1
0
mirror of https://github.com/kalmarek/Groups.jl.git synced 2024-10-15 15:25:36 +02:00

uncomplicate Transvections

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

View File

@ -1,28 +1,18 @@
struct Transvection <: GSymbol struct Transvection <: GSymbol
id::Symbol id::Symbol
ij::UInt8 i::UInt16
j::UInt16
inv::Bool inv::Bool
function Transvection(id::Symbol, i::Integer, j::Integer, inv = false) function Transvection(id::Symbol, i::Integer, j::Integer, inv = false)
@assert id in (:ϱ, ) @assert id in (:ϱ, )
@boundscheck @assert 0 < i <= (typemax(UInt8) >> 4) return new(id, i, j, inv)
@boundscheck @assert 0 < j <= (typemax(UInt8) >> 4)
return new(id, (convert(UInt8, i) << 4) + convert(UInt8, j), inv)
end end
end end
ϱ(i, j) = Transvection(:ϱ, i, j) ϱ(i, j) = Transvection(:ϱ, i, j)
λ(i, j) = Transvection(, i, j) λ(i, j) = Transvection(, 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) function Base.show(io::IO, t::Transvection)
id = if t.id === :ϱ id = if t.id === :ϱ
'ϱ' 'ϱ'
@ -33,17 +23,17 @@ function Base.show(io::IO, t::Transvection)
t.inv && print(io, "^-1") t.inv && print(io, "^-1")
end end
Base.inv(t::Transvection) = Base.inv(t::Transvection) = Transvection(t.id, t.i, t.j, !t.inv)
Transvection(t.id, _tophalf(t.ij), _bothalf(t.ij), !t.inv)
Base.:(==)(t::Transvection, s::Transvection) = Base.:(==)(t::Transvection, s::Transvection) =
t.id === s.id && t.ij == s.ij && t.inv == s.inv t.id === s.id && t.i == s.i && t.j == s.j && t.inv == s.inv
Base.hash(t::Transvection, h::UInt) = hash(t.id, hash(t.ij, hash(t.inv, h)))
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!( Base.@propagate_inbounds @inline function evaluate!(
v::NTuple{T,N}, v::NTuple{T,N},
t::Transvection, t::Transvection,
tmp=one(first(v)) tmp = one(first(v)),
) where {T,N} ) where {T,N}
i, j = t.i, t.j i, j = t.i, t.j
@assert 1 i length(v) && 1 j length(v) @assert 1 i length(v) && 1 j length(v)
@ -103,4 +93,3 @@ Base.:(==)(p::PermRightAut, q::PermRightAut) = p.perm == q.perm
Base.hash(p::PermRightAut, h::UInt) = hash(p.perm, hash(PermRightAut, h)) 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] evaluate!(v::NTuple{T,N}, p::PermRightAut, tmp = nothing) where {T,N} = v[p.perm]
end