::AbstractString = "",
hdots::AbstractString = ",\u2026,") # horiz ellipsis
# This function borrows from print_matrix() in show.jl
# and should be called by show and display
sz = displaysize(io)
if !haskey(io, :compact)
io = IOContext(io, :compact => true)
end
screenheight, screenwidth = sz[1] - 4, sz[2]
screenwidth -= length(pre) + length(post)
postsp = ""
sepsize = length(sep)
m = 1 # treat the range as a one-row matrix
n = length(r)
# Figure out spacing alignments for r, but only need to examine the
# left and right edge columns, as many as could conceivably fit on the
# screen, with the middle columns summarized by horz, vert, or diag ellipsis
maxpossiblecols = div(screenwidth, 1+sepsize) # assume each element is at least 1 char + 1 separator
colsr = n <= maxpossiblecols ? (1:n) : [1:div(maxpossiblecols,2)+1; (n-div(maxpossiblecols,2)):n]
rowmatrix = reshape(r[colsr], 1, length(colsr)) # treat the range as a one-row matrix for print_matrix_row
A = alignment(io, rowmatrix, 1:m, 1:length(rowmatrix), screenwidth, screenwidth, sepsize) # how much space range takes
if n <= length(A) # cols fit screen, so print out all elements
print(io, pre) # put in pre chars
print_matrix_row(io,rowmatrix,A,1,1:n,sep) # the entire range
print(io, post) # add the post characters
else # cols don't fit so put horiz ellipsis in the middle
# how many chars left after dividing width of screen in half
# and accounting for the horiz ellipsis
c = div(screenwidth-length(hdots)+1,2)+1 # chars remaining for each side of rowmatrix
alignR = reverse(alignment(io, rowmatrix, 1:m, length(rowmatrix):-1:1, c, c, sepsize)) # which cols of rowmatrix to put on the right
c = screenwidth - sum(map(sum,alignR)) - (length(alignR)-1)*sepsize - length(hdots)
alignL = alignment(io, rowmatrix, 1:m, 1:length(rowmatrix), c, c, sepsize) # which cols of rowmatrix to put on the left
print(io, pre) # put in pre chars
print_matrix_row(io, rowmatrix,alignL,1,1:length(alignL),sep) # left part of range
print(io, hdots) # horizontal ellipsis
print_matrix_row(io, rowmatrix,alignR,1,length(rowmatrix)-length(alignR)+1:length(rowmatrix),sep) # right part of range
print(io, post) # post chars
end
end
## interface implementations
size(r::AbstractRange) = (length(r),)
isempty(r::StepRange) =
(r.start != r.stop) & ((r.step > zero(r.step)) != (r.stop > r.start))
isempty(r::AbstractUnitRange) = first(r) > last(r)
isempty(r::StepRangeLen) = length(r) == 0
isempty(r::LinRange) = length(r) == 0
"""
step(r)
Get the step size of an [`AbstractRange`](@ref) object.
# Examples
```jldoctest
julia> step(1:10)
1
julia> step(1:2:10)
2
julia> step(2.5:0.3:10.9)
0.3
julia> step(range(2.5, stop=10.9, length=85))
0.1
```
"""
step(r::StepRange) = r.step
step(r::AbstractUnitRange{T}) where{T} = oneunit(T) - zero(T)
step(r::StepRangeLen) = r.step
step(r::StepRangeLen{T}) where {T<:AbstractFloat} = T(r.step)
step(r::LinRange) = (last(r)-first(r))/r.lendiv
step_hp(r::StepRangeLen) = r.step
step_hp(r::AbstractRange) = step(r)
unsafe_length(r::AbstractRange) = length(r) # generic fallback
function unsafe_length(r::StepRange)
n = Integer(div((r.stop - r.start) + r.step, r.step))
isempty(r) ? zero(n) : n
end
length(r::StepRange) = unsafe_length(r)
unsafe_length(r::AbstractUnitRange) = Integer(last(r) - first(r) + step(r))
unsafe_length(r::OneTo) = Integer(r.stop - zero(r.stop))
length(r::AbstractUnitRange) = unsafe_length(r)
length(r::OneTo) = unsafe_length(r)
length(r::StepRangeLen) = r.len
length(r::LinRange) = r.len
# Needed to fold the `firstindex` call in SimdLoop.simd_index
firstindex(::UnitRange) = 1
firstindex(::StepRange) = 1
firstindex(::LinRange) = 1
function length(r::StepRange{T}) where T<:Union{Int,UInt,Int64,UInt64,Int128,UInt128}
isempty(r) && return zero(T)
if r.step > 1
return checked_add(convert(T, div(unsigned(r.stop - r.start), r.step)), one(T))
elseif r.step < -1
return checked_add(convert(T, div(unsigned(r.start - r.stop), -r.step)), one(T))
elseif r.step > 0
return checked_add(div(checked_sub(r.stop, r.start), r.step), one(T))
else
return checked_add(div(checked_sub(r.start, r.stop), -r.step), one(T))
end
end
function length(r::AbstractUnitRange{T}) where T<:Union{Int,Int64,Int128}
@_inline_meta
checked_add(checked_sub(last(r), first(r)), one(T))
end
length(r::OneTo{T}) where {T<:Union{Int,Int64}} = T(r.stop)
length(r::AbstractUnitRange{T}) where {T<:Union{UInt,UInt64,UInt128}} =
r.stop < r.start ? zero(T) : checked_add(last(r) - first(r), one(T))
# some special cases to favor default Int type
let smallint = (Int === Int64 ?
