first commit

Project.toml

@@ -4,10 +4,12 @@ authors = ["Tianyi Pu <[email protected]> and contributors"]
 version = "1.0.0-DEV"
 
 [compat]
+Aqua = "0.8"
 julia = "1"
 
 [extras]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test"]
+test = ["Aqua", "Test"]

docs/.gitignore

@@ -0,0 +1,2 @@
+build/
+site/

docs/Project.toml

@@ -0,0 +1,2 @@
+[deps]
+Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"

docs/make.jl

@@ -0,0 +1,15 @@
+using Documenter
+using EltypeExtensions
+
+makedocs(
+    sitename = "EltypeExtensions",
+    format = Documenter.HTML(),
+    modules = [EltypeExtensions]
+)
+
+# Documenter can also automatically deploy documentation to gh-pages.
+# See "Hosting Documentation" and deploydocs() in the Documenter manual
+# for more information.
+#=deploydocs(
+    repo = "<repository url>"
+)=#

docs/src/docstring.md

@@ -0,0 +1,4 @@
+# Docstrings
+```@autodocs
+Modules = [EltypeExtensions]
+```

docs/src/index.md

@@ -0,0 +1,30 @@
+# EltypeExtensions.jl
+
+EltypeExtensions.jl is a mini toolbox for eltype-related conversions. The motivation of this package comes from manipulating (nested) arrays with different eltypes. However if you have any reasonable idea that works on other collections, feel free to write an issue/pull request.
+
+We note that this package has some overlap with TypeUtils.jl and Unitless.jl.
+
+## Guides
+
+### `basetype` and `precisiontype`
+The `basetype` is used for nested collections, where `eltype` is repeatedly applied until the bottom. `precisiontype` has a similar idea, but goes deeper when possible. `precisiontype` is used to manipulate the accuracy of (nested) collections.
+```@setup 1
+using EltypeExtensions
+```
+```@example 1
+basetype(Set{Matrix{Vector{Matrix{Complex{Rational{Int}}}}}})
+precisiontype(Set{Matrix{Vector{Matrix{Complex{Rational{Int}}}}}})
+```
+
+### Method naming convention
+- `sometype(T)` gets the `sometype` of type `T`.
+- `sometype(x) = sometype(typeof(x))` is also provided for convenience.
+- `_to_sometype(T,S)` converts the type `S` to have the `sometype` of `T`.
+- `someconvert(T,A)` converts `A` to have the `sometype` of `T`.
+
+where `some` can be `el`, `base` and `precision`.
+
+### On `precisionconvert`
+Since some types (e.g. `BigFloat`) can have variable precision, `precisionconvert` accepts a third argument `prec` which specifies the precision. `prec` defaults to `precision(T)` and has no effect when `T` has a const precision.
+
+When `T` is an integer, the conversion will dig into `Rational` as well. In contrast, since `Rational` as a whole is more "precise" than an integer, `precisiontype` doesn't unwrap `Rational`.

