kalmar/Groups.jl
1
0
Fork 0
mirror of https://github.com/kalmarek/Groups.jl.git synced 2024-11-19 06:30:29 +01:00
Code Issues Releases Wiki Activity

uncomplicate Transvections

Browse Source
This commit is contained in:
Marek Kaluba 2021-08-13 16:19:27 +02:00
parent 960a70afef
commit baec864437
No known key found for this signature in database
GPG Key ID: 8BF1A3855328FC15
1 changed files with 11 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
src/groups/transvections.jl
View File

@ -1,28 +1,18 @@
struct Transvection <: GSymbol
id::Symbol
ij::UInt8
i::UInt16
j::UInt16
inv::Bool
function Transvection(id::Symbol, i::Integer, j::Integer, inv = false)
@assert id in (:ϱ, :λ)
@boundscheck @assert 0 < i <= (typemax(UInt8) >> 4)
@boundscheck @assert 0 < j <= (typemax(UInt8) >> 4)
return new(id, (convert(UInt8, i) << 4) + convert(UInt8, j), inv)
return new(id, i, j, inv)
end
end
ϱ(i, j) = Transvection(:ϱ, i, j)
λ(i, j) = Transvection(:λ, i, j)
_tophalf(ij::UInt8) = (ij & 0xf0) >> 4
_bothalf(ij::UInt8) = (ij & 0x0f)
function Base.getproperty(t::Transvection, s::Symbol)
s === :i && return _tophalf(t.ij)
s === :j && return _bothalf(t.ij)
return Core.getfield(t, s)
end
function Base.show(io::IO, t::Transvection)
id = if t.id === :ϱ
'ϱ'
@ -33,18 +23,18 @@ function Base.show(io::IO, t::Transvection)
t.inv && print(io, "^-1")
end
Base.inv(t::Transvection) =
Transvection(t.id, _tophalf(t.ij), _bothalf(t.ij), !t.inv)
Base.inv(t::Transvection) = Transvection(t.id, t.i, t.j, !t.inv)
Base.:(==)(t::Transvection, s::Transvection) =
t.id === s.id && t.ij == s.ij && t.inv == s.inv
Base.hash(t::Transvection, h::UInt) = hash(t.id, hash(t.ij, hash(t.inv, h)))
t.id === s.id && t.i == s.i && t.j == s.j && t.inv == s.inv
Base.hash(t::Transvection, h::UInt) = hash(hash(t.id, hash(t.i)), hash(t.j, hash(t.inv, h)))
Base.@propagate_inbounds @inline function evaluate!(
v::NTuple{T, N},
v::NTuple{T,N},
t::Transvection,
tmp=one(first(v))
) where {T, N}
tmp = one(first(v)),
) where {T,N}
i, j = t.i, t.j
@assert 1 ≤ i ≤ length(v) && 1 ≤ j ≤ length(v)
@ -102,5 +92,4 @@ Base.inv(p::PermRightAut) = PermRightAut(invperm(p.perm))
Base.:(==)(p::PermRightAut, q::PermRightAut) = p.perm == q.perm
Base.hash(p::PermRightAut, h::UInt) = hash(p.perm, hash(PermRightAut, h))
evaluate!(v::NTuple{T,N}, p::PermRightAut, tmp=nothing) where {T,N} = v[p.perm]
end
evaluate!(v::NTuple{T,N}, p::PermRightAut, tmp = nothing) where {T,N} = v[p.perm]