Union{Int8,UInt8,Int16,UInt16,Int32,UInt32} :
Union{Int8,UInt8,Int16,UInt16})
global length
function length(r::StepRange{<:smallint})
isempty(r) && return Int(0)
div(Int(r.stop)+Int(r.step) - Int(r.start), Int(r.step))
end
length(r::AbstractUnitRange{<:smallint}) = Int(last(r)) - Int(first(r)) + 1
length(r::OneTo{<:smallint}) = Int(r.stop)
end
first(r::OrdinalRange{T}) where {T} = convert(T, r.start)
first(r::OneTo{T}) where {T} = oneunit(T)
first(r::StepRangeLen) = unsafe_getindex(r, 1)
first(r::LinRange) = r.start
last(r::OrdinalRange{T}) where {T} = convert(T, r.stop)
last(r::StepRangeLen) = unsafe_getindex(r, length(r))
last(r::LinRange) = r.stop
minimum(r::AbstractUnitRange) = isempty(r) ? throw(ArgumentError("range must be non-empty")) : first(r)
maximum(r::AbstractUnitRange) = isempty(r) ? throw(ArgumentError("range must be non-empty")) : last(r)
minimum(r::AbstractRange) = isempty(r) ? throw(ArgumentError("range must be non-empty")) : min(first(r), last(r))
maximum(r::AbstractRange) = isempty(r) ? throw(ArgumentError("range must be non-empty")) : max(first(r), last(r))
"""
argmin(r::AbstractRange)
Ranges can have multiple minimal elements. In that case
`argmin` will return a minimal index, but not necessarily the
first one.
"""
function argmin(r::AbstractRange)
if isempty(r)
throw(ArgumentError("range must be non-empty"))
elseif step(r) > 0
firstindex(r)
else
first(searchsorted(r, last(r)))
end
end
"""
argmax(r::AbstractRange)
Ranges can have multiple maximal elements. In that case
`argmax` will return a maximal index, but not necessarily the
first one.
