kalmar/Groups.jl
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replace! and replace_all! for GWords

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kalmar 2017-01-25 11:32:12 +01:00
parent b0b129fd8b
commit 76ea736165
1 changed files with 30 additions and 0 deletions
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src/Groups.jl
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@ -199,6 +199,36 @@ function Base.findnext(W::GWord, Z::GWord, i::Integer)
end
Base.findfirst(W::GWord, Z::GWord) = findnext(W, Z, 1)
function replace!(W::GWord, index, toreplace::GWord, replacement::GWord; asserts=true)
n = length(toreplace.symbols)
if asserts
@assert is_subsymbol(toreplace.symbols[1], W.symbols[index])
@assert W.symbols[index+1:index+n-2] == toreplace.symbols[2:end-1]
@assert is_subsymbol(toreplace.symbols[end], W.symbols[index+n-1])
end
first = W.symbols[index]*inv(toreplace.symbols[1])
last = W.symbols[index+n-1]*inv(toreplace.symbols[end])
replacement = first*replacement*last
splice!(W.symbols, index:index+n-1, replacement.symbols)
Groups.freegroup_reduce!(W)
return W
end
function replace_all!{T}(W::GWord{T}, subst_dict::Dict{GWord{T}, GWord{T}})
reduced = true
for toreplace in reverse!(sort!(collect(keys(subst_dict))))
replacement = subst_dict[toreplace]
i = findfirst(W, toreplace)
while i ≠ 0
replace!(W,i,toreplace, replacement)
i = findnext(W, toreplace, i-1)
end
end
return W
end
include("free_groups.jl")
include("automorphism_groups.jl")