split definitions of action to a separate file

groups/Allgroups.jl

@@ -4,6 +4,7 @@ using PropertyT
 using AbstractAlgebra
 using Nemo
 using Groups
+using GroupRings
 
 export PropertyTGroup, SymmetrizedGroup, GAPGroup,
     SpecialLinearGroup,
@@ -50,5 +51,6 @@ end
 include("mappingclassgroup.jl")
 include("higman.jl")
 include("caprace.jl")
+include("actions.jl")
 
 end # of module PropertyTGroups

groups/actions.jl

@@ -0,0 +1,92 @@
+function (p::perm)(A::GroupRingElem)
+    RG = parent(A)
+    result = zero(RG, eltype(A.coeffs))
+    
+    for (idx, c) in enumerate(A.coeffs)
+        if c!= zero(eltype(A.coeffs))
+            result[p(RG.basis[idx])] = c
+        end
+    end
+    return result
+end
+
+###############################################################################
+#
+#  Action of WreathProductElems on Nemo.MatElem
+#
+###############################################################################
+
+function matrix_emb(n::DirectProductGroupElem, p::perm)
+    Id = parent(n.elts[1])()
+    elt = diagm([(-1)^(el == Id ? 0 : 1) for el in n.elts])
+    return elt[:, p.d]
+end
+
+function (g::WreathProductElem)(A::MatElem)
+    g_inv = inv(g)
+    G = matrix_emb(g.n, g_inv.p)
+    G_inv = matrix_emb(g_inv.n, g.p)
+    M = parent(A)
+    return M(G)*A*M(G_inv)
+end
+
+import Base.*
+
+doc"""
+    *(x::AbstractAlgebra.MatElem, P::Generic.perm)
+> Apply the pemutation $P$ to the rows of the matrix $x$ and return the result.
+"""
+function *(x::AbstractAlgebra.MatElem, P::Generic.perm)
+   z = similar(x)
+   m = rows(x)
+   n = cols(x)
+   for i = 1:m
+      for j = 1:n
+         z[i, j] = x[i,P[j]]
+      end
+   end
+   return z
+end
+
+function (p::perm)(A::MatElem)
+    length(p.d) == A.r == A.c || throw("Can't act via $p on matrix of size ($(A.r), $(A.c))")
+    return p*A*inv(p)
+end
+
+###############################################################################
+#
+#  Action of WreathProductElems on AutGroupElem
+#
+###############################################################################
+
+function AutFG_emb(A::AutGroup, g::WreathProductElem)
+    isa(A.objectGroup, FreeGroup) || throw("Not an Aut(Fₙ)")
+    parent(g).P.n == length(A.objectGroup.gens) || throw("No natural embedding of $(parent(g)) into $A")
+    elt = A()
+    Id = parent(g.n.elts[1])()
+    flips = Groups.AutSymbol[Groups.flip_autsymbol(i) for i in 1:length(g.p.d) if g.n.elts[i] != Id]
+    Groups.r_multiply!(elt, flips, reduced=false)
+    Groups.r_multiply!(elt, [Groups.perm_autsymbol(g.p)])
+    return elt
+end
+
+function AutFG_emb(A::AutGroup, p::perm)
+    isa(A.objectGroup, FreeGroup) || throw("Not an Aut(Fₙ)")
+    parent(p).n == length(A.objectGroup.gens) || throw("No natural embedding of $(parent(p)) into $A")
+    return A(Groups.perm_autsymbol(p))
+end
+
+function (g::WreathProductElem)(a::Groups.Automorphism)
+    A = parent(a)
+    g = AutFG_emb(A,g)
+    res = A()
+    Groups.r_multiply!(res, g.symbols, reduced=false)
+    Groups.r_multiply!(res, a.symbols, reduced=false)
+    Groups.r_multiply!(res, [inv(s) for s in reverse!(g.symbols)])
+    return res
+end
+
+function (p::perm)(a::Groups.Automorphism)
+    g = AutFG_emb(parent(a),p)
+    return g*a*inv(g)
+end

groups/autfreegroup.jl

@@ -19,41 +19,3 @@ end
 function autS(G::SpecialAutomorphismGroup{N}) where N
     return WreathProduct(PermutationGroup(2), PermutationGroup(N))
 end
-
-###############################################################################
-#
-#  Action of WreathProductElems on AutGroupElem
-#
-###############################################################################
-
-function AutFG_emb(A::AutGroup, g::WreathProductElem)
-    isa(A.objectGroup, FreeGroup) || throw("Not an Aut(Fₙ)")
-    parent(g).P.n == length(A.objectGroup.gens) || throw("No natural embedding of $(parent(g)) into $A")
-    elt = A()
-    Id = parent(g.n.elts[1])()
-    flips = Groups.AutSymbol[Groups.flip_autsymbol(i) for i in 1:length(g.p.d) if g.n.elts[i] != Id]
-    Groups.r_multiply!(elt, flips, reduced=false)
-    Groups.r_multiply!(elt, [Groups.perm_autsymbol(g.p)])
-    return elt
-end
-
-function AutFG_emb(A::AutGroup, p::perm)
-    isa(A.objectGroup, FreeGroup) || throw("Not an Aut(Fₙ)")
-    parent(p).n == length(A.objectGroup.gens) || throw("No natural embedding of $(parent(g)) into $A")
-    return A(Groups.perm_autsymbol(p))
-end
-
-function (g::WreathProductElem)(a::Groups.Automorphism)
-    A = parent(a)
-    g = AutFG_emb(A,g)
-    res = A()
-    Groups.r_multiply!(res, g.symbols, reduced=false)
-    Groups.r_multiply!(res, a.symbols, reduced=false)
-    Groups.r_multiply!(res, [inv(s) for s in reverse!(g.symbols)])
-    return res
-end
-
-function (p::perm)(a::Groups.Automorphism)
-    g = AutFG_emb(parent(a),p)
-    return g*a*inv(g)
-end

groups/speciallinear.jl

@@ -60,46 +60,3 @@ end
 function autS(G::SpecialLinearGroup{N}) where N
     return WreathProduct(PermutationGroup(2), PermutationGroup(N))
 end
-
-###############################################################################
-#
-#  Action of WreathProductElems on Nemo.MatElem
-#
-###############################################################################
-
-function matrix_emb(n::DirectProductGroupElem, p::perm)
-    Id = parent(n.elts[1])()
-    elt = diagm([(-1)^(el == Id ? 0 : 1) for el in n.elts])
-    return elt[:, p.d]
-end
-
-function (g::WreathProductElem)(A::MatElem)
-    g_inv = inv(g)
-    G = matrix_emb(g.n, g_inv.p)
-    G_inv = matrix_emb(g_inv.n, g.p)
-    M = parent(A)
-    return M(G)*A*M(G_inv)
-end
-
-import Base.*
-
-doc"""
-    *(x::AbstractAlgebra.MatElem, P::Generic.perm)
-> Apply the pemutation $P$ to the rows of the matrix $x$ and return the result.
-"""
-function *(x::AbstractAlgebra.MatElem, P::Generic.perm)
-   z = similar(x)
-   m = rows(x)
-   n = cols(x)
-   for i = 1:m
-      for j = 1:n
-         z[i, j] = x[i,P[j]]
-      end
-   end
-   return z
-end
-
-function (p::perm)(A::MatElem)
-    length(p.d) == A.r == A.c || throw("Can't act via $p on matrix of size ($(A.r), $(A.c))")
-    return p*A*inv(p)
-end