"""
function argmax(r::AbstractRange)
if isempty(r)
throw(ArgumentError("range must be non-empty"))
elseif step(r) > 0
first(searchsorted(r, last(r)))
else
firstindex(r)
end
end
extrema(r::AbstractRange) = (minimum(r), maximum(r))
# Ranges are immutable
copy(r::AbstractRange) = r
## iteration
function iterate(r::Union{LinRange,StepRangeLen}, i::Int=1)
@_inline_meta
length(r) < i && return nothing
unsafe_getindex(r, i), i + 1
end
iterate(r::OrdinalRange) = isempty(r) ? nothing : (first(r), first(r))
function iterate(r::OrdinalRange{T}, i) where {T}
@_inline_meta
i == last(r) && return nothing
next = convert(T, i + step(r))
(next, next)
end
## indexing
_in_unit_range(v::UnitRange, val, i::Integer) = i > 0 && val <= v.stop && val >= v.start
function getindex(v::UnitRange{T}, i::Integer) where T
@_inline_meta
val = convert(T, v.start + (i - 1))
@boundscheck _in_unit_range(v, val, i) || throw_boundserror(v, i)
val
end
const OverflowSafe = Union{Bool,Int8,Int16,Int32,Int64,Int128,
UInt8,UInt16,UInt32,UInt64,UInt128}
function getindex(v::UnitRange{T}, i::Integer) where {T<:OverflowSafe}
@_inline_meta
val = v.start + (i - 1)
@boundscheck _in_unit_range(v, val, i) || throw_boundserror(v, i)
val % T
end
function getindex(v::OneTo{T}, i::Integer) where T
@_inline_meta
@boundscheck ((i > 0) & (i <= v.stop)) || throw_boundserror(v, i)
convert(T, i)
end
function getindex(v::AbstractRange{T}, i::Integer) where T
@_inline_meta
ret = convert(T, first(v) + (i - 1)*step_hp(v))
ok = ifelse(step(v) > zero(step(v)),
(ret <= last(v)) & (ret >= first(v)),
(ret <= first(v)) & (ret >= last(v)))
@boundscheck ((i > 0) & ok) || throw_boundserror(v, i)
ret
end
function getindex(r::Union{StepRangeLen,LinRange}, i::Integer)
@_inline_meta
@boundscheck checkbounds(r, i)
unsafe_getindex(r, i)
end
# This is separate to make it useful even when running with --check-bounds=yes
function unsafe_getindex(r::StepRangeLen{T}, i::Integer) where T
u = i - r.offset
T(r.ref + u*r.step)
end
function _getindex_hiprec(r::StepRangeLen, i::Integer) # without rounding by T
u = i - r.offset
r.ref + u*r.step
end
function unsafe_getindex(r::LinRange, i::Integer)
lerpi(i-1, r.lendiv, r.start, r.stop)
end
function lerpi(j::Integer, d::Integer, a::T, b::T) where T
@_inline_meta
t = j/d
T((1-t)*a + t*b)
end
getindex(r::AbstractRange, ::Colon) = copy(r)
function getindex(r::AbstractUnitRange, s::AbstractUnitRange{<:Integer})
@_inline_meta
@boundscheck checkbounds(r, s)
f = first(r)
st = oftype(f, f + first(s)-1)
range(st, length=length(s))
end
function getindex(r::OneTo{T}, s::OneTo) where T
@_inline_meta
@boundscheck checkbounds(r, s)
OneTo(T(s.stop))
end
function getindex(r::AbstractUnitRange, s::StepRange{<:Integer})
@_inline_meta
@boundscheck checkbounds(r, s)
st = oftype(first(r), first(r) + s.start-1)
range(st, step=step(s), length=length(s))
end
function getindex(r::StepRange, s::AbstractRange{<:Integer})
@_inline_meta
@boundscheck checkbounds(r, s)
st = oftype(r.start, r.start + (first(s)-1)*step(r))
range(st, step=step(r)*step(s), length=length(s))
end
function getindex(r::StepRangeLen{T}, s::OrdinalRange{<:Integer}) where {T}
@_inline_meta
@boundscheck checkbounds(r, s)
# Find closest approach to offset by s
ind = LinearIndices(s)
offset = max(min(1 + round(Int, (r.offset - first(s))/step(s)), last(ind)), first(ind))
ref = _getindex_hiprec(r, first(s) + (offset-1)*step(s))
return StepRangeLen{T}(ref, r.step*step(s), length(s), offset)
end
function getindex(r::LinRange{T}, s::OrdinalRange{<:Integer}) where {T}
@_inline_meta
@boundscheck checkbounds(r, s)
vfirst = unsafe_getindex(r, first(s))
vlast = unsafe_getindex(r, last(s))
return LinRange{T}(vfirst, vlast, length(s))
end
show(io::IO, r::AbstractRange) = print(io, repr(first(r)), ':', repr(step(r)), ':', repr(last(r)))
show(io::IO, r::UnitRange) = print(io, repr(first(r)), ':', repr(last(r)))
