kalmar/Groups.jl
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multiple dispatch style solutions for * and inv for rings

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kalmar 2017-07-21 13:30:35 +02:00
parent ca23485b5e
commit 83f9ed61b8
1 changed files with 21 additions and 21 deletions
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40
src/DirectProducts.jl
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@ -161,23 +161,25 @@ end
#
###############################################################################
function direct_mult(g::DirectProductGroupElem, h::DirectProductGroupElem)
G = parent(g)
# G == parent(h) || throw("Can't multiply elements from different groups: $G, $parent(h)")
if isa(first(G.factors), Ring)
return G(.+(g.elts,h.elts))
else
return G(.*(g.elts,h.elts))
end
end
doc"""
*(g::DirectProductGroupElem, h::DirectProductGroupElem)
> Return the direct-product group operation of elements, i.e. component-wise
> operation as defined by `operations` field of the parent object.
"""
(*)(g::DirectProductGroupElem, h::DirectProductGroupElem) = direct_mult(g,h)
# TODO: dirty hack around `+/*` operations
function *{T<:GroupElem}(g::DirectProductGroupElem{T}, h::DirectProductGroupElem{T}, check::Bool=true)
if check
parent(g) == parent(h) || throw("Can not multiply elements of different groups!")
end
return DirectProductGroupElem([a*b for (a,b) in zip(g.elts,h.elts)])
end
function *{T<:RingElem}(g::DirectProductGroupElem{T}, h::DirectProductGroupElem{T}, check::Bool=true)
if check
parent(g) == parent(h) || throw("Can not multiply elements of different groups!")
end
return DirectProductGroupElem([a+b for (a,b) in zip(g.elts,h.elts)])
end
###############################################################################
#
@ -188,16 +190,14 @@ doc"""
doc"""
inv(g::DirectProductGroupElem)
> Return the inverse of the given element in the direct product group.
"""
# TODO: dirty hack around `+` operation
function inv(g::DirectProductGroupElem)
G = parent(g)
if isa(first(G.factors), Ring)
return DirectProductGroupElem([-a for a in g.elts])
else
# TODO: dirty hack around `+/*` operation
function inv{T<:GroupElem}(g::DirectProductGroupElem{T})
return DirectProductGroupElem([inv(a) for a in g.elts])
end
end
function inv{T<:RingElem}(g::DirectProductGroupElem{T})
return DirectProductGroupElem([-a for a in g.elts])
end
###############################################################################