src/EltypeExtensions.jl

@@ -1,5 +1,134 @@
 module EltypeExtensions
 
-# Write your package code here.
+import Base: convert
+
+export elconvert, basetype, baseconvert, precisiontype, precisionconvert
+
+"""
+    elconvert(T, A)
+
+Similar to `convert(T, A)`, but `T` refers to the eltype.
+
+# Examples
+```jldoctest; setup = :(using EltypeExtensions: elconvert)
+julia> elconvert(Float64, 1:10)
+1.0:1.0:10.0
+
+julia> typeof(elconvert(Float64, rand(Int, 3, 3)))
+$(repr("text/plain", Matrix{Float64}))
+```
+"""
+elconvert(::Type{T}, A::AbstractArray) where T = AbstractArray{T}(A)
+elconvert(::Type{T}, A::AbstractRange) where T = AbstractRange{T}(A)
+elconvert(::Type{T}, A::AbstractSet) where T = AbstractSet{T}(A)
+
+"""
+    _to_eltype(T, S)
+
+Convert type `S` to have the `eltype` of `T`.
+"""
+_to_eltype(::Type{T}, ::Type{Array{S,N}}) where {T,S,N} = Array{T,N}
+_to_eltype(::Type{T}, ::Type{Set}) where T = Set{T}
+_to_eltype(::Type{T}, ::Type{S}) where {T,S} = Base.return_types(elconvert, (Type{T}, S))
+
+nutype(x) = nutype(typeof(x))
+nutype(T::Type) = throw(MethodError(nutype, T))
+
+"""
+    basetype(T::Type)
+
+Recursively apply `eltype` to `T` until convergence.
+
+# Examples
+```jldoctest; setup = :(using EltypeExtensions: basetype)
+julia> basetype(Matrix{BitArray})
+Bool
+
+julia> basetype(Vector{Set{Complex{Float64}}})
+$(repr("text/plain", Complex{Float64}))
+
+julia> basetype([1:n for n in 1:10])
+Int64
+```
+"""
+basetype(x) = basetype(typeof(x))
+basetype(::Type{T}) where T = eltype(T) == T ? T : basetype(eltype(T))
+
+"""
+    _to_basetype(T::Type, S::Type)
+
+Convert type `S` to have the [`basetype`](@ref) of `T`.
+"""
+_to_basetype(::Type{T}, ::Type{S}) where {T,S} = eltype(S) == S ? T : _to_eltype(_to_basetype(T, eltype(S)), S)
+
+"""
+    baseconvert(T::Type, A)
+
+Similar to `convert(T, A)`, but `T` refers to the [`basetype`](@ref).
+"""
+baseconvert(::Type{T}, A::S) where {T,S} = convert(_to_basetype(T,S), A)
+
+"""
+    precisiontype(T::Type)
+
+Returns the type that decides the precision of `T`. The difference from [`basetype`](@ref) is that `precisiontype` unwraps composite basetypes such as `Complex` and that `precisiontype` is not generalised.
+
+# Examples
+```jldoctest; setup = :(using EltypeExtensions: precisiontype)
+julia> precisiontype(Complex{Float32})
+Float32
+
+julia> precisiontype(Matrix{ComplexF64})
+Float64
+```
+"""
+precisiontype(x) = precisiontype(typeof(x))
+precisiontype(::Type{T}) where T<:Real = T
+precisiontype(::Type{Complex{T}}) where T = T
+precisiontype(::Type{T}) where T = eltype(T) == T ? throw(MethodError(precisiontype, T)) : precisiontype(basetype(T))
+
+"""
+    _to_precisiontype(T::Type, S::Type)
+
+Convert type `S` to have the [`precisiontype`](@ref) of `T`. An exception is that if `T<:Integer`, then `Rational` will also be unwrapped.
+
+# Examples
+```jldoctest; setup = :(using EltypeExtensions: _to_precisiontype)
+julia> _to_precisiontype(Float64, Complex{Rational{Int}})
+$(repr("text/plain", Complex{Float64}))
+
+julia> _to_precisiontype(BigFloat, Matrix{Complex{Bool}})
+$(repr("text/plain", Matrix{Complex{BigFloat}}))
+
+julia> _to_precisiontype(Int, Complex{Rational{BigInt}})
+Complex{Rational{Int64}}
+```
+"""
+_to_precisiontype(::Type{T}, ::Type{Complex{S}}) where {T,S} = Complex{_to_precisiontype(T,S)}
+_to_precisiontype(::Type{T}, ::Type{<:Rational}) where T<:Integer = Rational{T}
+_to_precisiontype(::Type{T}, ::Type{S}) where {T,S} = eltype(S) == S ? T : _to_eltype(_to_precisiontype(T, eltype(S)), S)
+
+"""
+    precisionconvert(T::Type, A, prec=precision(T))
+
+Convert `A` to have the [`precisiontype`](@ref) of `T`. If `T` has adjustable precision such as `BigFloat`, the precision can be specified by `prec`, otherwise `prec` takes no effect.
+
+# Examples
+```jldoctest; setup = :(using EltypeExtensions: precisionconvert)
+julia> precisionconvert(BigFloat, 1//3+im, 128)
+0.3333333333333333333333333333333333333338 + 1.0im
+
+julia> precisionconvert(Float16, [[m/n for n in 1:3] for m in 1:3])
+3-element Vector{Vector{Float16}}:
+ [1.0, 0.5, 0.3333]
+ [2.0, 1.0, 0.6665]
+ [3.0, 1.5, 1.0]
+```
+"""
+precisionconvert(T,A) = precisionconvert(T,A,precision(T))
+precisionconvert(::Type{T}, A::S, prec) where {T,S} = convert(_to_precisiontype(T,S), A)
+precisionconvert(::Type{BigFloat}, x::Real, prec) = BigFloat(x, prec)
+precisionconvert(::Type{BigFloat}, x::Complex, prec) = Complex(BigFloat(real(x), prec), BigFloat(imag(x), prec))
+precisionconvert(::Type{BigFloat}, A, prec) = precisionconvert.(BigFloat, A, prec)
 
 end

test/runtests.jl

@@ -1,6 +1,11 @@
 using EltypeExtensions
 using Test
+using Aqua
 
 @testset "EltypeExtensions.jl" begin
     # Write your tests here.
 end
+
+@testset "Aqua" begin
+    Aqua.test_all(EltypeExtensions)
+end