show(io::IO, r::OneTo) = print(io, "Base.OneTo(", r.stop, ")")
function ==(r::T, s::T) where {T<:AbstractRange}
isempty(r) && return isempty(s)
_has_length_one(r) && return _has_length_one(s) & (first(r) == first(s))
(first(r) == first(s)) & (step(r) == step(s)) & (last(r) == last(s))
end
function ==(r::OrdinalRange, s::OrdinalRange)
isempty(r) && return isempty(s)
_has_length_one(r) && return _has_length_one(s) & (first(r) == first(s))
(first(r) == first(s)) & (step(r) == step(s)) & (last(r) == last(s))
end
==(r::T, s::T) where {T<:Union{StepRangeLen,LinRange}} =
(isempty(r) & isempty(s)) | ((first(r) == first(s)) & (length(r) == length(s)) & (last(r) == last(s)))
function ==(r::Union{StepRange{T},StepRangeLen{T,T}}, s::Union{StepRange{T},StepRangeLen{T,T}}) where {T}
isempty(r) && return isempty(s)
_has_length_one(r) && return _has_length_one(s) & (first(r) == first(s))
(first(r) == first(s)) & (step(r) == step(s)) & (last(r) == last(s))
end
_has_length_one(r::OrdinalRange) = first(r) == last(r)
_has_length_one(r::AbstractRange) = isone(length(r))
function ==(r::AbstractRange, s::AbstractRange)
lr = length(r)
if lr != length(s)
return false
elseif iszero(lr)
return true
end
yr, ys = iterate(r), iterate(s)
while yr !== nothing
yr[1] == ys[1] || return false
yr, ys = iterate(r, yr[2]), iterate(s, ys[2])
end
return true
end
intersect(r::OneTo, s::OneTo) = OneTo(min(r.stop,s.stop))
union(r::OneTo, s::OneTo) = OneTo(max(r.stop,s.stop))
intersect(r::AbstractUnitRange{<:Integer}, s::AbstractUnitRange{<:Integer}) = max(first(r),first(s)):min(last(r),last(s))
intersect(i::Integer, r::AbstractUnitRange{<:Integer}) = range(max(i, first(r)), length=in(i, r))
intersect(r::AbstractUnitRange{<:Integer}, i::Integer) = intersect(i, r)
function intersect(r::AbstractUnitRange{<:Integer}, s::StepRange{<:Integer})
T = promote_type(eltype(r), eltype(s))
if isempty(s)
StepRange{T}(first(r), +step(s), first(r)-step(s))
else
sta, ste, sto = first_step_last_ascending(s)
lo = first(r)
hi = last(r)
i0 = max(sta, lo + mod(sta - lo, ste))
i1 = min(sto, hi - mod(hi - sta, ste))
StepRange{T}(i0, ste, i1)
end
end
function first_step_last_ascending(r::StepRange)
if step(r) < zero(step(r))
last(r), -step(r), first(r)
else
first(r), +step(r), last(r)
end
end
function intersect(r::StepRange{<:Integer}, s::AbstractUnitRange{<:Integer})
if step(r) < 0
reverse(intersect(s, reverse(r)))
else
intersect(s, r)
end
end
function intersect(r::StepRange, s::StepRange)
T = promote_type(eltype(r), eltype(s))
S = promote_type(typeof(step(r)), typeof(step(s)))
if isempty(r) || isempty(s)
return StepRange{T,S}(first(r), step(r), first(r)-step(r))
end
start1, step1, stop1 = first_step_last_ascending(r)
start2, step2, stop2 = first_step_last_ascending(s)
a = lcm(step1, step2)
g, x, y = gcdx(step1, step2)
if !iszero(rem(start1 - start2, g))
# Unaligned, no overlap possible.
if step(r) < zero(step(r))
return StepRange{T,S}(stop1, -a, stop1+a)
else
return StepRange{T,S}(start1, a, start1-a)
end
end
z = div(start1 - start2, g)
b = start1 - x * z * step1
# Possible points of the intersection of r and s are
# ..., b-2a, b-a, b, b+a, b+2a, ...
# Determine where in the sequence to start and stop.
m = max(start1 + mod(b - start1, a), start2 + mod(b - start2, a))
n = min(stop1 - mod(stop1 - b, a), stop2 - mod(stop2 - b, a))
step(r) < zero(step(r)) ? StepRange{T,S}(n, -a, m) : StepRange{T,S}(m, a, n)
end
function intersect(r1::AbstractRange, r2::AbstractRange, r3::AbstractRange, r::AbstractRange...)
i = intersect(intersect(r1, r2), r3)
for t in r
i = intersect(i, t)
end
i
end
# _findin (the index of intersection)
function _findin(r::AbstractRange{<:Integer}, span::AbstractUnitRange{<:Integer})
local ifirst
local ilast
fspan = first(span)
lspan = last(span)
fr = first(r)
lr = last(r)
sr = step(r)