From fc4b01a1930fabe90fed4dee698ff8df66c24396 Mon Sep 17 00:00:00 2001
From: kalmarek <kalmar@amu.edu.pl>
Date: Sun, 30 Jun 2019 19:55:56 +0200
Subject: [PATCH] broaden signature of generate_balls to include NCRingElems

---
 src/Groups.jl    |  6 ++++--
 test/runtests.jl | 12 ++++++++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/Groups.jl b/src/Groups.jl
index a038e99..909473c 100644
--- a/src/Groups.jl
+++ b/src/Groups.jl
@@ -425,7 +425,8 @@ end
 #
 ###############################################################################
 
-function generate_balls(S::Vector{T}, Id::T=parent(first(S))(); radius=2, op=*) where T<:GroupElem
+function generate_balls(S::AbstractVector{T}, Id::T=parent(first(S))();
+        radius=2, op=*) where T<:GroupElem
     sizes = Int[]
     B = [Id]
     for i in 1:radius
@@ -436,7 +437,8 @@ function generate_balls(S::Vector{T}, Id::T=parent(first(S))(); radius=2, op=*)
     return B, sizes
 end
 
-function generate_balls(S::Vector{T}, Id::T=one(parent(first(S))); radius=2, op=*) where {T<:RingElem}
+function generate_balls(S::AbstractVector{T}, Id::T=one(parent(first(S)));
+        radius=2, op=*) where {T<:NCRingElem}
     sizes = Int[]
     B = [Id]
     for i in 1:radius
diff --git a/test/runtests.jl b/test/runtests.jl
index 8364bf0..6f55d86 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -5,6 +5,18 @@ using Groups
 using LinearAlgebra
 
 @testset "Groups" begin
+
+   @testset "generate balls" begin
+      M = MatrixAlgebra(zz, 3)
+      w = one(M); w[1,2] = 1;
+      r = one(M); r[2,3] = -3;
+      s = one(M); s[1,3] = 2; s[3,2] = -1;
+
+      S = [w,r,s]; S = unique([S; inv.(S)]);
+      _, sizes = Groups.generate_balls(S, radius=4);
+      @test sizes == [7, 33, 141, 561]
+   end
+
    include("FreeGroup-tests.jl")
    include("AutGroup-tests.jl")
    include("DirectPower-tests.jl")